what is the Best Oil to use?

[Booie]

In a stock 1979 L-48 350 cu in what oil do you recomend using in it Regular oil, full Snythetic or snythenic blend and why.I just bought the car last july and was going to change the oil and filter and got to wondering what is the best to use. :confused

 

[minifridge1138]

I used Synthetic when I bought my car. It worked very well (the engine was very clean and well lubricated when i replaced the intake manifold and timing chain). However, I always found large puddles of oil under the car.

I switched to Castrol GTX High Mileage and my oil leaks have almost disappeared.

The molecules of synthetic oil are smaller than "dino" oil. That means they can lubricate in tighter spaces, but can also leak a lot easier.

Good Luck!

 

[Yoda]

This question has been asked many times over all the Generations of Corvettes here at the Action Center. Even some spirited debate about "dino" verse's "synthetic".

I've never entered into the discussion, I'm not well versed in this subject, but I'll toss my .25 in here ... just because

When Rare came out (1981) the factory/GM recommended "dino" oil! So I run Castrol GTX 10~30 and NAPA Oil Filter. Since I change oil maybe twice a year, sometimes three times on a really active year and average around 5,000 to 9,000 a year depending upon where CruiseFest is :L and where I'm living at the time

Now on Abby it's a different story (2003). I use Castrol Syntec 5~50, here again the factory/GM recommends Synthetic Oil.

I change my own oil in all my vehicle, well so long as I can get my big arse down there and drag it back upright, I'll continue to change my own oil

Bud

 

[Vettehead Mikey]

If you're looking for hard facts instead of opinions, best do your own research.

Ignore the posts that state 'I switched from type X to type Y three weeks ago and it didn't blow up yet so that proves that type Y is better'.

Beware of advertising marketing claims that make vague statements so wishy washy that you couldn't sue the manufacturer. New! Improved! Helps mileage!

Ignore the seat of the pants claims stating the car did this or that better with the new oil. Unless it's a blind A-B test then it's not subjective. The owner is usually allowing emotions rule in an attempt to justify the investment.

Beware people that transpose irrelevant observations to prove an unrelated point. 'My type Y oil is a prettier shade of brown, that shows that global warming is not just a myth'

If it's long term durability you're asking about (for example), find out how long engines tend to last on oil type X, and how long on oil type Y. Make sure it's a large sample to lessen the effects of one off aberrations, either good or bad.

If you apply these methods to the typical SBC you'll get a big surprise- the lubrication system is not the weak link, irrespective of what type of oil had been used over it's lifespan. IOW- Engines typically get junked or overhauled due to causes other than bearing failure or wear. Operator abuse is the #1 killer BTW. Using oil type X or Y will not cure stupidity. If you think you've really got a 710 cap on your car, best stop reading now.

Those that do make past those non-related type of failure have 150K, 200K 250K miles on them. Trying to find evidence that there were more engines in a group that always used type X oil vs. type Y oil (which might indicate which was better for durability) is just not there. I've been looking for almost 20 years and have yet to see enough evidence to draw a conclusion.

Consider also that the average driver of an older Corvette puts very few miles on it per annum and that it's likely that the average miles per annum will decrease as the years go by. Most C2/C3 cars put less than 5K miles per year, some less than 500 per year.

If an engine will typically go 150K miles even using 'cra*p' oil (lowest common denominator), then the predicted life span would range from 30 to 300 years.

In my case, I've predicted my calendar TBO is in the range of 70-90 years from now. I'll just leave a note on the dashboard to tell my inheritors to be very conservative, and to do a precautionary overhaul in 2070.

 

[bill81vette]

My preference is Castrol GTX as well,
but I like the 10W-40,my own preference...

 

[fine69]

I prefer Wesson.... Are we really gonna have this discussion AGAIN???...




Geez!

 

[LT4man]

I use BMW oil in my engine and my trans!

No fooling! otfl otfl otfl

Those of you who really want to know what BMW oil, send me a pm.

SAVE THE

 

[Booie]

Well thanks for all your input I too always change my own oil and filters. But you hear so many claims on what one oil will and won't do I really don't put alot of miles on any vehicle I've owned and I pretty much change the oil by months than miles. But some mechanics at the place i work at said don't bother with synthenic that it is thinner and it might start leaking from an older engine. Just keep it fresh an use a good filter and don't keep switching brands. So I'll just keep it fresh.

 

[Yoda]

I prefer Wesson.... Are we really gonna have this discussion AGAIN???...




Geez!

How often do you change your "Wesson Oil" ????

Even thou this topic has been discussed many times around here, it is a question a member has that seeks an answer... Oh yea we could point them to the Search Feature, revisit the subject, iqnore the question or worst case, turn the question into .... nevermind....

Bud Dougherty
Amarillo, TX

 

[fine69]

How often do you change your "Wesson Oil" ????

Even thou this topic has been discussed many times around here, it is a question a member has that seeks an answer... Oh yea we could point them to the Search Feature, revisit the subject, iqnore the question or worst case, turn the question into .... nevermind....

Bud Dougherty
Amarillo, TX

You are right. My apologies.... long long week it's been.

After my rebuild, I used Valvoline oil that contains zinc to ensure proper camshaft break-in. I've stuck with that oil along with a regular GM filter... no problems.

Ralph

 

[Vette79]

For an older car running a flat tappet cam the oil should contain a significant amount of ZDDP. If it does not then you can purchase ZDDPlus at motors.ebay.com.

 

[fine69]

For an older car running a flat tappet cam the oil should contain a significant amount of ZDDP. If it does not then you can purchase ZDDPlus at motors.ebay.com.

FYI for those who are unsure, ZDDP stands for "zinc dithiophosphate" (i.e., zinc).

 

[TedC]

A friend of mine is a chemical engineer in Mobil's oil research lab had a very simple and honest response when I asked him what oil he uses in his cars? "Use the type and viscosity the manufacture recommends. Use a filter with proper flow rates, fill it before use if possible, and change oil between 3-6 months once activated, regardless of BRAND or TYPE. Additive activation process or clock starts the first time you run the engine with the new oil."

 

[svntyone]

My two cents are that in addition to the consideration of lubrication, is temperature, and the rated abilities of dino and synthetic to not only resist breakdown, but transfer heat. From what the literature seems to say, synthetic is superior in both areas. These were the primary consideration points for me when I made the move from dino to synthetic. As Vettehead Mikey states - do your homework and you'll make an informed choice.

 

[red70vette]

What you use and how well it works depends on how you use the car. I drive mine about 3,000 miles a year and usually park it for 4 months in the winter. I change my oil before storage every year and use Castrol 20W/50.

I don't use synthetic because I change oil too often, and because I heard that synthetic could cause leaks in older cars because it seeps past old seals. I have no proof of that but I heard that somewhere. By changing oil every year at about 3000 miles I see no point in using synthetic and paying a premium for longevity.

 

[BruceBed]

A friend of mine is a chemical engineer in Mobil's oil research lab had a very simple and honest response when I asked him what oil he uses in his cars? "Use the type and viscosity the manufacture recommends. Use a filter with proper flow rates, fill it before use if possible, and change oil between 3-6 months once activated, regardless of BRAND or TYPE. Additive activation process or clock starts the first time you run the engine with the new oil."

There you go. End of discussion.

 

[vett boy]

There you go. End of discussion.

Yep

 

[Phill]

I usually use whatever brand name oil is on special at the time. but now ive heard of the zinc thing a few times so ill be looking for a brand oil with zinc or ZDDP next time i change the oil.

 

[Booie]

Thanks everyone I just changed with Regular Oil Castrol 10W/40 and A fresh filter like I siad I just bought it last year and aslo plan on about 2-3000 miles. A mechanic at work also said the same thing about synthetic oil in an older car so why start leaks when you don't have them.