I have a 2000 Ford F-250 4x4 powerstroke 7.3 diesel and I get 16-17 around town and 20 on the highway I've gotten as high as 22 Can't complain and it'll pull whatever you wanna hook to it...definately the way to go...A buddy of mine once told me this and I didn't believe him but after owning a diesel I do..he told me.."Real trucks don't have spark plugs" lol!