Sorry if this is a newbie question--I just got a lift and put 275/65/20 tires on my F150. Now my speedometer appears to be about 4mph off. Is this normal? Is there some type of recalibration I am supped to do?

 

Yes, it is normal. Your new tires have a larger OD than the stock ones.
You can make the adjustments using a tuner or Forscan.
Your choice of which one.

 

Forscan is the cheapest way. Or go back to the shop and ask them to do it.
Ford removed the ability from the dealer to do it for you. I found out when I took my truck in after changing rims and tires. They said the program they have no longer lets them change anything unless it is an option they could had been order from the factory.

if you have the EcoBoost then get a tuner from 5star and add a few HP and adjust for tires if you can afford it.

 

Yes I have the 3.5 EB. I’ve seen a lot of threads about Forscan but haven’t done any research on it and don’t know what it is frankly. I’ll look into it.

 

I upsized my tires as well. After doing it, I started looking at tuners to correct the speedometer....the cheapest I found was around $400.
You can get a $30 bluetooth dongle for a computer to do Forscan. Or, if you need a laptop, you can get one that runs on Windows for $150-200.

The advantage of using a tuner is that you can add HP/TQ and change the speedometer.
The advantage of using Forscan is that you can change a bunch of other settings to your truck.
OP, read the Forscan sticky and click the link in the first post to see if there are any other settings you might want to change...that should make the decision easier for you.

 

There's also the Hypertech calibrator. Probably the easiest.

 

This is what I used when I went to 35's. My laptop is a chromebook so I don't think I can use forscan with that. My only "issue" was the tire size I had to input on the programmer to make my speedo correct. I think I ended up with 33.25" to make my speedo match GPS.

 

Anyone in the Houston area with a Hypertech calibrator?

 

You'll find a lot more people with Forscan and a good OBD dongle...

 

The Hypertech will only work on one vehicle at a time.