winter engine oil? sticker on visor 10w30

[Corpse]

i was at my local parts store asking for a diesel specific 10w30 engine oil but they said they didn't carry any and that the local tdi vw guys just run full synthetic 10w30...
what are you guys running in the winter?
during the summer i ran 15w40 rotella t

thanks

[twaddle]

I usually run all year on 0W-40 and have done for years. Occasionally if I wanted to safe some money I would use 15W-40 in the summer and go back onto 0W-40 for the winter (Did that this year). My 96 K1500 is now up at over 281000 miles.

Merry Christmas and a Happy New Year

Jim

[DennisG01]

I used to run 15-40 in the summer and 10-30 (both dino oil) in the winter. For a few years now, I've just been running Rotella T6 synthetic year round - it's 5-40.

[Corpse]

so a regular 10w30 motor oil is ok to run in the diesel? it doesn't require something specific to diesel engines?

[DmaxMaverick]

so a regular 10w30 motor oil is ok to run in the diesel? it doesn't require something specific to diesel engines?

No. The oil must be "C" rated, preferably "CG" or later (the second letter increments with updated formulation). "CF" rated oil is 1980-ish. Most common 10w-30 oils (primarily "S" rated, late design for gasser cars) are CD to CF at best. I've not heard of any manufacturer recommending "non Diesel" engine oil for their Diesels, but if they did, it would certainly apply to the latest models, and only import cars. All US brands still recommend the latest "Diesel" rated engine oil, which is about the CI/J-4 rating. I haven't looked into it in a while, but the later formulations have changed more frequently, presumably to accommodate recent Diesel fuel requirements.

[DennisG01]

so a regular 10w30 motor oil is ok to run in the diesel? it doesn't require something specific to diesel engines?

No, like Dmax said it must be diesel rated. For what it's worth, the T6 has a CJ-4 rating.

[mrwilecoyote]

I have heard stories in really cold climates of the oil pump shaft breaking with 15w40 on startup. KNock on wood has never happended to me but I primed one in 40 deg weather with a speed wrench and there was a decent amount of resistance. I am been contemplating running lighter oil myself. It was cold the other morning. It was on my mind. But then I worry about running thinner oil with the rpms I run.