Mr. FH had one in his 2002 Dodge Dually and he intends to get one for the new pickup. There are various ones available, some are better than others. They will void your warranty, so you need to find one that is easy
to take off and put back on.
Lots of people here have them. Probably more do, than don't.
His was a PowerMax made by someone that worked for Cummins.
He never had any trouble with it. The one he is going to get this
time helps with fuel mileage too. Anyway, someone who has one
swears that it will help. Who knows? :wink: