0W30 SJ or Heavy Duty API Cx?

[sub_zero]

The time is close for a change and I will be moving to 0W30, I drive short distances, mainly and in the winter even with 5W30 I get terrible milage.

It may make no difference at all but I'm a littl nutty I guess -

This is in a P/U with GM's 5.3L

Should I use a 0W30 rated for gasoline engines SJ, often referred to as passenger car oil. (PC Arctic 0W30)

Or

A Heavy Duty Motor Oil designed for Diesel and 'some' gasoline engines? (PC Duron XL 0W30)

BTW what is it that makes the difference between an API S and API C oil? Is it just better detergency and dispertion or is there a wear related component also?

 

[Howard]

I use the PC Duron XL 0W-30 in both my VW diesel and my F150. The F150 has a 4.9L inline six and gets the crap driven out of it. It spends a lot of time in front of a horse trailer. I change oil at 10km interval in the truck and 15km in the VW. Oil Analysis has let me know that this is still well within the capabilities of this oil. I have considered lengthening the interval to 15 or 20k but haven't yet.

Another thought that I have had recently is the Motorcraft 5W-20 oil. This is good oil for a gasser and should give good mileage results due to the 20 weight.