i know u can tune the vehicles computer with a labtop.my truck is a 98 with a 4l60e...but can u get a program to correct the speedometer? i like the hypertech max energy programmer.but its expensive.its got a good power gain but thats running 93 octane.thats not a option for me.it can do all kinds of other stuff.but it says on the site it only goes up to a 34 inch tire size.i would rather learn how to tune the air fuel ratio and so forth my self just wondering about correcting the speedometer