For specs, just log onto both companies' web sites and open the respective product data sheets. I've used Mobil Drive Clean in my wife's '00 Cavalier and had no problems with oil consumption, weird noises at startup, or fuel mileage. I bought a crapload of Chevron Supreme 10W-30 while it was on closeout at Target and will be using it in a Hyundai Sonata V6 (currently 4,800 miles on the clock) purchased last December as soon as I use up my remaining stock of WallyWorld SuperTech 10W-30. Both Exxon/Mobil and ChevronTexaco have been and are at the forefront of hydroprocessing technology in base stock refining. (Both Mobil Drive Clean and Chevron Supreme use Group-II base stocks I believe.) If you'll be doing 3,000 mile oil changes like me, I don't think you'll be putting your motor at risk with either. The last I read on the subject, it appears that Chevron is now adding molybdenum to Chevron Supreme, though the previous formulation showed good wear numbers even without it. Dunno offhand about Mobil Drive Clean. Is either really superior to the other? No idea. Would I pay the extra 13 cents a quart for Mobil even if it was superior? No.
[ April 27, 2003, 12:50 AM: Message edited by: Ray H ]