Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

Type of Engine Oil

104K views 30 replies 15 participants last post by  Steve 33 
#1 ·
Hello,

I have an 04 Trailblazer 4.2l with 127,000 miles and its time for an oil change. I wonder if there is a particular brand (castrol, valvoline etc) that is preferred over others. Because it has so many miles, do I need to be looking at the high mileage engine oil?? What weight would be good for the vehicle? I dont haul anything, I live in SC and take long trips every once in a while. Any help is appreciated.:)
 
#2 ·
any noticeable oil leaks?

If it were me, I would put a premium (mobile1, Valvoline, RotellaT) high mileage oil in. Always go with what the manufacturer reccomends (5w-30).

I myself put Valvoline Max Life semisynthetic 5w-30 in at each oil change.
Make sure you get a good filter too. Wix is my favorite...
:m2:
 
#3 ·
I switched to full synthetic at 135k miles with mobil1 5w-30 and i couldn't be happier with the way the engine performs. I took the chance doing the switch at a high amount of miles though. Some may get lucky, some don't. Just stay away from Pennzoil platinum and quaker state.

Also, the poster above makes a good point. A good oil filter will only be beneficial. I personally use mobil1 but anything like wix or puralator is good as well.

5w-30 is recommended in these engines but if you're in a warmer climate you can do 10w-30
 
#7 ·
Personally I like Mobil 1 fully syn with Mobil filters, but on this truck I've stuck with castrol 10w30 they only had 5 of the 7 qts I needed, I know the owners manual says 5w30, but right below that it reads, you can use 10w30 if 5w30 is not available. However I did use Fram's high milage oil filter, recommended over 75,000..(I have 95,000..I don't know if it's that much better, but I didn't want the cheapest filter.:m2:
 
#8 ·
I know the owners manual says 5w30, but right below that it reads, you can use 10w30 if 5w30 is not available. However I did use Fram's high milage oil filter, recommended over 75,000..(I have 95,000..I don't know if it's that much better, but I didn't want the cheapest filter.:m2:
I'm not disputing what you are saying, but I find it interesting that in later manuals (my 05 in particular) they deleted that and said something to the effect of "Do NOT use SAE 20W-50 or any other viscosity . . . "

I use penzoil 10w40 high mileage. I keep hearing that it isnt good for my car, why is that?? What is wrong with penzoil? I dont have a problem switching to 5w30, just like to hear different opninons..
Many years ago - decades even, Pennzoil somehow got a bad rap for causing sludge. I've seen a lot of people go many 100's of thousands of miles using Pennzoil. EVEN IF it was true in the 60's or 70's I do not believe it is still the case.

On the other hand, I've used Mobil 1 in many of my vehicles and let's just say I was NOT impressed. Especially in the TB, the engine was noiser, the power was less and I believe the MPG dropped a little - not a lot but a little.
I think Pennzoil Plat. works better and it is a lot less money! 5 quart jugs at Wallymart are 20.00 and recently they had a 15.00 rebate!


As with many things, it is mostly a subjective thing. What works for one person may not work well for another.

Personally I like the A/C Delco oil filters. Unlike others I will not say "Fram is bad" because again I've used them for many decades over many hundreds of thousands of miles with NO problems ever!
However I do believe there are better filters out there for the same or less money. Purolator and Wix are two that come to mind.
 
#9 ·
I haven't had any leaks or anything since I've switched to penzoil hm years ago. I use fram filters, but will look into purolator as I have used it in the past. Thanks for the quick response. Will let u know the outcome after I change my oil monday.
 
#13 · (Edited)
lol i'm only 18, not old.

I don't have personal experience with valve problems but the amount of sludge did scare me while using PP.

i bought a car a couple years ago and the previous owner kept stating that he did oil changes by himself with regular penzoil (PYB) every 3k miles and not a mile over. We tore down the motor and did find a lot of sludge on it. i switched to PP and noticed a good difference. After about a year I tore it down again for the third time and noticed a small amount of sludge started to form again. Switched to mobil1 and engine was running smoother and quieter and felt like it was turning freely. I will be tearing it down once again so i can get the motor forged and we'll see how things are holding up with the M1. I'm not saying M1 is the only good oil out there, its just my personal preference of oil. Some may like PP, but for the extra $0.40/quart, i honestly think M1 would be a better investment. Again, thats just my :m2:
 
#14 ·
lol i'm only 18, not old.

I don't have personal experience with valve problems but the amount of sludge did scare me while using PP.

i bought a car a couple years ago and the previous owner kept stating that he did oil changes by himself with regular penzoil (PYB) every 3k miles and not a mile over. We tore down the motor and did find a lot of sludge on it. i switched to PP and noticed a good difference. After about a year I tore it down again for the third time and noticed a small amount of sludge started to form again. Switched to mobil1 and engine was running smoother and quieter and felt like it was turning freely. I will be tearing it down once again so i can get the motor forged and we'll see how things are holding up with the M1. I'm not saying M1 is the only good oil out there, its just my personal preference of oil. Some may like PP, but for the extra $0.40/quart, i honestly think M1 would be a better investment. Again, thats just my :m2:
Where do you get Mobil 1 for 40 cents more a quart than Pennzoil? I can get the quarts of Pennzoil Plat. at Walmart for 4.00 - but Mobil 1 is at least a buck and half or 2 dollars more a quart.

I can't comment on your experience with your one car other than to say you are mostly going by what the previous owner told you.

Also - while I didn't know your age - I wasn't for a moment suggesting you were old! :) Now - I'm old. I remember .19 cent a gallon gasoline - when oil came in cardboard type containers and you had to use a spout to pour the oil into your engine! And cars had points and condensers in the distibutor (I think I'll stop here before I start talking about the hand cranks) :D

As I said, oil usage is subjective. I tried Mobil 1 in all 4 of my current personal vehicles. I saw/felt NOTHING positive and in 3 of 4 cases saw negatives - so that's what turned me off to Mobil 1.
I really think it is overpriced for what it is. While many believe it is a "true synthetic" (or a group IV) I'm not convinced. This is another subject that has been well discussed over at BITOG and other places and we could discuss until the cows come home! :laugh:
 
#15 ·
Engine Oil

Thanks Super88 :D

I decided to stick with my Pennzoil, using the recommended weight. I appreciate the link that puts to rest the silly myth about the oil. I did switch my oil filter, from fram to purolator (which is what I used in the past).
 
#19 ·
Amsoil for me please!

I generally run either a Mobil 1, K&N (both are the same inside, only the outside can is different), or Wix (Napa gold) filter.

One thing to bear in mind when going up in viscosity (like 20W50) is that you will get WORSE fuel mileage, you will see things like the cam position solenoid fail, and you will also eventually have cold start wear and/or broken oil pump drive if you live in colder climates.

Our engines are designed for 5W30 and that is sufficient. Remember, it is viscosity that is changed, the lower number oils are not "thinner" (whatever that might mean).

Why Amsoil? Because it is a true long-chain molecule synthetic oil that has extended drain interval capacity. I change oil one time per year at about 20K miles. Have been doing so in all my engines since thelate 1970s.
 
#22 ·
High Mileage Oil Opinion

Right off the top I'm no expert... But I've been told that...
High mileage oils serve the purpose of swelling "O" Rings & Seals & Gaskets that tend to shrink, contract or decay over time and then leak. Additives in High Mileage Oil expand the rubber & rubber-like materials by means of chemically reacting with them and changing the seal's basic composition.
If you believe that leaks are present and want to try to correct them go ahead and use the high mileage stuff. (Don't use it just because of a perceived high number on your odometer.) Otherwise, if it ain't broke don't fix it. The chemical reaction does not necessarily stop when you want it to. Then the next thing you know, again over time, the seal loses its suppleness and gets irreversibly disintegrated.
Just Sayin' (I'm open to correction.)
 
#23 ·
I've found the high mileage oils to do just that ^^^^.

Once the seals soften up and get gummy, they go away faster than ever. No liquid replacement for actual hard parts, and hard parts like rubber or silicone seals harden with age and work (ever bent a wire until it broke? notice how it stiffens up from "working it? called work hardening and it happens to almost all materials eventually) and when they do, they chip or fail to be flexible enough to actually seal.

Best bet is to replace them.
 
#25 ·
I understand that is what you thought, but what was your reasoning for thinking that way?

Thicker, so it would not leak out or what?

Perhaps it is time for some oil education... Oil is not "thicker or thinner" with more or less lubrication properties based on "weight" (which is actually viscosity -- flow rate at temprature). Going up in numbers DOES NOT make oil lubricate better. It only changes the parameters in which the oil flows freely, and the idea is that the oil in our TrailVoy engines should flow freely at the lowest and highest operating temps.

The reason race car engines run 20W50 or other higher than standard viscosity (and these days very few actually do because that viscosity oil adds serious drag to reciprocating mass -- also virtually every "race" engine now runs full synthetic no matter which stickers are on the vehicle) is because of the seriously high operating temps that engines that turn 9000 rpm for hours at a time see. They don't race in the winter (and those who do would never run 20W50 or another higher than needed viscosity oil) because they want their engines to have peak performance at all times. Drag equals lower performence! Further, because race only engines have increased clearance between bearing shells and metal surfaces, and other metal reciprocating parts (again, to deal with metal expansion during extreme conditions during hours of racing) they require the slower flowing oils to handle those conditions while our stock engines do not.

http://www.upmpg.com/tech_articles/motoroil_viscosity/
 
#27 ·
The factory specs 5W30.

Economy will suffer with the higher weight oil, and it can also affect oil-sensitive items like the cam position actuator.

I am running 5W20 for winter and will swap it out to 5W30 for summer next spring. Of course, I live in Wisconsin where it gets rather cool on some mornings... Like -25F... :yes:
 
#28 ·
Stick to 5w-30, it is what the mfg recommends. The w stands for winter weight, or how we'll the oil flows at colder temperatures. To reduce wear, 5 is better than 10 because it flows better. Also, full synthetic is always better than Dino oil or blends. The synthetic oil will never break down like Dino oil does. My preference is Mobil1, available at Wally World for 24 for a 5 quart jug. Can't beat it.
 
#29 ·
I just bought Amsoil XL for $6.49 a quart.

With extended change intervals it becomes much less expensive than dino oil over the period of a year. Just add up 7 quarts dino oil plus filter X 7000 miles (or whatever frequency that one changes oil) versus 7 quarts of Amsoil plus filter at 15,000 miles. Even at a 2:1 ratio the Amsoil is less expensive and if one changes oil like grandpa at 2000 or 3000 miles, then the costs REALLY start to add up.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top