A couple of weeks ago I made a post about Mobil1 and Schaffers.I still am very happy with Schaffers but man,I don't think the Mobil1 is working well in my 2 main rides(99 Corolla,02 Sienna). I have always used M1 inmy Corolla since new.I really didn't feel anything was wrong with it but started to experiment with other brands in my Corolla since joining the board. I tried Chevron 10W30,nice and quiet engine but man it felt sluggish.I tried Exxon Superflo 5W30,man the engine ran quietly and revved fantastically!Really came alive.Ran it for around 1500 miles then chickened out and went back to M1. The M1 5W30 feels just as sluggish as the Chevron 10W30 in my Corolla.I gotta mash the gas kinda hard to get above 3,500 RPMS to get goin everytime.This is an automatic trans BTW. Kept M1 in for around 700 miles then dumped for some Havoline 5W30.Another sluggish performance so to speak in my Corolla. I'm goin back to Exxon 5W30 as it makes this car that much more fun to drive. I use M1 5W30 in my 02 Sienna since new,changed every 5K with the first batch going in at 1,230 miles. Currently the van has 15,500 miles on it and it's due for an oil change.I was planning to buy a 5qt jug from Walmart but man this price jack to $22 tee'd me off. I think I'll use Superflo with a 3K interval this time.I'll let you guys know how the engine feels by a seat of the pants report after the change. I'm starting to really like this Superflo stuff. Price and performance wise. Next thing you know I'll be looking at Supertech!