[Thumper333]

Originally Posted by 328_Diesel

Why is it that over the road truckers can drive so many miles on a single oil change, but a car engine cannot?

Apples and oranges.

It MIGHT be they can go longer for a couple of reasons.

First, they have oil pans that hold about 8-12 GALLONS of oil. Yes GALLONS, not quarts. Even if you want to argue engine size the bare fact is those rigs have oil capacities around triple of a passenger car once displacement is factored. Then there is the fact that their filters are the size of country hams allowing for more dirt to be collected before becoming full. Finally, there is the fact that those engines get ripped apart and rebuilt regularly.

They run longer oil changes because of vastly different designs and because time is money to an OTR trucker, so pushing oil changes longer and staying on the road making money makes more sense to them since they will do a total rebuild before any oil longevity issues arise.

I agree that oil analysis is the best way to judge the state of your specific engine and conditions. There are many variables that affect oil change intervals and one set number of miles for everyone is foolish. However, I would perform the analysis and then reach a conclusion based on that, not decide on a conclusion and then plan to have the analysis prove it. but then I was raised on the scientific method.

[F32Fleet]

Originally Posted by 328_Diesel

Why is it that over the road truckers can drive so many miles on a single oil change, but a car engine cannot?.

Huge sumps, larger tolerances, and they run on hwy at full power most of the time.