It works very well for the guy that wants good towing power, without having to babysit his exhaust guage. Mileage/power will go up, exhaust temps go down, and a smile will go on your face.:;
I have two friends running the Smarty Jr on auto trucks. The truck with gauges noticed cooler EGT's when towing by 100deg or so. The gauged truck also had a fuel mileage increase of 1-2mpg. The second truck has no gauges. Second truck noticed a .5mpg increase. Both trucks are running slightly oversize Toyo MT tires. Both truck owners are very happy with the Smarty Jr. Different friend and I are running the Full Smarty. We're also very happy.