I have a 2002 Ford F650 SuperCrewzer with the Cat 3126B and 6 speed auto, at 1800 RPM it travels at 60 MPH. I think these engines should not be run over 1800 RPM and when I do the MPG goes down. I would like to get more SPEED (don't we all) with out loosing MPG, would it be wise to change the rearend gears? or does someone know what would be a good solution.

Thanks

 

Larger diameter rear tires will give you more speed without more RPM, but your speedo will be off. A GPS can show you the exact speed your traveling, and you can make a cheat-sheet and tape it to the dash

Other than that, rear gears are the only other thing that will bring up your speed. Or an overdrive unit.

 

I don't think I like the cheat-sheet idea ...... I'll go with the gear change I think.



Thanks for the input

 

[quote=Tundra Pony;8930123]I don't think I like the cheat-sheet idea ...... I'll go with the gear change I think.

You do realize the gear change will throw the speedo off too?
Don't sweat the cheat sheet, not likely to get speeding tivkets in it.

 

yes I have thought about that and I do have a GPS that I use also. I am looking into what it takes to recalibrate the speedo

 

I used to have a '98 Ranger that came with 225/75R14 tires and I switched to 235/75R15 tires. I found out that the speedometer was actually "driven" by the computer so I took it to the Ford dealer and he reprogrammed the computer for the larger tires. Easy enough.

 

ok Thanks I will look into that, I am also looking at getting a programmer and I think that some of them will do this as well.