rotella T better than valvolene?

[PILOON]

Diesel Power

I read a long, well documented discussion on a web site (now forgoten) about EPA changes to additives in oils.
The author related to negative results due to these changes.
His reserch (well sourced and quoted) sumarized that in reality one was better off to use diesel rated oils in their autos.

He had restored at great expense a british sports car that ended up chewing out the camshaft in the first 1000 miles and this led to his research into the causes.

His contacts with the rebuilders and oil companies (even major auto manufacrurers) supported his comments.
I seem to recall that the moly had been dropped in most formulas and this was the cause of his 'fast wear'.
He was told by a few major (names forgotten) OH shops that diesel rated oils now best met breakin oil requirements .
One car manufacturer admitted to him that even they experienced unusual wear carteristics and as a result urged only the usage of their own brand of oil.

After reading his long discussion I decided that from now on my car gets diesel rated oils only and reading some of your posts (phew, between oil, grease and fuel--its a lot to retain) you give me the impression that I am on the right track.

Can you comment?
Thanks.

 

[DieselPower]

This is mainly only true in older "flat tappet" cam engines. The majority of new gas engines these day's are roller tappet cam engines. The problem with older flat tappet and especially high lift cam's or performance engines is that the zinc (ZDDP) level of gas engine oils have been greatly reduced and premature cam failure seems to be a growing problem. Diesel engine oils tend to have greater levels of ZDDP in them and is the reason many people use diesel engine oil in their vintage cars and performance engines. The contact area between the cam and the lifter in flat tappet cam engines is under greater extreme preasure than roller lifter engines. Zinc is a wonderful additive that provides great extreme preasure protection and is very cheap. The problem is that zinc tends to over the life of a vehicle plug up catalytic converters hence it's additive level in gas engine oils has been geatly reduced in recent years.

On the bright side many new engine oils are starting to use more modern additive technology to combat the effect of reduced extreme preasure protection due to reduced levels of zinc. Many of the new oil standards for gasoline rated oils like ILSAC GF-4 and the upcoming GF-5 rating's test for these properties in oil.

My personal suggestion to someone looking for a engine oil for their gasoline engine is to either buy a gas rated oil that is API SM and ILSAC GF-4 rated or as you do use a diesel engine oil. The problem with using diesel engine oil is that there are very few viscosity's to pick from namely 10W/30 and 15W/40 in conventional and 5W/30 and 5W/40 in synthetic.

 

[DieselPower]

I forgot to post a link that explains what INTERNATIONAL LUBRICANT STANDARDIZATION AND APPROVAL COMMITTEE (ILSAC) GF-4 is. http://www.ilma.org/resources/ilsac_finalstd011404.pdf

 

[SkyPup]

We always use the same Group IV synthetic diesel engine oil that we use in all our tractors in all our gasoline engines too.

 

[KICK]

"Well sir after owning the service stations I found there are three thing you do not discuss, 1.) religion 2.) politics and 3.) the type and kind of oil used in a vehicle." His reasoning and theory being everyone has a different opinion and what you were using would be wrong. I never did find what kind of oil he was using.

aint that the truth.