Just wanted to say WOW! About a year ago I saw a slow reduction in the miles per gallon from 18.5 to 16.25 in and out of town. I've made regular oil changes and the engine has been well maintained since I purchased the truck new. Now I'm getting 17.75 to 18.25 again just by using a quart of stabilizer at oil change. PS the engine has 177,000.00 miles. Got to hand it you you guys, great product.