5.3 owners, what real world mileage are you getting?

[Spong]

I'm just wondering what those of you with 4x4 Trailvoys with the 5.3 engine are getting for gas mileage? Please list you gear ratio as well. I have 3.73's.

I ask because mine seems to be getting worse. I've been keeping a log of my mileage. I'm at about 10,600 miles right now, mostly interstate/highway miles. When on the interstate I run normally between 75-80. When I had a Wait4ME tune (required premium) I was getting 17-19 driving those speeds on interstate trips. I now have a PCMforless tune (regular fuel) Today I drove from Omaha to Quincy IL. I got 16.8 mpg running about 75. I then went onto a 4-lane highway where I dropped the speed to 65-70 and bumped to the lower 18's. The first tank had some 89 w/crapenol on it and then next 2 stops I put in regular 87 non-crapenol which probably accounted for some increase. I know the Ethanol will drop 1-2 mpg. I'm wondering if others are getting about the same or better? I've been noticing my mileage staying in the 16's most of the time now. :confused:

Thanks,
Steve

[ScarabEpic22]

Wow, that seems a little low to me man. I get ~14 around town but at 75mph cruising with 5 people in the car, a truck full of ski gear, and a rocketbox I got 19-21mpg. And, I was stopped for about 15min on I5 b/c of an accident so that definitely didnt help my mileage.

[Spong]

I keep thinking as the miles increase, the mileage will improve. :undecided

[turbomike]

05 Rainier 5.3 w/3.73's, stock, 2wd

city driving: 16-17
suburban driving: 17.5-18.5
65mph: 22.5-23.0
70mph: 21.0-21.5
75mph: 20.0-20.5
80mph: 19.5-20.0

pulling 5200lb car and trailer @ 75mph in OD: 13.5-15

[Spong]

05 Rainier 5.3 w/3.73's, stock, 2wd

city driving: 16-17
suburban driving: 17.5-18.5
65mph: 22.5-23.0
70mph: 21.0-21.5
75mph: 20.0-20.5
80mph: 19.5-20.0

pulling 5200lb car and trailer @ 75mph in OD: 13.5-15


Those are pretty nice numbers!!! Being 2wd sure doesn't hurt! ;)

How many miles on your Rainier?

[Clayton]

I'm at about 18000 miles on my truck... 3.73 ratio...

most of my driving is to and from work, which bounces between 35 and 60...I average high 15's...I tend to be on it almost everywhere though. Even in the 25 zones...someone who's going 25 turns off and I like to floor it :D

When I make my runs down to SoCal (400 miles cruising at 75) I can get 20 flat, haven't seen anything better than that though.

Can't complain, however...when I drove my parents I6 98 Grand Cherokee, I averaged 16-17 for my around-town driving.

[turbomike]

Just turned 50k this morning on a trip from Dallas to Oklahoma City. Running 75 netted 21.8 without air on and a slight tail wind.

[mrbell83]

05 Rainier 5.3 w/3.73's, stock, 2wd

city driving: 16-17
suburban driving: 17.5-18.5
65mph: 22.5-23.0
70mph: 21.0-21.5
75mph: 20.0-20.5
80mph: 19.5-20.0

pulling 5200lb car and trailer @ 75mph in OD: 13.5-15

Should you be pulling that kind of weight with OD on?

[MrNorthFace]

Trying to see what my computer was saying this morning on my way to work. Mind you.....there are alot of slight ups& downs, twists & turns & I tried to check it on even ground....but it was all very brief.

Anywhere from 50-60MPH, I was getting 21-23MPG.

Couldn't go any quicker & nowhere to slow down. Not bad for my lead sled.

[muddy tires]

My DIC reads an average of 17.7 L/100 km. I think I'm 3.42:1 with G80. This includes a couple hundred km's pulling my snowmobile trailer to put them to bed for the season, some highway travel and mostly city driving. My best reading was an average 11.3 L/100 km (range of 818 km on fillup :woot: ). (Highway run with a light foot ~ 90 km/h mostly.) When pulling my travel trailer I can easily see mileage in the 20's :sadcry:

ps. I'm driving an EXT 4X4

[Dave]

I make frequent trips to Boise, Idaho to visit my Dad. Here are the stats for both of my 5.3s.

03 TB EXT 4x4, 3.42 gears
Around 19mpg cruising at 75mph. I think it dropped in the 16s one drip during real high headwinds, 21mpg taking the scenic route (mountains, below 70mph)

06 Denali 4x4, 3.73 gears
Around 20mpg cruising at 75mph. Dropped into the 17s with strong head wind. Averaged 23mpg one time cruising across Nevada on US6 at 75mph (no traffic). About 22 on the same mountain trip as above.

In California I'm lucky to get 18mpg with the Denali and that is cruising at 70mph on Hwy 99. I think it is because of their environment friendly gas there.

[Nukedog]

3.42 gears on the short TB

19 highway at 72mph

15 city

Same as my 5.3 Silvy with 3.23 gears...

[Spong]

Damn, something must be wrong with mine! :hissy:

[titanium10k]

07 5.3 liter 4x4 3.73. In town I average about 17 or so and on the hwy going 70 I get about 21.

[blueblazer5_3]

My DIC reads about 9.5-12.0 miles per gallon. I don't drive hard and if I really baby it, I'll get about 17mpg.

I think I'll have to go to the dealer for mine. Actually calculated my mileage and it's about 15 miles per gallon highway...

That sucks!!!:duh:

[ennzzo]

5.3 Envoy XL 3.42 G80

16 city
18 hwy

[localeye]

2006 Envoy Denali
i'm getting 14...sucks.

[Gunz]

Well, I get 2 different mileage sets for different OCtanes for my 3.73/SWB model.

87 BP, Sunoco, or Shell (no off-brands)
Town 15, HWY 19, Mix 17 on a full tank, running close to 350 at fill up

93 BP, Sunoco, or Shell
Town 15, HWY 21 @ 70-75 cruise control, mix 20 on tank, running to 410 miels max at fill up.

Naturally, this is a hwy long trip vehicle. This is not an errand vehicle for me. I hate using it for trips I know will be short.

[Spong]

On my last 2 fillups coming home last Thursday, I got 19.03 and then 19.6. Once I got all the ethanol garbage out of the system it helped! From now on, only 87 w/o corn in my tank.

[Envoy Fan]

On my last 2 fillups coming home last Thursday, I got 19.03 and then 19.6. Once I got all the ethanol garbage out of the system it helped! From now on, only 87 w/o corn in my tank.


Sounds like some decent numbers on the mileage :yes:

Wish we could get corn free fuel here in Ohio :sadcry: :hissy: :hissy:

[pnwext]

2005 4x4 TB EXT
5.3L w/3.73 G80

I average 17.7 for all around driving. Last long trip at speeds around 70-80 mph was around 20.0 to 21.5. I keep the transfer in the 2wd mode - haven't checked it in the AWD mode yet?

To me this is great compared to my older suburban I used to drive - maybe 12.

[Spong]

Sounds like some decent numbers on the mileage :yes:

Wish we could get corn free fuel here in Ohio :sadcry: :hissy: :hissy:

You don't have a choice? Even here in the corn state with the Ethanol mafia, we still can avoid E-10 by buying 87 or premium. There are a few stations that have E-10 in all grades of fuel but it's posted on the pump. In NE & IA the mid grade fuels (89-90) octane are E-10 about 95% of the time and also priced the lowest thanks to subsidies. I like when I travel through MO since most stations are E-10 free in all grades and "regular" 87 is the cheapest. There are some stations with E-10 but it's posted on the pump so I know to avoid it. WI also is mostly ethanol free, for now anyway.


2005 4x4 TB EXT
5.3L w/3.73 G80

I average 17.7 for all around driving. Last long trip at speeds around 70-80 mph was around 20.0 to 21.5. I keep the transfer in the 2wd mode - haven't checked it in the AWD mode yet?

To me this is great compared to my older suburban I used to drive - maybe 12.

Wow, that's amazing mileage!! :eek:

[Nukedog]

On my last 2 fillups coming home last Thursday, I got 19.03 and then 19.6. Once I got all the ethanol garbage out of the system it helped! From now on, only 87 w/o corn in my tank.

You are lucky right now - it will all be E85 soon...

[Spong]

You are lucky right now - it will all be E85 soon...

Eh, I don't think so. People are slowing getting wise to the con that is Ethanol. Once people see the 40% drop in MPG with E85 the wheels start to turn! I know mandated E10 isn't that far off but E85 doesn't make economic sense.

[2lucky]

3.42 Gears S/W base. 4X4 No drivetrain mods.
11/12 City
17/18 Hwy
87 octane.
Winter gas and cold temps dropped City to 9 mpg.:duh:
Current milage: 3700
I also hope to see improvement with mileage.:confused:

[Envoy Fan]

You don't have a choice? Even here in the corn state with the Ethanol mafia, we still can avoid E-10 by buying 87 or premium. There are a few stations that have E-10 in all grades of fuel but it's posted on the pump. In NE & IA the mid grade fuels (89-90) octane are E-10 about 95% of the time and also priced the lowest thanks to subsidies. I like when I travel through MO since most stations are E-10 free in all grades and "regular" 87 is the cheapest. There are some stations with E-10 but it's posted on the pump so I know to avoid it. WI also is mostly ethanol free, for now anyway.


No choice in Ohio. The gasoline companies in Ohio are not regulated by the State, so that they can put anything in the pumps that they want. There is no labels on the pumps telling consumers what they are getting. We have to take the station's word on octane that we are getting 87, 89, etc. The states are not regulated and tested for the protection of the consumer. There are some area regulations for fuel blends to cut down on emissions, no telling what or how much corn they are putting in the pump for this requirement.

[03 SVT VERT]

2007 Envoy Denali with 3.42 rear
I get 21 highway (as long as I keep it under 70, over 70 it drops to 19) and a pretty solid 12-13 around town.

[Spong]

No choice in Ohio. The gasoline companies in Ohio are not regulated by the State, so that they can put anything in the pumps that they want. There is no labels on the pumps telling consumers what they are getting. We have to take the station's word on octane that we are getting 87, 89, etc. The states are not regulated and tested for the protection of the consumer. There are some area regulations for fuel blends to cut down on emissions, no telling what or how much corn they are putting in the pump for this requirement.


Are you serious! That's crazy! I can't believe you don't have some sort of state oversight. :weird:

[Envoy Fan]

Are you serious! That's crazy! I can't believe you don't have some sort of state oversight. :weird:

Oil company campaign contributions to politicians. :x

[Spong]

Oil company campaign contributions to politicians. :x


So nobody checks the pumps either to see if they are correct? Does OH have a dept of weights and measures?

I just can't believe that there's no govt agency that verifies the pump's accuracy and checks the octane rating.

[Envoy Fan]

So nobody checks the pumps either to see if they are correct? Does OH have a dept of weights and measures?

I just can't believe that there's no govt agency that verifies the pump's accuracy and checks the octane rating.

Each county is responsible for the pump dispensing the correct amout of fuel, (annually certified) so that part is covered. What is not covered is octane ratings and no sticker on side of pump to tell what kind of fuel you are getting (E-10, etc.)

Asking a clerk if the fuel has ethanol in it is a waste of time. Answer is "what is ethanol"? They are totally clueless.

[03 SVT VERT]

In NJ all pumps are E10, in fact all pump gas contains ethanol now since ethanol is used as the oxygenate (ever since MTBE was banned). It's just a matter of how much.

[Spong]

Well I guess if you MPG goes up by about 2 then you know you DIDN'T have E10 in the last fillup!!

Every GM truck I've owned gets about 2mpg less with E10.

[Envoy Fan]

Well I guess if you MPG goes up by about 2 then you know you DIDN'T have E10 in the last fillup!!

Every GM truck I've owned gets about 2mpg less with E10.

:iagree: Regular gas in our area is quickly approaching $3.00 per gallon. Reason given is increased demand. Now with about everyone burning the E10 corn crap and getting less MPG, they are having to buy more fuel to go the same distance.

The gas companies are totally winning on this. Put in E10, people get less MPG. Oh wait, we have more demand for our fuel so we can charge more per gallon :mad: :mad: :hissy: :hissy: :hissy:

[Spong]

Yeah, Ethanol is a total con job. I wonder how many decades it will take before people pull their heads out of their asses and realize it. Maybe when Corn flakes cost $15/box thanks to "corn demand" :hissy: :rolleyes:

[03 SVT VERT]

I still can't believe diesel hasn't caught on yet. If more people ran diesel it would bring fuel costs down considerably because of its greater efficiency.

[Spong]

I still can't believe diesel hasn't caught on yet. If more people ran diesel it would bring fuel costs down considerably because of its greater efficiency.


I would love to have diesels. Diesel fuel USED TO be cheaper. There's really no reason for it to be more expensive than gasoline. Also keep in mind you pay more for the diesel engine (sometimes close to $10k more in trucks) so when you figure that cost plus the higher fuel costs, you never break even.

I almost bought a new diesel Jetta a few years ago. They wouldn't budge on the price. Back then it would have made economic sense because diesel fuel was cheaper. VW still won't budge on the price of their diesel cars but now with higher fuel costs, the extra $$$ you pay for the diesel isn't justified.

[03 SVT VERT]

In the trucks it is expensive because the new diesels are basically performance engines. Instead of being equal with their gas counterpart, they are made to be much more powerful. However, the diesels used in Mercedes, Jeep, VW, ect are generally only $1,000 more than a gas engine. While that sounds like a lot, the government gives diesel buyers a $3,400 tax credit. While fuel is still currently more expensive than regular (around mid-grade price) you still save more money than a comparative gas vehicle thanks to diesel's greater efficiency.

[jrpjr61]

05 TB 3.42 rear

Highway 75-85 mph --- 18-19 mpg

around town ---- 11-12 mpg

I was babying it around town in hopes of getting higher mileage , then I gave up and said S*** it might as well get on it now and then. The mileage did not change.... strange.

[Spong]

In the trucks it is expensive because the new diesels are basically performance engines. Instead of being equal with their gas counterpart, they are made to be much more powerful. However, the diesels used in Mercedes, Jeep, VW, ect are generally only $1,000 more than a gas engine. While that sounds like a lot, the government gives diesel buyers a $3,400 tax credit. While fuel is still currently more expensive than regular (around mid-grade price) you still save more money than a comparative gas vehicle thanks to diesel's greater efficiency.


I didn't know about the $3400 credit. :undecided When did that start? Is that for trucks and cars? With a truck, if you buy the diesel you still have to drive 100k + miles before you ever break even. Around here the diesel is closer to premium gas in price.

I did a bunch of math last year when I was thinking about getting a diesel Jetta again. I'll have to find it. I wasn't figuring in a $3400 credit, but w/o the credit, even with the slightly better mpg, the cost of diesel was high enough that it never really made good sense. If you figure in depreciation (diesel VWs sell used for damn near new prices) of gas vs diesel then maybe it would make more sense.

[ScarabEpic22]

$3.00 a gallon Bill? You are lucky, I paid $3.49 yesterday and it is supposed to be going up again today...:mad: :mad: This is going to make my summer plans a little more difficult, but it doesnt mean Im going to run out and buy a Prius.

[ronbrau]

Only had car couple months. Verified speedo & odom accuracy. Don't trust yet the computer, I keep track of miles & fill tank. Hiway at 65 is at least 20mpg. Mix of rural & hiway is 17-19 depending on mix ratios. Don't do much stop & go city driving (Peoria, Il area) but suspect mileage is <16.

[Clayton]

I'm going back on my old post!

I followed some school busses to the bay area this weekend, 24 mpg baby!

Filled up before I left, probably didn't have to fill up on my way back but I did.

Got 383 miles on 3/4 of a tank. Typically around my hometown I'm getting abour 200-250 miles per tank.

[localeye]

i'm getting a whooping 14.3

[Denali88]

4x4 envoy gettin bout 16-18 city and 18- 21 highway all depends on how fast I drive im averagin about a 18mpg as of now

[Zibby]

07 4X4 3.42

First Tank 14mpg(I think the dealer didn't fill it up completely)
2nd Tank All City Driving 18.1mpg
3rd Tank All Highway 18.9mpg

I'm happy so far. I hope after it breaks in I'm over 20. If not a good tune will do it for me.

After reading this thread I have a few other comments too:
1)Yeah you can complain about the ethonal but it is better for the envirorment. I'm not a tree hugger but I do want to know I'm grand kids can enjoy the great out doors when I'm gone...I call it an enviromental investment.
2)I did the same comparison about diesel vs gas. But I ws looking a an HD pickup to pull the camper. It was a 6K adder....The new Dmax is 8K adder...I think? When diesel was a little cheaper then gas GM figured it would take 5 years to pay back. IMO not bad becasue in 5 years you would need to trade that Gas truck in anyhow. And that did not consider Resale. With my crazy math considering I put 25K/year on my truck I could easly have it paid for in 3 years. But now with the current diesel prices and 8K adder....it will take 10years to pay back.

my :m2:

[Spong]

After reading this thread I have a few other comments too:
1)Yeah you can complain about the ethonal but it is better for the envirorment. I'm not a tree hugger but I do want to know I'm grand kids can enjoy the great out doors when I'm gone...I call it an enviromental investment.


I think that's still debatable. It's like electric cars, on the surface they seem wonderful until you really look at everything that goes into it. The same with ethanol (which I pay more to AVOID when I pump up) there's alot that goes into making it that isn't so great for the environment.

Not to mention, Ethanol gets less MPG too.

[kadillackelley]

We just bought a 2005 trailblazer ext with 13k miles on it-5.3 V8
with 3.73's. First trip to Ocean City MD was about 260 miles-21 mpg with speeds varying from 55-80 mph-on average about 65 mph. We've been getting about 17 mpg around town. I would like to put a cold air intake and exhaust on it to see if it improves.

[Spong]

Damn, I wouldn't be complaining about 21mpg, especially in a EXT model!! :eek:

[Zibby]

I think that's still debatable. It's like electric cars, on the surface they seem wonderful until you really look at everything that goes into it. The same with ethanol (which I pay more to AVOID when I pump up) there's alot that goes into making it that isn't so great for the environment.

Not to mention, Ethanol gets less MPG too.

Less Tailpipe emmissions is not debateable. The big picture has yet to be proven. But ethanol makes much more sense to me then Electric cars. Unless they find a way to make and electric car without batteries....

Sorry for jumping off topic...

[Super 88]

Less Tailpipe emmissions is not debateable. The big picture has yet to be proven. But ethanol makes much more sense to me then Electric cars. Unless they find a way to make and electric car without batteries....

Sorry for jumping off topic...

I have to agree with Spong here. I'd love to see real world numbers of emissions outputs that show a significant difference. Also, if you are burning more fuel (gasoline with ethanol) to go the same distance, how is that helping the environment? Many people like myself who live in states where the ethanol is mandatory, go to other states that do not use the ethanol and find an increase of at least 1-2 MPG.
Not to mention (I think someone else already did) what about the resources used to make the ethanol? I'm all for "saving the environment" where possible, but I really think ethanol is a BAD idea - unless you are a corn farmer. :)

[Envoy Fan]

I have to agree with Spong here. I'd love to see real world numbers of emissions outputs that show a significant difference. Also, if you are burning more fuel (gasoline with ethanol) to go the same distance, how is that helping the environment? Many people like myself who live in states where the ethanol is mandatory, go to other states that do not use the ethanol and find an increase of at least 1-2 MPG.
Not to mention (I think someone else already did) what about the resources used to make the ethanol? I'm all for "saving the environment" where possible, but I really think ethanol is a BAD idea - unless you are a corn farmer. :)

:iagree:

This corn fuel has me thinking it is a "feel good" political move. But since those that use it get less mileage they need to buy more gas to go the same distance. It is no wonder that gas demand is up from last year, even with the higher prices. You now have to buy more gas to go the same distance as you did with non ethanol blended fuel.

And, since corn is in so many other products, all of them have had price increases at the grocery store. Cereal, chicken, beef, milk, etc, etc.

The corn fuel has increased the price of gas and any product it touches. As consumers we are getting totally skewered. (The forum won't let me say ****ed)

Back on topic, my 5.3L Envoy has never gotten over 19 MPG. But I do enjoy driving it. :cool:

[Hardtop]

15@ 70-80?? 4X4 EXT w/ 44,000 miles I have 265/65-17 which are just ever so slightly taller. I am also using synthetic m-1. I just read a post that said it cuased a lower MPG in his TB. I may switch back to dino just to find out.

[Zibby]

Sorry for the :hijacked

I'll keep it short. I have done allot of reading on the corn fuel in the last few days. And even though it saves the emmissions currently regulated...it has other equally harmful emmissions. I have to agree that the corn fuel does not appear to be making much of a differnece, sorta like the electric cars. On the surface they sound good but not the big picture. But I beleive we are working in the right direction. We need to do soemthing. Being a country boy...I can't beleive the smog in the big cities.

[blownv6]

We just bought a 2005 trailblazer ext with 13k miles on it-5.3 V8
with 3.73's. First trip to Ocean City MD was about 260 miles-21 mpg with speeds varying from 55-80 mph-on average about 65 mph. We've been getting about 17 mpg around town. I would like to put a cold air intake and exhaust on it to see if it improves.


Not another Pennsyltuckian in Ocean City!!!!!!!!!!! NOOOOOOOOOOOO

jk, (inside joke) That's fantastic gas mileage

[GusMan]

For my TB, I tend to get about 15-16 in the city and 19 on the hwy. I have never topped 20 but ever since I got new tires, the mileage appears to be going up.

As for the use of E85, there are drawbacks and there are advantages. While some of the drawbacks have already been talked about I think the big thing is to at least try to reduce our dependence on foreign oil. Now, I think E85 technology, while not a new technology for some, is more of an under-researched one. I think in the future it may be a big part of our fuel sources especially if they are able to start creating it from non-food sources. Like any new technology, the cost of producing it is going to be high at first but I bet even that will start to go down as well.

I hope it really does help reduce our oil dependence like it says it will, but I am not going to hold my breath for a while.

[Dave]

The only problem with oil is that if something happens bad in that country (say Venezuela) then the price of gas goes up everywhere. Instead they should allow the price to vary by country (won't happen with OPEC) and by from the country that is somewhat stable.

But that is the problem, not many foreign oil companies are really that stable. Maybe UAE, but not Iran, Iraq, Nigeria and Venezuela.

I agree with numerous other people here is how can E85 be good for the environment because it is not as efficient as pure gasoline?

I don't think electric vehicles is the answer either, short term yes, but what happens when they need to dispose of all those battery packs. I think someone on this site showed an article to where it costs more (from cradle to grave) to create, own and dispose of a Prius then it does a Hummer. Just reading an article on how the batteries are made caused me to be dizzy.

Both of my 5.3s get around 18-20 on the highway which I can't complain since they are both 4x4 and around 4700lbs each. The Denali with the shorter rear gears gets better gas mileage in the city though but they are both between 13 and 16.

[Spong]

First off, we're not talking about E85, that's a whole other animal all together. I'm talking about E10 (10% ethanol) which is more common. E10 commonly drops your MPG 1-3 points. E85 on the other hand can't even be burned in our Trailvoys. In GM vehicles where you can burn E85 (the ones called "Flex Fuel") the mpg drop is closer to 30-40% VS regular gas. If E85 was half the price then ok, but in most cases it's only slightly cheaper than gasoline. It seems pretty stupid IMO to get such a drastic drop in MPG with only a slightly cheaper price. It actually ends up costing you MORE to use E85! :duh::weird:

So back to the topic at hand. I'm in Wisconsin right now and we'll be back out here in August. By then, I should have my efans installed and the DOD turned off. It will be interesting to see what kind of MPG I get on that trip. My Malibu only got about 25mpg driving out here but it has less than 10k miles on it too. I also drove 80+ the whole way here. I'm sure I would get better if I slowed down but what fun is that!!:weird::D

[Super 88]

First off, we're not talking about E85, that's a whole other animal all together.
I was thinking the same thing!

I'm talking about E10 (10% ethanol) which is more common. E10 commonly drops your MPG 1-3 points. E85 on the other hand can't even be burned in our Trailvoys. In GM vehicles where you can burn E85 (the ones called "Flex Fuel") the mpg drop is closer to 30-40% VS regular gas. If E85 was half the price then ok, but in most cases it's only slightly cheaper than gasoline. It seems pretty stupid IMO to get such a drastic drop in MPG with only a slightly cheaper price. It actually ends up costing you MORE to use E85! :duh::weird:

:iagree: Good points.

[Nukedog]

Spong - you will like the DOD turned off. Smooth as a baby now...:D

[Spong]

Spong - you will like the DOD turned off. Smooth as a baby now...:D


Did you get yours turned off?

[Nukedog]

Did you get yours turned off?

Yep... Very nice. Makes a sexy time...:thumbsup:

[Spong]

Yep... Very nice. Makes a sexy time...:thumbsup:

:rotfl: Any effect on mileage that you could tell? I sometimes wonder if the surging might actually hurt the fuel economy. I should be getting mine done soon. :cool:

[Nukedog]

Seems to remain the same but i will have a better answer next week when i drive to Kansas Cit (1100 miles) - last time i averaged 19.05mpg at 74mph...

[Spong]

Seems to remain the same but i will have a better answer next week when i drive to Kansas Cit (1100 miles) - last time i averaged 19.05mpg at 74mph...

Dang, I should buzz down and meet you! lol I'm sure the drive is much better w/o the constant jerking from the DOD. :suicide:

[Nukedog]

My actual location will be Saint Joseph, Mo which is about 40 minutes north of KC on I-29.

I may venture up to the drag strip in Pacific Junction, Ia and bracket race my TB on the 24th...

[Spong]

My actual location will be Saint Joseph, Mo which is about 40 minutes north of KC on I-29.

I may venture up to the drag strip in Pacific Junction, Ia and bracket race my TB on the 24th...


Damn, you'll be close!! I live in Omaha, just up I-29 and I used to live in KC. I've blown through St Joe many times on I-29!

Let me know if you make it to the drag strip!!

[Nukedog]

Real world mileage. I drove from Jacksonville Florida to Saint Joseph Missouri the last 2 days.

1st leg of journey: 320 miles / 78mph avg. / 2200rpm svg. / 15.97mpg avg.
2nd leg : 321miles / 72mph / 2000rpm / 19.8mpg
3rd leg : 343miles / 75mph / 2100rpm / 18.7mpg

1st leg was Jax to Alanta with mixed city/highway
2nd leg was Atl to Paducah, Ky with mountains in Chattanooga but almost completely highway
3rd leg was Paducah to Columbia, Missouri with road work on I57 that kept me at 15mph for about 40minutes and rush hour traffic through Saint Louis.

This is a 5.3 / 3.42rear / 30.5" tires / PCMforless tune (89 tune) / stock intake / a/c on the whole trip / 89/91 octane whole trip / with 3 people and luggage.

Hope this helps.

[Spong]

Welcome to the Midwest Nukedog!! Thanks for posting, that's good info. So with the DOD turned off, it really didn't make much difference then?

Are you going to make it up to Pacific Junction?

[Nukedog]

Welcome to the Midwest Nukedog!! Thanks for posting, that's good info. So with the DOD turned off, it really didn't make much difference then?

Are you going to make it up to Pacific Junction?

I noticed ZERO difference with DOD disabled. I think i might make Pacific Sat - gonna call them tomorrow...

[Spong]

I noticed ZERO difference with DOD disabled. I think i might make Pacific Sat - gonna call them tomorrow...

Awesome! I can't wait to disable mine. I don't even like driving it right now with the surging.

If you think you'll be there, drop me a note or post. I'll try to make it over to see you! We've got plans to attend some College World Series events in the late afternoon.

[quadhauler]

I'm extremely displeased with my mileage. In town, on the last tank, it averaged 13.8 - which actually doesn't sound so bad. However, on the road trip this past weekend, it got 15.7. I admit that I was heavy footed at times, but I keep seeing much higher numbers here. I'm driving an 04 EXT, 5.3, 2WD, 3.42 non G80, K&N and PCMForLess regular fuel tune. I love how it runs, but I keep thinking about the original sticker: 16 City and 19 Highway. :dielaugh:

I cannot help but wonder if a 3.73 might help, since the motor is such a revver or if there is something else wrong. Why in the heck is the tailpipe so black? Have you ever noticed how clean the tailpipes are on other vehicles? Some GM's, such as Grand Prix's, or Expeditions, 150's and Excursions have a much cleaner exhaust. Why, my boss's V10 Excursion gets better MPG than my smaller TB. :weird:

[Dave]

On the highway the 3.42s would be better unless you do a lot of mountain driving. Winter gas also causes the Trailvoy to get less gas mileage. My Denali's mileage usually drops into the 18-19s on the highway during the winter but that is cruising at 75mph and not putting my foot into it. With 3.73s the tranny rarely has to shift down unless the grades are around 6% or more.

The K&N and tune might be affecting your gas mileage in a negative way. My Denali's exhaust pipe is not black so I wouldn't be surprised if one of those is causing your gas consumption increase.

Check your filter and adjust your driving style. Take a 200 mile drive or so and keep it at a legal cruising speed. If you still get bad gas mileage it is either the tune or another problem. I would estimate the 3.42s should put gas mileage around at least 20mpg. I'm even lugging around a 4x4 system which doesn't affect gas mileage too much on the highway anyways.

[quadhauler]

Thanks for your reply Dave. The stock tune was horrible and the mileage was even worse. I may swap in the stock air filter and check it out. The PCM tune actually picked up the mileage by about 1/2 mile per gallon. It was not unusual for this vehicle to get high 12's (in town) when it was all stock. My thinking was that the 3.73 may keep the motor from lugging so much... especially in town.

I also have to wonder if the calculations given by the factory computer could error on the high side. Does that sound like a conspiracy theory? :)

I took it back to GM several times and complained and they just laughed at me. I always hoped it would get better. I called GM Customer Service the other day and asked if I had options. They indicated, that even though it was out of warranty, they would be willing to help out with repairs. One problem: I'm afraid to take it in. One reason why is because I may have to pay for the diagnostics.

[Nukedog]

I use a calculator to check mine every tank full.

15.4mpg city
16.8mpg combined
19.4mpg highway

These are averages on a 5.3 / CAI / Tune / 3.42 gears and a happy foot...

[Envoy Fan]

Mileage also depends on the quality of fuel you are able to purchase. Some areas have fuel with a higher sulphur content. This may not be best for mileage.

[turbomike]

Best mileage I get is with 93 octane.

16 city
21 highway running 75-80

[Nukedog]

Best mileage I get is with 93 octane.

16 city
21 highway running 75-80

Very odd. You should get best mileage with lower octane since higher octane makes less HP in the low compression engines and burns less effiiciently.

[OneHotRT59]

Nothing but Corn Oil around here (chicago - milwaukee corridor)
Straight interstate around 17 - 17.5 @ 75-80 MPH :mad:
City / County around 15 - 15.5 (no goosing it)
City only 13-14 :(

When riding shotgun, about 2-3 mpg improvement !!! :sleepy:

2006 22,000 miles.
5.3 4wd EXT LT w/3.73 and rear posi

[DangerousTacos]

I think we're getting around 14-16 city driving in our Envoy Denali 2wd 5.3L V8. I think its 3.73 gears.

[turbomike]

Very odd. You should get best mileage with lower octane since higher octane makes less HP in the low compression engines and burns less effiiciently.

Pings like hell on 87 octane. Remember this is roughly a 10:1 engine.

[Zibby]

Over christmas break I did allot driving while I was home from japan.

@62mph>>21mpg AVG
@78mph>>17mpg AVG

I'm thinking it will be a little better with it warms up. Plus I only have 6K on it...

[blueblazer5_3]

Depends on how fast you accelerate, how much you get into the throttle when driving, what speed you are driving, hilly or flat, octane, ethanol fuel or not, I can keep going.

The main ones are keeping the vehicle in the "DOD" mode which is not easy unless you have the dashhawk. I can get 12 mpg overall any day of the week. Very hilly, stop and go driving. The other thing is on the highway when using the Dashhawk to keep the vehicle in DOD, I was getting 25 mpg. I did this the whole way home. Mostly flat highway driving at 70-75 mph. I would say check the air filter, check the O2 sensors and make sure they are switching like they should.

I would do the following to check mileage via the computer......When driving on the highway, set the DIC to average fuel mileage.....They hit the arrow (reset button) while drivng. THis allows you to see the "instant fuel mileage" that you are getting via the computer. If this is around 17-18 while steady on the gas, you're not bad.

This is what stinks about the TB or Envoy, you can't tell when you're in DOD mode and cannot keep it there.

Don

[Nukedog]

Pings like hell on 87 octane. Remember this is roughly a 10:1 engine.

Mine runs perfect on 87 octane with the more aggressive 89 octane tune and a CAI.

I use 93 octane in my 13/1 CR motorcycle with no issue and 87 on my 11.5/1 cycle. 10/1 is nothing on a aluminum cylinder for a C/R...

Use what you got to i guess...

[Mr_Brooks]

~19mph @ 80mph, ~16.5 around town, have seen ~23mph on flat highway @ 65mph.

[Envoy Fan]

~19mph @ 80mph, ~16.5 around town, have seen ~23mph on flat highway @ 65mph.
Some good numbers. Why not fill out your profile so we know what truck, year, etc. you have.

[ltdakheel]

i have 07 denali G/R 3.73 wieght of the car 2200 KG while cruising at 120 K/m almost 600 k/m but i only gain about 570 k/m becuase my driving is 80 % highway and 20% city and the octane iam using is 96 it,s help the the engine to shift from 8 to 4 and this only in cold days like now but in the summer where temp is 50 + only having 500 k/m full tank may because of the hot air and using of A/C thats all
thanks every one

[randygreer]

5.3, DOD, 3.73, G80, 4WD, Denali, 14 city, 22 hwy @ 65

[Spong]

I just can't beleive you guys are getting 21,22,23 etc. :eek:

[drjackson]

I usually end up calculating mine in feet per gallon. The higher numbers usually make me feel better.

no really, I get around 18 running 75 and around town probably 14-15. Anyway, its not good.

[Envoy Fan]

5.3, DOD, 3.73, G80, 4WD, Denali, 14 city, 22 hwy @ 65

What brand of gasoline are you using?

[dporter]

:)I have logged 15,386 miles on my 07 Denali and used 769.7 gals. of misc. 87 oct. fuel for an average of 19.98 mpg. I buy what ever is the lowest cost. My driving is around town and 2 major 6000 mi. trips west each year. I have the 3.7 gears. I think I am doing great for a 6000 lb. vehicle.

[DangerousTacos]

:)I have logged 15,386 miles on my 07 Denali and used 769.7 gals. of misc. 87 oct. fuel for an average of 19.98 mpg. I buy what ever is the lowest cost. My driving is around town and 2 major 6000 mi. trips west each year. I have the 3.7 gears. I think I am doing great for a 6000 lb. vehicle.

Your Denali might like it a little more if you put 89 octane in it instead. When we started filling our Denali up with it, it idled real smooth as compared to using 87. I've never used anything below 91 in the SS though.

[billy8380]

suburban driving: 18-19
Highway 65-75mph - 20-22.5

[Envoy Fan]

suburban driving: 18-19
Highway 65-75mph - 20-22.5

With the 5.3L V8? Which year truck?

[billy8380]

With the 5.3L V8? Which year truck?

2006 5.3 V8

[Spong]

Being 2wd helps a ton too. :yes:

I had a 08 TB rental a month ago in Michigan. It had just a tad over 7k miles on it and 3.42 gears with the I6 and I managed 19.6 highway driving. I was surprised.

[Cuda_Jim]

I'm getting 17 in town and 19-20 MPG on the hiway. Not sure what gear ratios I'm running. Now I gotta go look when the wife returns :)

[Kevs03GMC]

Hi all, just did a trip from Philly to Rays town Lake 400+ miles round trip. Involves mostly highway then all Pocono mt. 03 5.3 XL 4WD 3.42s got 19.1 mpg on 87 Sams Club.

[Spong]

I've noticed mine has been better lately. I've been getting in the 18's and even low 19's. Haven't really changed anything other than running Amsoil synthetic in the engine (had Mobil 1 synthetic before) which really shouldn't matter.

Maybe it's the new sprag gear and transmission rebuild! :excited:

[callaway15]

just curious...what do you think caused you to need a transmission rebuild on such a new vehicle?

[Spong]

just curious...what do you think caused you to need a transmission rebuild on such a new vehicle?

32,970 miles, just out of the factory warranty.

Thread about it here ---> http://forums.trailvoy.com/showthread.php?t=57739

[callaway15]

huh, well it's good that you had an extended warranty at least.

[Spong]

:offtopic:

huh, well it's good that you had an extended warranty at least.


I honestly think it was a fluke. It's been at least 15 years since I had to have transmission repairs on a vehicle and I've had many vehicles in that time period. The service writers told me my TB was one of (3) vehicles in the shop that week with the same sprag gear problem. Ext warranty paid for itself in one shot!

[Vagabond]

I'm just wondering what those of you with 4x4 Trailvoys with the 5.3 engine are getting for gas mileage? Please list you gear ratio as well. I have 3.73's.

I must need to look at a chip or something cause I have been getting nothing but 13-14 mpg since I bought it last year. I drive all city, rarely get it over 65, and this has never gotten better or worse with any additives or maintainence. As far as gear ratio it all stock under the hood, so maybe I should look into some upgrades.

[Spong]

I must need to look at a chip or something cause I have been getting nothing but 13-14 mpg since I bought it last year. I drive all city, rarely get it over 65, and this has never gotten better or worse with any additives or maintainence. As far as gear ratio it all stock under the hood, so maybe I should look into some upgrades.

If you drive all city then 13-14 isn't too unusual.

Gear ratio doesn't have anything to do with how stock it is. You can tell your ratio by checking the RPO sticker inside the glovebox door. GU6= 3.42 GT4= 3.73 I'm guessing you're 3.42

[EXT TRAILBLAZER]

wow
you guys wont believe my mileage
i was traveling on highway
and got 26 - 28 mpg
with a v8!!!! i was driving at around 65 -75 mph
all i have done is royal purple synthetic oil and k&n replacement filter

7 passengers

400 pounds of load

3.42 gears

:eek:

[Vagabond]

wow
you guys wont believe my mileage
i was traveling on highway
and got 26 - 28 mpg
with a v8!!!! i was driving at around 65 -75 mph
all i have done is royal purple synthetic oil and k&n replacement filter

7 passengers

400 pounds of load

3.42 gears

:eek:

You positive that wasn't Kilometers! LOL

[Super 88]

wow
you guys wont believe my mileage
i was traveling on highway
and got 26 - 28 mpg
with a v8!!!! i was driving at around 65 -75 mph
all i have done is royal purple synthetic oil and k&n replacement filter

7 passengers

400 pounds of load

3.42 gears

:eek:
You are right. I don't believe you!

[Lov2xlr8]

5.3, 4x4 , 3.42 gears and I average 15mpg around town, but I get great highway milage. I know this is going to sound dumb but I dont even know if I have DOD but im going to guess yes since there is such a huge difference between city and highway mileage.

[Spong]

wow
you guys wont believe my mileage
i was traveling on highway
and got 26 - 28 mpg
with a v8!!!! i was driving at around 65 -75 mph
all i have done is royal purple synthetic oil and k&n replacement filter

7 passengers

400 pounds of load

3.42 gears

:eek:

I'm not calling you a liar but I think something must be off in the calculations!

Being 2wd and close to sea level will give you better mileage but 26-28 is just off the charts!

5.3, 4x4 , 3.42 gears and I average 15mpg around town, but I get great highway milage. I know this is going to sound dumb but I dont even know if I have DOD but im going to guess yes since there is such a huge difference between city and highway mileage.

Yes, you have DOD. I do to but I had mine turned off.

[bartonmd]

You are right. I don't believe you!

A big "+1" on that...

Mike

[linneje]

On the highway, the DIC often shows 11 L/100km which is about 21.3 mpg (us) I think. This summer I usually show an average on the DIC of 13 L/100 km which is about 18 mpg (us) I think. The average includes the city driving at my destination, so I think this is still OK economy for a 5.3 engine (3.73 gear ratio).

I think the transport canada rating for this model is 23 mpg highway (canadian gallons) so my mileage seems about right. I think it is fine on the highway, but it is really poor in the city here.

[EXT TRAILBLAZER]

You are right. I don't believe you!

You positive that wasn't Kilometers! LOL
-MPG-
I'm not calling you a liar but I think something must be off in the calculations!


Being 2wd and close to sea level will give you better mileage but 26-28 is just off the charts!

A big "+1" on that...

Mike


well guys i wouldn't believe it either :nono:
but i wasn't at sea level it was a stretch from around 800 feet descending to sea level
but it was like a 4 hour long downhill it really wasn't steep at all you wouldn't even notice any difference in altitude
may be that's why :undecided
it was 45 degrees Fahrenheit
at night so i had the right conditions
for that sort of mileage

yet After the night drive it was more of 20 - 23 mpg
:woot: i'm still very satisfied

[Super 88]

-MPG-





well guys i wouldn't believe it either :nono:
but i wasn't at sea level it was a stretch from around 800 feet descending to sea level
but it was like a 4 hour long downhill it really wasn't steep at all you wouldn't even notice any difference in altitude
may be that's why :undecided
it was 45 degrees Fahrenheit
at night so i had the right conditions
for that sort of mileage

yet After the night drive it was more of 20 - 23 mpg
:woot: i'm still very satisfied

Was the alleged MPG from the Driver Information Center, or figured by hand?

[EXT TRAILBLAZER]

Was the alleged MPG from the Driver Information Center, or figured by hand?

:duh:
yes

i should of known :duh:

[Bat119]

I get 5.5 - 6 KM per liter city
6.5 - 7.5 highway
3.73 gears

I keep my DIT on KMs per liter and I have a copy of this chart in my TB


KM lt -- MPG Imp----KM Lt.--MPG Imp.
3--------8.6--------10------28.62
3.5------ 10--------10.5----30.05
4--------11.5------11------31.48
4.5------ 12.9------11.5----32.91
5--------14.3------12------34.34
5.5------ 15.75-----12.5----35.77
6--------17.18-----13----- 37.2
6.5------ 18.61-----13.5--- 38.63
7--------20.04-----14------40.06
7.5------ 21.47-----14.5----41.49
8--------22.9------15------42.92
8.5------ 24.33-----15.5----44.35
9--------25.76-----16------45.78
9.5------ 27.19-----16.5----47.21

That's all folks!
:m2:

[Super 88]

:duh:
yes

i should of known :duh:

What exactly does that mean? :confused:

[EXT TRAILBLAZER]

What exactly does that mean? :confused:

well you shouldn't really trust your DIC for fuel mileage you will get more accurate results
if you do it by hand
:)
but it still would be some good mileage
DIC won't be that off the exact mileage
im guessing around
24ish was the mileage :laugh:

[Super 88]

well you shouldn't really trust your DIC for fuel mileage you will get more accurate results
if you do it by hand
:)
but it still would be some good mileage
DIC won't be that off the exact mileage
im guessing around
24ish was the mileage :laugh:

I see!