Like others, I’ve been using various oil additives for years. I’ll try anything once. I have two cars. 1998 Avalon V6 for summer and 2001 Buick 3.1 V6 for winter. Recently tried this stuff on the Avalon with 188,000 miles. I could be imagining this but it seems to run peppier! Time will tell for gas mileage. I’ll use this product next fall on my Buick. Cold start-ups should be better.