[DE Dubber]

I wanted to ask a few questions in the "which oil should I use debate".

Are the synthetic oils developed for use in diesel engines a good choice in gas powered cars?

Oils such as Mobil Delvac 1, Shell Rotella T, Valvoline Premium Blue are all 5W-40 but were developed for diesels. I know they have special formulation to handle the soot that diesels produce.

What are the opinions here?

 

[Macabre]

http://www.mobil1.com/products/faq.jsp?catId=20

Q:
Mobil 1 with SuperSyn™ is an API CF oil and Mobil Delvac 1® is an API SH oil. Since I have both a gasoline and a diesel engine, which is better?

A:
Gasoline and diesel engine oils are formulated differently, but they do have some cross application. This is particularly useful for fleet operations that have a variety of engines. Being able to use one motor oil helps reduce inventory and eliminate misapplication mistakes. But we do not attempt to compare Mobil Delvac 1 to Mobil 1 with SuperSyn™, since they are primarily formulated for different applications.

For consumer use, we suggest that you should be guided by your primary application in deciding which synthetic motor oil to use. And keep in mind that some diesel engine oils now call for CE, CF-4, CG-4, CH-4 or CI-4 – which requires the use of Mobil Delvac 1 or Mobil Delvac® 1300 Super.

Whether you have a gasoline or a diesel engine, the owner's manual is the best place to look to determine what oil you should use – but you need to get two pieces of information:


The viscosity grade, and
The API service category (API SL, SJ, SH/CF, CD, etc.)

 

[Msquared]

FWIW, I'm now running Schaeffer 15w40, which is also formulated for diesel use. However, it's a relatively low-ash formula (unlike some diesel oil) and has a killer additive package (killer in a good way, that is!). It's called a blend, but it's a blend of really good Group II oil with Group IV true synthetics (unlike most synthetics which use Group III oils instead of IV). The specs for it are better than most Group III synths you can buy (maybe all of them). The results from some analyses from my friend's Jetta have been very promising. Best of all, this stuff is about $2.50/qt when purchased in quantity, so it's way cheaper than a lot inferior oils. Anyway, this is all said in support of the fact that it is possible to run diesel-formulated oils and get good results for less money than the $5/qt synths on the shelf in your local parts store. I'm kind of assuming that's your goal.

Also FWIW, I would say if you're going to pay $5/qt and want to get oil quickly and locall, go with Mobil 1 0w40. It's a true Group IV synth (which makes the price a lot more justifiable than the Group III junk), has good specs, and actually has the VW certifications. It's substantially different (for the better) than the other Mobil 1 weights available in the US, and I believe it's even factory fill in some high-end German cars. It's really good stuff and you can't go wrong with it. Combine it with a good filter, and you could actually move to 10k-mile change intervals, thereby cutting the costs in half (I wouldn't do that with the other commonly-available "synths" on the shelf).

 

[jpsmith]

Is there any possibility of getting into a warranty denial problem by using 0W-40, since it is not mentioned as a "recommended" weight in any of the VW documentation (that I'm aware of)? I know Mobil 1 is great stuff, and I'm inclined to go with it when the time comes....I just wonder why VW hasn't explicitly stated anywhere that 0W-40 is OK.

 

[Msquared]

Is there any possibility of getting into a warranty denial problem by using 0W-40, since it is not mentioned as a "recommended" weight in any of the VW documentation (that I'm aware of)? I know Mobil 1 is great stuff, and I'm inclined to go with it when the time comes....I just wonder why VW hasn't explicitly stated anywhere that 0W-40 is OK.

It most definitely is recommended. It has the VW 501 (or whatever the # is) rating, which is sufficient according to the manual.

 

[B12Teuton]

I am running the Shell Rotella T Synth. Very happy with it and you can't beat the price at $12.89/gallon at Wal-Mart.

I know it was desigend with diesels in mind, and it does mention this (only on the back of the jug), but it also says it is approved for all gas engines as well.

Main reason I started puting it in my cars was actually because the Rotella line is very popular amongst motorcyclists. I had it in my bike first!

Also, I figued since most diesels are turbo's, the 1.8T would probably be happy with it.... and it is! :thumbup:

 

[Msquared]

I am running the Shell Rotella T Synth. Very happy with it and you can't beat the price at $12.89/gallon at Wal-Mart.

I know it was desigend with diesels in mind, and it does mention this (only on the back of the jug), but it also says it is approved for all gas engines as well.

Main reason I started puting it in my cars was actually because the Rotella line is very popular amongst motorcyclists. I had it in my bike first!

Also, I figued since most diesels are turbo's, the 1.8T would probably be happy with it.... and it is! :thumbup:

Just FYI, bikes have pretty different requirements. For instance, they have wet clutches, so you don't want to put Schaeffer with moly in them or the clutch will slip. There are some other things too, which I have forgotten. It doesn't mean a bike-friendly oil won't work well in car, but the fact that an oil is good for bikes also doesn't mean it will be good in a car. Check the specs on Rotella, but I think the big think about it and some other diesel formulations is the high ash content. I think that can affect emmissions control equipment, but now that diesels are having to use EGR the oils may get lower in ash content. So I would predict that eventually the two formulations are going to get closer in specs.

 

[x]

The cross application seems to be more direct for diesels and petrol with turbos, than n/a engines.

 

[B12Teuton]

Just FYI, bikes have pretty different requirements. For instance, they have wet clutches, so you don't want to put Schaeffer with moly in them or the clutch will slip. There are some other things too, which I have forgotten. It doesn't mean a bike-friendly oil won't work well in car, but the fact that an oil is good for bikes also doesn't mean it will be good in a car. Check the specs on Rotella, but I think the big think about it and some other diesel formulations is the high ash content. I think that can affect emmissions control equipment, but now that diesels are having to use EGR the oils may get lower in ash content. So I would predict that eventually the two formulations are going to get closer in specs.

Not all bikes have wet clutches. See any Ducati, for example.
Bikes also share the engine oil with the tranny. Thus a bikes oil requirements are somewhat higher than a cars. Not to mention that most run at higher temperatures and under much rougher conditions due to the 14000+ rpm that some modern bikes turn. :weirdo:
I can only speak to the Rotella, not the Schaffer product. It does have higher detergent formulation than some regular oils.

 

[mghunt]

I've also thought about using the Rotella T in my Passat. I have to buy the stuff for my wife's TDI every time I do a change for her car and it is much cheaper than 4 quarts of Valvoline 5W-40. Can using the Rotella T, or Delvac Syn hurt our cars. It seems that there's a lot of speculation one way or the other, however, does anyone really know for sure? The TDI guys swear by both.

-Mark