I get 20 plus mpg compared to an average of 17.6 mpg in my 2001 Dodge Ram 4x4 Diesel. I've noticed on a steep climb where in the past the automatic came out of OD about halfway up the hill, now it just keeps blowing into OD. There is some concern hauling a heavy (13,500lb) trailer up a hill without a 10,000cfm clutch fan, I had to climb vines three times to cool off. I'm planning to separate the transmission cooling with an external cooler and see what that does for me. So far I am very happy with the Flex-a-lite 262.