Shell Rotella oil

[Gary N.]

Well now I'm confused! I have used Shell Rotella T-4 oil in my 66 Corvette and other older flat tappet engines for many years just as many of you probably have also used it because if contains ZZDP needed for our older engines. I just finished reading an article that I saw from Motor Trend giving reason to not use this type of oil in a gasoline engine. I am posting this article to see if any of you would like to comment of it's information.

https://www.motortrend.com/how-to/diesel-oil-in-gasoline-engine/

[Mark E.]

Re: Shell Rotella oil

Interesting food for thought, Gary. There's so much contradictory information out there about using diesel oil in flat tappet engines.

I've used Mobil 1 15w-50 the past 15 years or so. It has 1,200 ppm P and 1,300 ppm Zn, and is formulated by a major oil company for flat tappet spark engines so I consider it a safe choice. Walmart sells it for less than $25 for 5 quarts so it's affordable too.

[William F.]

Re: Shell Rotella oil

Who wrote this article? What are his qualifications? Article mainly refers to "hot rod" and racing engines. In most instances this is different from our older collector Corvettes. I started using diesel oils in 1999 when I read an article in Car and Driver (Nov 1999 p 23 "Searching for the right motor oil for "keeper cars.", author Ed Kollin, former research chemist over engine test lab at EXXON) who recommended diesel oil for our flat tappet engines. One of his main points was that diesel oils will cling longer to the engine's parts which is important for cars that may not driven for several months, in addition to the value of ZDDP content.

[Harry S.]

Re: Shell Rotella oil

Just bought 10 quarts of T4 to change the oil for the winter, I'll continue using it. The 63's have enjoyed it for the last 25 years.

[Joseph S.]

Re: Shell Rotella oil

Lucas and Joe Gibbs both make an oil specifically for Flat tappet engines. I've never used Rotella in any Classic Cars.

[Ed S.]

Re: Shell Rotella oil

Does Shell run Rotella ads in Motor Trend? Probably not. Do other "racing brand oil" products advertise in Motor Trend - probably. Ya gotta consider everything these days...... it is a cruel world out there.

[Ed S.]

Re: Shell Rotella oil

The article was written by Lake Speed Jr. Take a moment to check out who he works for - Joe Gibbs Racing for one and "Driven Racing Oil". Ya can't blame the guy for promoting his own product or those of the companies that is paying his salary but.........

[Jeffrey S.]

Re: Shell Rotella oil

Duke Williams has posted on this MANY times and has advised that Rotella or any other "C" (CJ, CK) rated oil is absolutely fine for our cars. Until he says otherwise I will continue to use it or, as he has suggested, whatever the cheapest "C" oil I can find.
Jeff

[Bruce G.]

Re: Shell Rotella oil

Duke Williams has posted on this MANY times and has advised that Rotella or any other "C" (CJ, CK) rated oil is absolutely fine for our cars. Until he says otherwise I will continue to use it or, as he has suggested, whatever the cheapest "C" oil I can find.
Jeff

Which according to Duke was Walmart Super Tech 15/40W. Bruce

[Duke W.]

Re: Shell Rotella oil

The current MINIMUM P level for S-category oil is 600 ppm and the max is 800.

I'm not aware of a minimum P concentration for C-category engine oil, but the current max for CK-4 is 1200 ppm.

Most major brands have spec sheets on the Web that list chemical composition including P. Some now have way less than the 1200 ppm max because they are incorporating new Boron-base additives, most of which are proprietary and patented.

Unfortunately none of the spec sheets that I know of list the B concentration, but the important thing to remember is that the C-category test suite has tougher anti-wear tests than S-category and ZDDP is not the only way to clear the hurdle.


Fromer NASCAR driver Lake Speed claims he is a "Certified Lubrication Expert", a title I'm not familiar with, but the fact that he is associated with an organization that markets "boutique" engine oil products to the vintage car community raises a little suspicion.

Duke

[Duke W.]

Re: Shell Rotella oil

The current API spec for CI engines is CK-4. There are numerous Multi Grade CK oils that are also spec SM for Spark Ignition engines.
The allowable maximum of Phosphorus for SM is 600 ppm. The minimum allowable Phosphorus for CK is 1000ppm. See the problem? Many of these dual-spec oils have Phosphorus in the 800 range. Not enough for older diesel engines, and too much for catalyst health in gassers.

There are CK-4 oils with no "SM" spec. Phosphorus is generally 1000ppm. So if you're purchasing multi-grade "Diesel Oil" look for CK-4 only. Not CK-4/SM.

The important thing is to buy a product with CK-4 as the FIRST listed category. Secondary categories are OPTIONAL, so CK-4 is no different from CK-4/SN.

I don't know where you guys come up with all this stuff. It's all explained in my oil article. Some of you need a refresher and if you've never read it...

Duke

[William F.]

Re: Shell Rotella oil

A strange, high viscosity. Original manuals recommeded 10w30 and maybe just 30 for extreme conditions.

[William F.]

Re: Shell Rotella oil

Lake is from my state, MISSISSIPPI. He raced in NASCAR for a while back in the sixties but never had consistent success.

[Duke W.]

Re: Shell Rotella oil

Which according to Duke was Walmart Super Tech 15/40W. Bruce

You guys are driving me nuts.

My basic recommendation is to buy an engine oil where the first listed category is a current or past (but not obsolete) C-category, currently CK-4.

BRAND MAKES NO DIFFERENCE!!!

I usually buy engine oil at Walmart and they usually stock the three national brand C-category products and their own SuperTech house brand C-category. I always buy the least expensive, which is usually the house brand, but very occasionally one of the national brands might be less expensive, so I buy that.

Is that so hard to understand?

Duke

[Christopher R.]

Re: Shell Rotella oil

You guys are driving me nuts.

My basic recommendation is to buy an engine oil where the first listed category is a current or past (but not obsolete) C-category, currently CK-4.

BRAND MAKES NO DIFFERENCE!!!

I usually buy engine oil at Walmart and they usually stock the three national brand C-category products and their own SuperTech house brand C-category. I always buy the least expensive, which is usually the house brand, but very occasionally one of the national brands might be less expensive, so I buy that.

Is that so hard to understand?

Duke

I agree. But I've got a curious thing going on now. I have a new Suzuki 4 stroke outboard motor. Everyone I talk to insists that I can only use Suzuki's Ecstar V7000 10W-40 semi-synthetic motor oil. It carries an API "SJ" classification. I've spoken to my dealer and a few aftermarket suppliers (because it's hard to find). They all insist that Mercury oil is different from Yamaha oil which is different from Suzuki oil. When I tell them that it's all the same, they look at me in horror. The motor is under warranty, so I'll keep looking for the Suzuki brand. I originally thought that my dealer believed this because he sold the product. But he carries Mercury, Yamaha, and Suzuki oils. Then when I called other places, they all said the same thing. These guys may be wrong, but I am convinced that they are sincere.