I was going to say that I was pretty sure the owner's manual for my 2004 Dale Jr car did not say synthetics were required for the supercharged engines.

I used to be a fan of synthetics and Mobil 1 in particular, but after doing multiple oil analysis on the 5.7L V-8 in my 98 chevy truck running 5W-30 Mobil 1, I switched back to conventional oil. My wear numbers were only allowing me to have 3,000 mile change intervels. I switched back to a conventional oil and my wear numbers went down and it was recommended that I could try 4,000 mile intervels. I only had about 75,000 miles on the truck when I quit using synthetics and I used Mobil 1 from about 1,500 miles to the 75,000 miles. I have not tried a synthetic oil since and with the prices of oil these days, I'm not going to start again.

I would like a conventional oil recommendation for my Supercharged 2004 Monte which will be needing an oil change pretty soon. What oil do you guys run. Thanks.

Wayne

 

If you're not going to use a synthetic oil, then I persoanlly recommend Valvoline conventional, or Mobil Clean 5000 conventional.

 

I will probably start using Valvoline conventional since I currently use it in all of my other vehicles. I used to use Havoline but Walmart quit carrying it and I could only find it at one autoparts store and they wanted almost as much as a synthetic for it.

I don't think that the 7.4L in my 98 K3500 truck likes Valvoline conventional because I'm getting quite a bit of engine noise that I didn't have with Havoline. I might have to switch back for that engine. Thanks for the recommendation.

Wayne

 

i always got good to great gas milege when i striped out all the regular lub engin and tranny and rear ends to synthetic. even with my monty i noticed the difference because one oil change i used regular oil in it it seemed like i heared alot of ticking and nocking and ended up doing a quick fast and in a hurry oil change back to synthetic. i was told by the dealer the car only used 0w-20 nothing heavy than that. they told me to becarefull if i went to 0w-30 or heaveyer like 10w-30 i would be needing a heavy engin over haul do to abnormal engin wier do to the heavy oil. also with the experence that i have threw the years if a car started on a light whieght oil threw out its life keep useing it do to age of the parts of the engine like oil pump bearings cam things like that

 

EXQUEEZE ME!!! Since when didn't ANY "GM High Performance Engine", whether the L67, LNF 2.0Lturbo, hi-perf' 'Vette's, etc NOT require the GM4718M oil??? That's the recommended oil. Check your owners manual, page 249.

The synthetics stand up better to the higher heats and pressures of these high compression engines.

Any NON high performance engine can use the standard oil with the classification of GM6094M.

Here is the list again of registered oils:

http://www.gm.com/corporate/responsi...ngine_oils.pdf

If you're driving an L-67, you should be using ONLY one of these recommended oils, or BETTER:

76 Super Synthetic Motor Oil 5W-30, 10W-30
AC Delco Full Synthetic 5W-30
Castrol Edge 5W-30, 10W-30
Castrol SLX Professional 4718 5W-30
Chevron Supreme Synthetic 5W-30, 10W-30
Coastal High Performance Full Synthetic 5W-30
Kendall GT-1 Ultimate Synthetic Motor Oil 5W-30, 10W-30
Mobil 1, 0W-20, 0W-30, 5W-30, 10W-30
Northland, Synergy Synthetic 5W-30
Pennzoil Platinum Full Synthetic 5W-30, 10W-30
Pinnacle National Synthetic 5W-30
Q HorsePower 5W-30, 10W-30
Service Pro Full Synthetic 5W-30
Texaco Havoline Synthetic 5W-30, 10W-30
Valvoline SynPower 5W-30, 10W-30
Warren Full Synthetic 5W

Oils like the Mobil 1 Extended Life oil is not on the list, nor is Royal Purple, because of extra or over the recommended limit of additives that GM has deemed harmful to the catalytic converter and/or the environment.

L-67 owners: LOOK FOR THE GM4718M CLASSIFICATION on the bottle.

 

I will have to check out that page in my owner's manual. My oil fill cap doesn't say anything about having to run synthetics like those on the vette or some of the other high performance GM vehicles I've seen.

The only way anyone is going to know for sure how an oil is performing is by doing an oil analysis. Like I said before, I did oil analysis on my chevy truck's engine for about three years and had around 7 analysis done during that time period and the 5W-30 Mobil 1 I was using was less than impressive considering the cost for the oil. My wear #'s were better with regular conventional Chevron and Havoline. I also had more engine noise and oil consumption using Mobil 1. Too many people go by the fancy marketing that these oil companies put out instead of actually testing the oil in their particular vehicle.

During that time period I was also using 10W-30 Mobil 1 in my ex-wife's 98 Grand Prix with the regular 3800 and there again, I had better oil analysis results using conventional oil.

Unless the manufacturer specifically states that I have to use a synthetic, in most cases I won't.

Wayne

 

Yeah, I honestly wouldn't stress about it too much. My Regal GS owners' manual doesn't mandate the use of synthentic oil and it's got the same L67. My L36 doesn't either, and it's got the same oiling system, block, and in the bottom end all but the pistons are the same as the L67. The trend among auto manufacturers is to recommender "thinner" oils that produce better gas mileage and lower emissions.

I personally use synthetics...mainly because of the extra 1-3 horsepower you'll see with them. Yes, I am that crazy. LOL

 

As far as I know, ALL GM cars that REQUIRE a full synthetic oil are factory filled with Mobil 1 synthetic. And these cars come from the factory with the Mobil 1 oil caps...

Unless they changed the oil spec for the L67 in later years to synthetic, my grandma's 99 Buick Regal GS with the 3800 series II Supercharged V6 does NOT require synthetic oils. She gets her oil changed at a GM dealer everytime, and they do NOT put synthetics in it, they always do the standard 29.95 oil change.

Like I've said before, I HIGHLY recommend the use of synthetics in ANY car. I have always, and will always use them in all of my cars.

 

I just checked my owner's manual and it doesn't say anything about using an oil that meets GM4718M requirements. They said to use an oil that meets the GM6094M requirements. The only mention about using synthetics is if you live in an extremely cold climate and that a 5W-30 synthetic oil will allow the vehicle to start easier and offer greater protection.

I may try a synthetic again in the future but it won't be Mobil 1 even though it seems to be everyone's favorite.

Wayne

 

i am going to say some thing if you started your car off with synthetic for the majority of its life just becarefull do to how slick synthetic is compared to conventional you can feel the difference between the two on your fingers. also if you have anouther car that you drive as well and have the other car sit synthetic will be better do to how fast it gets to the top and all the moving internals. i have my mustang sit at least three weeks out of the month and 0w-20 synthetic helps out alot do to dry start up.thats what i am saying it gets every where faster if you have another vehicle to trade up with. it gives a little added protection just my opinion. remember its my opinion so pleas dont rip my head off