Synthetic oil change-over
My big question is when is a good time or mileage to switch over to synthetic? i have heard many different mileages/times. Any good thoughts? I currently have 13000 miles on my C-7 pulling a heavy ra...
Forum Discussion
Hank MI wrote:Jarlaxle wrote:
Oil is oil. If you like wasting money, go for synthetic. Otherwise...use whatever 15W-40 you can get the cheapest.
If that's what you believe then go with it. Personally I think you're wrong but that's okay. Syn doesn't start breaking down until higher temps than dino oil. Syn reduces friction more than dino oil does. Different oils have different additives that do make them different. I can provide you with a list of oils, wear tested by an engineer, that shows how many PSI all the leading brands will survive before 2 pieces of steel start to wear or scuff. There are huge differences but if you want the cheapest then by all means buy the cheapest.
15-40? Is that what your engine manufacturer recommends? That's pretty heavy oil.
Oil is oil. Synthetics are better, but it just doesn't matter, because regular oil is more than good enough. I watched an F-550 wind up 930,000+ miles on whatever oil the company got the cheapest!
Most diesels (including the C7 Cat) call for 15W-40 oil.
