So i upgraded my stock tires to Nitto Terra Grappler LT285/75/17, i think it was a 29' to a 33.8' so my speedometer is waaaay off, and i never know how fast im actually going, anyone know how or where to get this fixed?

Thanks a tun

 

You have three basic options:

1. Call the dealer and see if the Ford software will allow re-programming the truck to the new tire size. The IDS software is very limited as to what tire sizes it can put in the PCM
2. Get a tuner with custom (or canned - not recommended) tunes. Please read the stickies and the 1000000000s of posts in this forum if you have questions about tuners, tunes, benefits, how-to, where to buy, where not to buy, etc.
3. Spend about 60% of No.2 cost and get a HyperCrap speedometer calibrator. Pray that it works 'cause customer service is not HyperTech's strong suit.

http://www.hypertech.com/products-sp...alibrator.aspx

 

X2......

 

Here's a fourth solution: get a GPS that shows your speed. Then, ignore your dashboard reading.

- Jack

 

Jackandjanet, Iv done that already but i thougth if i could fix it for relatively cheap then id fix it, thanks for the help guys