I was looking for articles but couldn't find anything, still learning to use the search function so it's probably just me.

Anyway in my constant thinking I've started pondering what kind of oil to use.

I have at my disposal a lot of BMW 5w30 full synthetic oil. Its pricey but I know a guy I've used it in my other vehicles and have had no issues. The API rating is SL/CF which means that it means the standards for a diesel of my model year (1990).

Is 5w30 ok to run year round in our trucks? It gets cold in the winter (below freezing) and hot in the summer (couple days at 100 deg last year). Just want to make sure before I do something dumb

 

IMO, winter yes, summer no.

 

if you're gonna be playing with oil that thin, it would be wise to have a real oil pressure gage so you can keep a close eye on it in different weather conditions. i wouldn't try it when its hot outside

 

Would 15w40 be ok for summer and winter duty? What do you guys recommend?

 

15w40 is what most of us run all year round. in extremely hot areas, 20w50 may be better, but 15w40 is just fine all year.

 

From -10 to 100+ i run 15-40, when its that cold its a little on the thick side and i think Ford actually recommends 10wt-30 or SAE 30wt. But just like any good gal you cant let em get too picky lol

 

I am using SAE30/10W30 synthetic year round, will be taking used oil analysis and no plans to ever change the oil, Only topping off and changing filters as I drive my truck.
Engine is new with about 5500 miles so far.
I am doing it not theorizing about it.


Javier

 

im going to 5w 30 synthetic (almost) year round as well due to these fuel prices.been running 5w 40.-July & Aug she'll get 40w still though.

 

Its my understanding that moble1 full syn 0-40 is a thick oil that mecedes use's in all it,s new cars...it has a mecedes part # on the lable, I may try it after I install real pressure gauge, to monitor things,

 

I ended up running Castrol 15w40 and a PSD filter. I am still curious about running 5w30 but not until I have some good gauges and all the other bugs are worked out.

BMW diesel oil is Castrol 5w30 full synthetic. The oil I used is for vehicles that do not require synthetic (think old lol) and has the same API rating of SM/CF