MPG thread, only 2002 TB'S info

[pjaneiro]

Ok i was reading the multiple threads on the mpg issues, now from all that reading I still can't say if what i am getting is good or not, originaly i was getting a rough average of 10mpg city, no cai no tune no exhaust, i have a 18gallon tank it's a 2002 LT, my sticker says it should be around 17, A lot of people say they are getting that, but how big is their thank ? I think i am running on 3.73 gears, not sure, my vin says so, but i no longer have the sticker, therefor i am unsure if that's true, anyone can tell me if there's a mecanical way of telling ? since i got my exhaust my cai and the tune, i was able to do 14mpg but it dropped to 10 again....running 87 octane gas, the good stuff...I usually fill her up when the lights hits, i fill her up with 16 gallons, that usually gave me 165-170 miles now with all the mods i have 185-190..big woopie...

So my inital question is, for a 2002 lt with a 18gallon tank... what are your numbers ?

Thanks...

[jahames7]

3.73 gears, K&N 77 series, TBS (yea i know...), gettin about 19.5 mpg city/hwy mix. Temps here range from about 60 - 80 degrees.

[jahames7]

right after i posted i saw where you live. Cold weather will lower your mpg so if you live in a cooler part of Canada, that could be a factor.

[RozmerJJ]

My wife's 02' LS, 2WD 3.42's gets about 18 City/HW mix and about 22 on long trips.

[hp_2002grad]

Recently i was getting low mpg, so i changed out the spark plugs and have been averaging close to 21.5 mpg mixed city/highway since. I have an 02 ls with 85,xxx miles on it.

[pjaneiro]

Well the temps are at around 60, but the guy who had it before me told he was always getting that average, only when he bought new he was able to hit the 15-17, so i guess, there might be somethnig wrong somewhere....


i am getting no cel

:confused:

[pjaneiro]

what sparks did you use ? the 41-103 ? i was thinking about changing that, i have 55k on the truck...

[idreama300]

Have you tried cleaning the TB?

[pjaneiro]

Yup, and i did notice that it was filthy, there was a fiar amount of oil deposit there, i almost felt like taking the whole intake out and cleaning it. i just sprayed the interior with the cleaner and let the valves burn it out, i noticed a better throtle response, but no gains there...

[rbarrios]

are you running extra weight in the vehicle?
tires up to the right amount of pressure.
CEL light- have you turned the key to the point before you crank engine- is the CEL light actually lighting up during the test of all the dash lights?
Im not an 02- but do have an 03 LS built in 02.
the tanks in these is 18.7 gallons... I too refill with 16.7 gallons consistently. so thats in line with what you get when its time to fill up.
I will reach 300 miles on the 16.7 gallons in mixed city/hwy.
If you dont have the sticker in your glove box- you can call dealer and have them run your VIN #, or go down there and thell print you a list of the items yout TB came with.

[Blazernut]

Yup, and i did notice that it was filthy, there was a fiar amount of oil deposit there, i almost felt like taking the whole intake out and cleaning it. i just sprayed the interior with the cleaner and let the valves burn it out, i noticed a better throtle response, but no gains there...

The first thing that comes to mind is the case relearn thing for your tune. Alvin is adamant about getting that done. Did you do it yet?

The next thing is tire pressure. If you go by your sidewall tolerances and pump them up to within a few pounds of max pressure that will help too. If it's been cold you may be surprised at how low it can get and then kill your rolling resistance. May ride a bit rougher but it's sucking your wallet dry now.

Are you calculating that MPG in US or Imperial gal? Obviously the the US guys are on the smaller gallon and if they are getting 16 mpg on their little gallon then they would get 19 on our bigger gallon. Mathematically anyway.

What about your fuel filter? Is your performance there or do you feel as if it may be starving sometimes?

And then when the weather warms up it will all be much better! :suicide:

rbarrios - I too have an late 02 production 03 model. In the manual it says that if you have a RPO code "NNK" in your glove box then you would have the larger tank. I found that on mine from looking in the manual under fuel capacities. I only usually put in 68 litres when the light comes on.

B. :m2:

[pjaneiro]

I have the build sheet with my vin, the dealer got it for me, but i am still unsure about the gears, there is no weight in the truck for the moment, i am in the process of building the sub box, but i removed a lot of dead weight , i now have a dual exhaust setup, and stated in a previous thread i was able to loose about 170 pounds total... by removing the original exhaust and speare tire, I'll try changing the plugs tonight, the dealer told me to use the 41-103 for my engine, iridium tipped, is there other stuff i need to look at ? air sensors, o2 sensors ? I know it's a gas guzzler from the start, but damn, my ram 1500 with the 5.2l V8 used less gas...

[jag42420]

My 04 TB EXT 4x4 (5000lbs) gets 21-22mpg highway (100% highway) and 15-17 city with 3.73 gears. Tire sizes, driving conditions, driver habits, weight, options, road slopes, everything contributes.

[shepmankev]

I have a 2002 with k&n, gutted air box, intake resonator delete tube I made and exhaust and I usually get about 240-260 on a full tank to low fuel light. It was in the 220 range before I did the mods above. Mixed city/hwy driving also and 3.73 gears

[pjaneiro]

I was NEVER, even on 60% highway use able to get pass the 200 miles mark, i'll replace the fuel filter tonight, but i have no issues there...I am depressed by this, if i could get a steady of 16mpg i would be happy, My dodge stratus does about 325km per 60 liters, and I KNOW for a fact that that's awfull, but she's modded like hell :crazy:

[jag42420]

I also have a 25 gal tank, and get about 380-480 miles out of a full one on average city/highway, depending where I'm driving and whether I'm towing. I normally drive less than 5 miles, all in city. Only hit highway on vacations.

[Blazernut]

I was NEVER, even on 60% highway use able to get pass the 200 miles mark, i'll replace the fuel filter tonight, but i have no issues there...I am depressed by this, if i could get a steady of 16mpg i would be happy, My dodge stratus does about 325km per 60 liters, and I KNOW for a fact that that's awfull, but she's modded like hell :crazy:

That's what I get. 16 mpg US size gal (19 mpg imperial) for mixed driving. And a real heavy foot. :duh: but I'm going to work on that.

[JamesDub]

With my 02 with 33" tires, CAI and magnaflow in place of the resonator I was getting 12.4 mpg average . Then I just got a tune from PCM and I am getting 17 mpg average . Very happy about that . I can barely hit 300 miles after the light comes on and is running on vapors :thumbsup:

James

[pjaneiro]

You prolly got the spike in mpg because of the tire size adjustment, I am still wondering what can make this truck guzzle so much gaz, i am not the only one with this issue, alot of us are either getting 10mpg or 16mpg on the same tank of gaz....i'll be replacing the sparks, the fuel filter, checking for vacum leaks, hoses and all that, but in the meantime i'd like to have more reports on mpg on 18gallon fuel tanks...

[rbarrios]

how about disconnecting battery- letting it sit for 30 min. while you clean throttle body again.
then reconnect, and drive the TB gently- like a grandma so it relearns easy driving parameters....
its prob still using speed demons parameters...
this something thats feasible? Id try it... nothing to lose. and alot to gain if it works.

[MAY03LT]

I have an 03, all stock, and have been getting 19 mpg higway with stereo equiptment in the back and ethonol-dilluted fuel in the tank (Im sure Id be getting 23 highway on regular 87). Delaware sucks!

[crazytb]

check the o2 sensor...i remember hearing that it may affect it..not 100 percent though but form what i remember it can't kill your gas

[gmcman]

Definately 10 MPG means somethings wrong.....like you should be pulling a trailer wrong. I get 15-17 mixed and 20-22 hwy and I have 4:10 gears and a K&N.....same MPG w/o the K&N.

1) change your fuel filter
2) over 60K miles...change your plugs
3) Tire pressure won't give you a big enough boost from 32-34 to 40 or 44 PSI when you factor in wearing out the center of your tire.
4) If you want to venture on the O2 sensors then by all means do so....not a necessity but they will eventually fail so if all the above doesn't help you can at least have someone check their voltages and see if they are within spec. Alot of times the O2 sensor can give a false reading and still be within the parameters of the operating range but show a slightly lean condition to the ECM and in turn will dump more fuel to compensate...and not give any codes.

I would check a few known good running 4.2's and see what vacuum they pull at idle and steady at 2 or 3K RPM and see what yours reads. If yours varies by 2 mm/hg or more I would suspect a vacuum leak...causing more fuel to compensate. This is not a sure-fire way to check vacuum cuz all motors are different but it should at least give you something to go on. Good luck.

[gcurtiss79]

I am about the same. 14-17 city and 19-22 highway. All depends on how fast I drive. 10 MPG...ouch

[pjaneiro]

I have an 03, all stock, and have been getting 19 mpg higway with stereo equiptment in the back and ethonol-dilluted fuel in the tank (Im sure Id be getting 23 highway on regular 87). Delaware sucks!

on a 18 gallon tank ?

[Nixxx]

I am getting about 20 highway and 15 city. I reset the onboard calcualtor at my last fill-up and it read my avg. was 17.4 MPG by the end of the tank.

My daily drive to work is 74 kms (mix of highway/city) and I use 11.2 Litres to do it. Working it out it's about 15.6 MPG. I use Petro-Canada 87 gas.

I have 131000 kms on my 02 LTZ 4WD, bone stock. 10 is just not right :undecided

May I suggest dumping a bottle of injector cleaner into you next tank of gas...

[pjaneiro]

well i replaced the sparks, got myself a new fuel filter, and huh, i was looking for my o2 sensors, i found one right next to the exhaust manifold you can see it if you don't have the cai installed, but when i followed my exhaust down i did'nt find the other one, unless the previous owner removed the cat, but even then i can't find the simulator....or am i looking t the wrong place, i do exhaust, and i swear my exhaust line looks stock....there is no CAT... just a mini resonator 4 inch long :ugh: i'm getting too old for this lol....

is there a machanical way to verify i do have 3.73's, i read somewhere about drawing a line and turning something, i don't remember :cry:

[ScarabEpic22]

OK, right after the manifold there should be a cylinder like 4-6" long, thats the cat. Only 1 on the I6 b/c there is only 1 exhaust downpipe.

As for the gears, check your glovebox:
GU6- 3.42
GT4- 3.73
GT5- 4.10
G80- locking rear

Throw a bottle of Techron fuel system cleaner into your tank next time you fillup, and maybe get some Seafoam and suck it into the intake manifold via brake booster line to see if that clears it out a little.

BTW, Im getting 12.5-13mpg with Shell or Chevron 87 and a horrible lead foot. But, when I get on the hwy and cruise at 65 my DIC shows 23mpg (yes, for longer than 1sec, like a couple miles on the flats) and at 75 I get 20.5-21mpg.

02 I6 3.73+G80 4WD 78,9xx mi

[JamesDub]

You prolly got the spike in mpg because of the tire size adjustment, I am still wondering what can make this truck guzzle so much gaz, i am not the only one with this issue, alot of us are either getting 10mpg or 16mpg on the same tank of gaz....i'll be replacing the sparks, the fuel filter, checking for vacum leaks, hoses and all that, but in the meantime i'd like to have more reports on mpg on 18gallon fuel tanks...

Nope its not because of the tire size adjustment on the PCM tune cause... PCMforless botched that all up . My mileage and speedo are still 11% off . I calculate distance and MPH etc with a GPS . I'm a little pissed with PCMforless about that . But am happy with the improved mileage up to 17 mpg average . And my TB has the 18 gallon tank with 3.42 gears .

James

[jag42420]

A bad tune will affect mileage too. If you know someone close to you with HPTuners, they can adjust your tire size in the PCM. The wrong tire sizes and resulting improperly calibrated speedometer will result in your torque converter locking up wrong and KILL your mileage in third and fourth gear. Tire sizes are used by the computer to calculate when the converter is supposed to lock and unlock, and how the vehicle should run at certain speeds. Same thing with gears, PCM has to be updated for proper operation. How many of you with poor mileage have changed tire sizes or gears without recalculating the speedo?

[pjaneiro]

OK, right after the manifold there should be a cylinder like 4-6" long, thats the cat. Only 1 on the I6 b/c there is only 1 exhaust downpipe.

As for the gears, check your glovebox:
GU6- 3.42
GT4- 3.73
GT5- 4.10
G80- locking rear

Throw a bottle of Techron fuel system cleaner into your tank next time you fillup, and maybe get some Seafoam and suck it into the intake manifold via brake booster line to see if that clears it out a little.

BTW, Im getting 12.5-13mpg with Shell or Chevron 87 and a horrible lead foot. But, when I get on the hwy and cruise at 65 my DIC shows 23mpg (yes, for longer than 1sec, like a couple miles on the flats) and at 75 I get 20.5-21mpg.

02 I6 3.73+G80 4WD 78,9xx mi


Excuse my ignorance, what the is seafoam ?

[jag42420]

http://www.seafoamsales.com/motorTuneUpTechGas.htm

[pjaneiro]

i'll try teh seafoam as soon as i get back from work, i have two sensors one on my cai, and one on my intake manifold, can those be faulty and cause bad mpg ?

on another note i seem to have a small oil leak on one of the sensors located right next to the oil cap, if you look closely there is a round sensor, with a harness feeding that sensor, the upstream o2 sensor and other stuff, what does that sensor do ? Anyone knows ?

Thanks

[ds8]

It sounds like the sensor you are talking about is not a sensor at all. The Cam Phasing Valve is near the oil cap on the passenger side of the vehicle. It controls Variable Valve Timing. If it is leaking, it should be replaced, but should still provide proper function unless the oil pours out the back.

DS