No issues- last vehicles had 202K (Cherokee 4.0) and 203K (Grand Cherokee 5.2) miles when I sold them and neither was burning oil.
Can't tell what difference it makes far-far past 200K because I don't intend on ever keeping them that long. Bottom line- Even if there is some marginal benefit over a longer life of a motor, for most people it will make no damn difference because you will never keep the vehicle that long. At 200K I imagine I'm statistically probably already an oddity!
I’ve been doing 25,000 mile oil changes since 1972. 12,500 mile filter changes until a couple of years ago, now 25,000 mile filter changes too.
I’ve driven over 2 million miles using this proven techology.
The most miles on a vehicle was a 1997 Saturn SL1. I put 479,000 miles on it with 35,000 mile oil changes. (Amsoil 0W-30 and Amsoil filters.)
Most of my vehicles have gotten better MPG than with petroleum oil.
Presently I have an ‘08 Grand Cherokee, ‘06 Ford Focus, ‘05 Rokon Trailbreaker, ‘97 Discovery, ‘83 Mercedes 300D, ‘73 Land Rover Lightweight, ‘66 Mercedes Benz Unimog and a ‘73 Grumman motorhome.
All have Amsoil throughout with oil changed at 25,000 miles or once per year.
This 100% synthetic oil is made in America, and has been PROVEN since 1972.