Trucks that get up to 50 Miles Per Gallon In his book, Shade Tree Conversions, Gary C. Brown, a small businessman in the Middle Georgia area, describes how average Americans can convert gas-guzzling vehicles into fuel efficient diesel vehicles that get up to 2-3 times more miles per gallon by installing diesel tractor engines into these vehicles. www.shadetreeconversions.com 1-478-956-3169