High Mile Oil Recommendation

[turbo78vair]

We bought our high mile (162k) '78 pace car earlier this year. We know very little about the vehicle history. Hopefully we'll get to see some invoices dealing with mechicanical work done in '03 in the next month or so.
My question is in regard to what grade oil to use. I changed the oil after we got it back in the spring. I put the new high mile oil in it - believe it was Quaker State. In the approx 1200 miles that we put on it over the summer, I added part of a quart. It does have a few drips. It does not smoke.
For my fall oil change, Im thinking about staying with same high mile 10w30. Ok to stay the same or should I think about maybe 20w50 for use with suspected higher internal engine clearances from the higher miles?
Thanks Gary C '78 L48

[Vettehead Mikey]

At the risk of being called a Luddite again, stick with ordinary 10W30 or whatever your owners manual calls for.

If you've gone 162K miles and it doesn't smoke, hardly uses any oil,barely leaks and (I assume) has acceptable oil pressure, you're trying to fix something that's just not broken. You do not want thicker oil for cold weather!

I wish I had your engine in my car.

[6880 Mike]

Originally Posted by Vettehead Mikey

...stick with ordinary 10W30 or whatever your owners manual calls for...

I agree.
What, exactly, are supposed to be the advantages of the high mileage oil? Older smallblocks run for eons and zillions of miles on regular dino oil.

[Culprit]

I agree - use whatever the owner's manual calls for. That's what I do for all my vehicles.

I have a 95 Ford Ranger with 204,000. I've never used anything other than the cheap Wal-Mart or Pep-Boys brand 5W-30, and a good phram filter.

Change it every 3000 and leave it alone.

Oil, is oil, is oil. If it meets the engineering spec (as all brands on the market do) then there is no need to pay higher prices for fancy brand name oils. In fact, those fancy oils are more likely to have detergents and other additives in them that are not supposed to be in your engine. Just pick something and use the same thing every time - don't change weights/brands every time you change the oil.

[Nut]

I switched to Synthetic around 100K miles. She has 250K+ now and has never been rebuilt in any way and only a slight puff on start up after she sits for 2-3 weeks (which valve seal wear). But then again I have religiously changed the oil, filter and air filter every couple months regardess of how many miles driven.

......... nut

[srs244]

i realize that this is going to be contrary to every opiniuon previously expressed, BUT........ today's engine oil composition isn't the same as the oil formula of the "old" days. there is a school of thought (that personally i agree with only because it seems to make sense to me) that modern oil designed for diesel powered cars contain many if not all of the characteristics of the oils used 20-30 years ago (apparently additives that have been removed from your basic 10w-30w type oil). if you do a search here, you should be able to find quite a lengthy discussion on the subject. if i remember correctly it was about 6 months ago or so. mine is just another opinion, however.

[Jack]

I like the "diesel truck oil" for our engines. Shell Rotella T 15W-40 or Mobil Delvac 1300 15W-40. Either have wear additive packages quite similar to what was normal when our C3's were new; wear packs that have nearly disappeared from today's typical passenger car oil formulations. Either are widely available & inexpensive. Either are certified for use with both diesel AND GAS engines.

[turbo78vair]

I think that I have 3 qts of Cummins Premium Blue 15W40 sitting out in the barn. I've only had them for about 20 years or so. Don't think I'll put them in the Vette. Many years ago, I ran this oil in our late 70s and early 80 cars. I always had very satisfactory results. These 3 single quarts of oil have moved from Indiana to NY and back again to Indiana. Still on the shelf!

Based on your input, I'll do some checking to bring myself up to date on today's 15W40.

Thanks for your comments.
Gary C - '78 Pace Car L48

[vett boy]

My 69 went 286000 miles (one engine rebuild) All I ever used was 10/30 .The fellow who ownes it today is doing the same thing.I'd find one brand one grade and stick with it.QS formula is not the same as Tex,mobil,shell etc