Diesel engine oil

[SSteve]

Is it OK to "top-up" the oil level on our CAT C7 with a brand of oil other than what went in it at the last service? Its a given that the type (dino or syn) and viscosity will be the same.

We full-time and it occurred to us that each future service could find us with a different brand of oil and will be left with the choice of either buying some of the "new" brand to top-up and discarding the old, or just use what's left of the old.

Any advice?

Thanks,
Steve

[Nick-B]

Oil questions usually get you a whole myriad of "opinions" on the subject. So here is my "opinion".

Top up with what ever you have or can get. The preference would be a diesel rated oil, like Chevron Delo 400 or Shell Rotella and something like those should be used for a complete change, but to just top up - whatever you got will work fine in a pinch.

[ninos]

I say use what ever you can get, but If you have syntetic don't mix with regular use regular with regular and syntetic with syntetic the brand doesn't matter from one service to the other.

[Gary RVRoamer]

In my opinion, brand is irrelevant when topping up.

[bob109]

Quote:

Originally Posted by SSteve Is it OK to "top-up" the oil level on our CAT C7 with a brand of oil other than what went in it at the last service? Its a given that the type (dino or syn) and viscosity will be the same. We full-time and it occurred to us that each future service could find us with a different brand of oil and will be left with the choice of either buying some of the "new" brand to top-up and discarding the old, or just use what's left of the old. Any advice? Thanks, Steve

Shell Rotella is a safe choice. It is available as 15W-40 in both dino and syn.

Here's the facts on Rotella

Shell Rotella T - Wikipedia, the free encyclopedia

[RustyJC]

I'm not ready to sign onto the "whatever you can get" ticket. I do agree that you could use any oil that meets API CI-4+ or CJ-4 (4 cycle diesel engine) specs and is of the same or similar viscosity, but I wouldn't throw anything I have in the garage in an expensive diesel engine due to possible additive compatibility issues, etc.

I've always run my diesels on Chevron Delo 400 15w-40, but Shell Rotella is an excellent oil as well, as is Mobil Delvac.

Rusty

[Stillwater]

I would not mix oils. I would only use Delo 400 or Rotella T 15w40 which are highly rated oils with a lot of faithful followers. I've seen good results in fleets of 150-200 engines with both brands. I use Rotella T because it's more widely available. Even Wal Mart sells it.

[swampdog]

the US Airforce buys oil from many different sources and stores it in thanks that can hold 1000's of gals. at a time, all mixed together , if they don't mind putting it in jet's I guess i don't mind mixing it in my cat to top it off.least if my motor stops running i'm not falling 50,000 ft.

[ImagineIF]

Use a brand name of the same API rating required by the engine manufacture and the viscosity that's currently in the engine. It really is as simple as that. I always carry a gallon of whatever I've used, as I believe you should use the same brand, when you can. The other thing to keep in mind is why use a oil that's not readily available at any trick stop.

[potsie]

Quote:

Originally Posted by swampdog the US Airforce buys oil from many different sources and stores it in thanks that can hold 1000's of gals. at a time, all mixed together , if they don't mind putting it in jet's I guess i don't mind mixing it in my cat to top it off.least if my motor stops running i'm not falling 50,000 ft.

I took an auto repair class in which the instructor told us that basically two refineries supply all U.S. oil, the difference between brands (labels) being the color of dye used in each oil. Therefore the only possible problem with mixing oils is possibly the incompatibility of the chemical molecules in the different molecules of color. FIY.