I ran two oil changes , total of 6000 mi, of the Exxon 10/30 in my son's POS Buick beater with the 3.8 v6. The oil use doubled, compared to the Chevron/Havoline that was used before and after the Exxon. Since I keep all the records for the car, the Exxon was used during the same time of year and conditions as the Havoline, summer use was not the problem. I still have two quarts left of the Exxon, and it will be saved for the old push mower.