I've used Royal Purple for a number of years. My long term experience has been in my pickup truck (280k miles) and the wife's Lumina van (140k miles) with no issues (barely broken in, by MB standards). I've put it in my 190E for the last 60k. I change the filter at 4k, oil at 8k.hempev said:I just visited Diesel Giant and his oil change page shows Amsoil. No-one using the Purple stuff? If you'd normally stick to 3K or even 5k mi. change schedule, seems you'd have to go waaay more to justify the added cost. Unless there's some proof one of the synth oils does something magic, I'll probably just go with the lowest priced 20W50 and regular changes.
My brother has a Chevy pickup with over 400k that he uses Mobil 1, oil and filter change at 10k.
I would endorse RP as good stuff, but you wouldn't hear me say it has an advantage over other synthetics.