So I have a new 2014 fx4 5.0 and I'm looking at keeping the stock 20's on it and getting a two inch leveling kit with 295 55r 20 nitto trail grapplers. My main question is, once I get my new tires and leveling kit how can I get my speedometer calibrated back to normal without using a programmer? I am new to the forum so don't spat me if this question has been asked before, I just couldn't already find a forum on it. I have heard that if you run programmers to recalibrate for this, it will void a warranty? I for sure don't want to go that route if that's the case but I have been told from a buddy that if you take it to the ford dealer they can recalibrate it to the size of the tire that I will be adding to it. Can somebody who knows more about this please help me out? I plan on getting a programmer later on once my warranty will be up but for now I wanted to see what my options are without it. I'm just sure going from a 275 55r 20 to a 295 55r 20 my shift points aren't going to be spot on with a bigger tire. Let me know what yall think I'm all ears and I apprecaite any information.

 

I ran 285/55R20s without much impact on my shift points, the 295s will have a bit more. Ask your dealer if flashing for a different gear ratio might get close. Outside of that, you're talking Tuner. Good luck.

 

This years best useless reply ^.

I once had a teacher that had a plaque over the door to the room that had a saying that really made sense.

[Put your brain into gear before you put your mouth into motion]

 

OP you may be able to have your local dealer reprogram the system to match your selection be it over sized tires, gear changes etc....

Your best bet and does not involve the dealer is to get a tuner, you can change everything related using it.

I also suggest you google search "Magnuson–Moss Warranty Act" < ammo.

 

You already messed with your warranty... the level kit and bigger tires could void your warranty.. why worry about a tuner now..

 

The new tire circumference is the same. 295's are just wider than 275's, so no conversion is necessary
295 width 275 width
55R side wall depth vs. 55R side wall depth
20 rim diameter 20 rim diameter

both are 55R 20's you will have more rubber on the road with the 295's so you may experience a decrease in fuel economy.

 

The '55' is a ratio, not a fixed number.

The 295 is a nominal 32.8" tall tire

The 275 is a nominal 31.9" tall tire.

Fire up ye tire calculator of choice to confirm fer yeseff.

To the OP: I concur wif the others, just go buy a good programmer (recommend SCT X4 with custom tunes). It'll help with the marginal power loss and recalibration concerns. Well worth it fer the shift strategy improvements alone.

MGD

 

Fuzzy Math...