Mobil One Oil in older engine?

[Gary N.]

I recently read the information about the ZDDP and CJ-4 concerning oil for vintage corvettes (particularly from Duke Williams) . I recently put Mobil One in one of my older engines (before reading the above information) to see how it worked and was wondering if it will do any harm to it. The engine has hydrolic lifters and is not new. Is it Ok to run this oil or should I change it out and go back to an oil with CJ-04 in it.
Thanks,
Gary

[Robert C.]

Re: Mobil One Oil in older engine?

According to Mobil, Mobil 1 is great for older engines. They almost garanteed me that all wear on the internal parts would halt at first use of the product.

[Jack C.]

Re: Mobil One Oil in older engine?

Have been using it in my 71 LT1, 68 427/400. No problems.

[Chuck S.]

Re: Mobil One Oil in older engine?

You're trying to get Duke fired up on this Sunday morning, aren't you? HaHaHa...

Duke is no respecter of synthetic oils. Even for modern engines, his position is that synthetic oil offers no advantage over mineral oil regards lubricity. Further, synthetic is not cost advantageous....it costs more for little to no advantage, marketing hype not withstanding. Duke also believes brand is unimportant...in other words, unlike parts, OIL IS OIL in accordance with it's API service label seal.

From an engineering perspective, Duke is correct...but I just can't bring myself to use anything but Mobil 1 in my C6, and a major refiner's brand mineral oil in my other cars. Sorry, Duke...it's like taking that first step out of the perfectly good airplane door; I don't have enough faith to let my technical training interfere with my personal maintenance habits.

As a completely separate issue, Duke recommends CJ4 (an API service classification, not an additive) for our classic engines BECAUSE of the ZDDP additive that is in CJ4. The ZDDP level in motor oil has been reduced over the years to prevent catalytic convertor poisoning just as unleaded gasoline was required. OTR trucks don't have catalytic convertors, so they can use motor oil with higher ZDDP additive level to reduce startup and operation wear. The CJ4 service classification is actually closer to the oil these engines were designed to run.

Based on Duke's recommendation, I have used CJ4 in my old 80s vintage beater truck which is closer to a classic Chevy than my C6. In your place, I would probably switch to CJ4 oil at the next change. It's not a high urgency, but over a lifetime of changes, your engine will probably experience a little less wear with the CJ4 oil...and your wallet will have a little more "folding money" in it.

[Mark R.]

Re: Mobil One Oil in older engine?

Gary:

About 8 years ago, I acquired a 1970 Corvette with 14,000 miles. I removed the oil and started using Mobil 1 and have done so ever since. Absolutely no problem and thankfully no leaks.

Mark

[Duke W.]

Re: Mobil One Oil in older engine?

Mobil 1 carries an API service category of SM, so it is not the best choice for vintage vehicles as I have discussed many times, before, and if you do some searching you will find Web links to educate yourself on all the whys and wherefores. There will be an article on the subject in the next issue of The Corvette Restorer.

The best oil for vintage engines is CJ-4, and no supplemental additives are required.

GM has a specific oil specification for modern Corvettes, which Mobil 1 meets, so that's what I'd use in a modern Corvette if I owned one.

"Synthetic" is just a marketing term. Oils that are advertised as "synthetic" are blended from API Group II and Group III base stocks rather than primarily Group I with some added Group II or III, and they have greater oxidation resistance so they can be run for extended drain intervals when used in conjuntion with an oil quality monitoring system like modern Corvettes have.

If you insist on "synthetic" use CJ-4 in the 5W-40 grade, but unless you are driving more than 5-7K miles between changes or commonly do cold starts below 15 degrees F, I think it's a waste of money.

SM is designed for modern engines, and that's what I would use in a modern engine, but I recommend CJ-4 for vintage engines, and CJ-4 is what my vintage engines get. The "newest" is model year 1991.

I'll define "vintage" as any engine that has flat tappet cam(s) and plain bearing rocker arms if rocker arms are part of the valvetrain design. If the engine has "roller everything" in the valvetrain, SM is okay.

Duke

[Brian G.]

Re: Mobil One Oil in older engine?

Make sure you read the label carefully.

I just noticed I bought Cl-4 Delo 400 instead of CJ-4.

[Joe L.]

Re: Mobil One Oil in older engine?

Make sure you read the label carefully.

I just noticed I bought Cl-4 Delo 400 instead of CJ-4.

Brian-----


For your application, the CI is as good or better than the CJ.

[Duke W.]

Re: Mobil One Oil in older engine?

There is not enough technical difference between CI-4 and CJ-4 to justify a preference in a vintage spark ignition engine based on any rational technical argument.

If you have off road diesel equipment that uses high sulphur fuel, there is a preference for CI-4, but we're not talking about this application.

As time progresses CI-4 will become less common in typical auto parts outlets. If faced with a choice of either, I buy the least expensive.

Duke

[Clem Z.]

Re: Mobil One Oil in older engine?

to get around dukes idea that mobil 1 cost too much i drain the mobil 1 from my new corvettes once a year,about 4/5 K miles and put it in my 88 silverado pickup which has 150,000 + miles for another 4/8K miles. oil does not were out and sure does not get dirty in my new corvettes. i used to put new mobil 1 in the truck but the oil coming out of the corvette is almost new so why throw it away

[Edward S.]

Re: Mobil One Oil in older engine?

I bought a new Avalanche at the same time that I had a c5 convertable, being the non-machanic I am, I just figured if Mobil I was good enough for the c5 it had to be good for the Avalanche. I replaced the break in oil with Mobil I after about a year and a half the truck started to look like a crop duster plane. My mechanic showed me how my seals were eaten away, we put new seals in and went back to the original oil and never had the problem again. In reading the hits already on this question, it seems this problem was only with the Avalanche. If you ever see me with a wrench in my hand it's only because I'm trying to sell it.

[Clem Z.]

Re: Mobil One Oil in older engine?

I bought a new Avalanche at the same time that I had a c5 convertable, being the non-machanic I am, I just figured if Mobil I was good enough for the c5 it had to be good for the Avalanche. I replaced the break in oil with Mobil I after about a year and a half the truck started to look like a crop duster plane. My mechanic showed me how my seals were eaten away, we put new seals in and went back to the original oil and never had the problem again. In reading the hits already on this question, it seems this problem was only with the Avalanche. If you ever see me with a wrench in my hand it's only because I'm trying to sell it.

i have used mobil 1 in the silverado since new in 1988 and after i got back into corvettes in 97 i said why waste expensive oil with only a few miles on it. the truck runs great and the engine is actually quieter than my 2008 C-6.

[William F.]

Re: Mobil One Oil in older engine?

Duke,
Just asking, where do you get your oil expertise. You can read anything on "the internet", lot of it BS. What do oil company experts-engineers say about oil for vintage V8's.
Thanks,
Bill Ford

[Patrick T.]

Re: Mobil One Oil in older engine?

There is a sticker on the oil filler cap of Z06's that states if you don't use Mobil One in the car, the warranty is voided. PT

[Duke W.]

Re: Mobil One Oil in older engine?

How do I summarize a lifetime of education and experience?

Starting with my late father who was an automotive engineer, who first taught me about API engine oil service categories as a teenager in the late fifties (He was an early user of the first "heavy duty" oils that were the first to include significant detergent additives in his 1949 Cadillac Fleetwood 60-Special with its new OHV/hydraulic lifter valve train engine.), I received a BSME from the Universtiy of Washington (where I took my first bearings and lubrication course) and a MSME from the University of Wisconsin Engine Research Center, then spent my career in the auto, aerospace, and computer industries.

From my dad first exposing me to API engine and gear oil service categories, including the Mil-L-2105 hypoid gear oil that was developed for military vehicles and used by the auto industry (and referenced in the 1963 Corvette Shop Manual) since he was an Army vehicle service engineer during WW II, I have followed their progress including changes in base oils and additives ever since.

What all of the above taught me is to seek out authoritative information/documents on any technical subject, and with the Internet it's as easy as shooting fish in a barrel. I have referenced all engine oil related source documents that I use in both written articles and online posts - documents such as API 1509, which is the primary document used by the entire auto and oil industry to blend and test engine oils to manufacturers' requirments for new vehicles, and anyone can download this document off the Web and read it.

From there it's a matter of understanding the requirements for different engine architectures (such as sliding versus rolling valvetrain wear surfaces), the history of engine oil formulation, and making an informed decision on what currently available API service categories are best for vintage engines.

SM oil, which is formulated for modern "roller everything" engines with catalytic converters will probably do no harm on a well broken in OE engine, but for the same price the better additive package (including more anti-wear additive) of C-category oils provides additional anti-wear insurance for vintage engines with sliding surface valvetrains and there is no concern that any additive will degrade catalysts.

To me the decision is a no-brainer!

To newer members who did not receive last summer's "The Corvette Restorer" with my engine oil article, it was republished in another club's online magazine. The oil article starts on Page 3.

http://www.westcoastwillys.com/WCW_Sept08_small.pdf

Duke