I happened to see a new Pete 379 with a X-15/10 speed at a truck stop. The proud new owner had the hood open and was spiffing it up. The one thing I did notice was there was a minimum of extra piping and equipment associated with the emission controls. Serviceability was much better than most previous emission engines.
80k miles between PMs? And I thought it was stupid going 50k between PM's. At an average speed of say 50 mph, that equates to a minimum of about 1000hrs. I've always done oil changes at 500 hours and I honestly wouldn't feel comfortable pushing beyond that. No wonder these new engines #### the bed so often. All that dirty, carboned up oil circulating through there.
I've done some research on this subject. I used to do my D13 @ 25K, It used about a quart in that time. ANYWAY-
It seems one of the disclaimers in these marathon oil change intervals is the usage, and they factor the usage by MPG. Like if you get 6.5 or greater, you can push to 50K with synthetic, still haven't found the 80K nomenclature. I think most people will still be at the 30K mark in the real world.
Just because a book says something doesn't mean common sense and savvy should be thrown to the wind.
EXAMPLE: My new Camaro is supposed to go 7500 between oil changes using a full synthetic 5W-30. However talking to the service manager at Chevy, he said do to our extreme environment in the desert, heat & especially dust, to do it @ 5000, and I will never have a problem.
Now I could take the " New Prime Inc. " stance I suppose, and go by the book says, and the engine is warrantied for 5 years 50K so what difference does it make anyway.
I guess it doesn't if you want a new engine at 50,005 miles.