Anyone switch form 15w40 to 10w30 in 12.7 Detroit’s?

At 50k oil changed the main bearings are toast at 500,000 miles on any engine. It's just a fact.

 

Nope, tolerances are that tight and oil is that good. Sorry.

 

I agree my last Detroit got and overhaul due to dropped liner. At 825k oil changes at 15k bearings looked new. Since went to 20 k with no problem.

 

The oil is not good for 50k. Plain and simple unless it's synthetic. And tolerances being that tight wear the same as any tolerance.

 

15k and 20k oil change is still a far cry from 50k mile oil change.

 

@Cowpie1

 

Any time you change oil, you are removing wastes. THAT is good for any engine.

Otherwise it will suffer a form of plague. Clog it right up over time. We usually change the oil on our cars at 3000 miles right when that black comes halfway up to consume the gold.

 

If you have at least two good filters to filter out the crap and you change them at least twice somewhere in there, you could get by with it. I wouldn't think of running that long on an oil change with my truck, even changing filter every 10.

 

Auto Manufacturers have increased recommended oil changes to 7000 - 10000k . Between unleaded gas and improved detergents 3000 is really overkill. Spark plugs used to be good for 10k. I just changed a set first time on a 4 cyl 09 Pontiac at 120 k same reason unleaded gas electronic cleaner burn. Same car gets oil changed at 10 k Mobil 1. I admit I was a bit Leary at first but so far so good.

 

I used to change points at 6K, plugs at 10 as you say (Now they arre running about 60 to 80000 before I change. The factory plugs were changed at 80000 and they were doing pretty good. Two were burned.) and god knows what else.

I rage at the machine because you cannot do anything without a blessed computer in today's cars. I miss dearly with tears the old time 70's 351 holley engine or the chevy 305 with the carter carb etc. Those were the days. Easy peasy.