ive ran both...before the supercharger i was running the sl version of the chevron and going 5,000 miles with great reports...i change all my vehicles at 5,000 miles. at 1.25 quart the chevron was doing excellent in all my cars so i thought why should i spend 5 per quart when i can get the same results for 1.25 per quart?? but after seeing this anaylisis for 3,000 i was kinda surprised at the tbn and vis....i really thought 5,000 mile intervals would be no problem...i guess all the city driving coupled with supercharger running a little rich its chewing the oil up good....i posted this to see get opinions and i may go back to syn IF I MUST...keep em coming guys....thanks, john