dln11

Just picked up my Ecoboost yesterday afternoon. I installed a 2"AS Leveling Kit, 3" Rear Block, and mounted 285/65/20 BFG ATs. Everything went smooth until I asked the dealer to program the tire size in the PCM.

The dealer has informed me that the stock size was the largest that they could program. I've been searching through many of the forums, and yes, I realize that a person can purchase a Hypertech Tire Size Calibration Tool. However, the tool is not available for the Ecoboost.

I've also read that the dealer may not know the right way to do this. I know my dealer well, and I'm sure they would be willing to try any of your knowledge that I could pass along. If you know how to do this at the dealer level, please give me some detail. Or if you know of an cheap way of programming the Ecoboost, I'd like to know about it.

I'd appreciate any help you can give me. I know I can run with it the way it is, but I'm kind of a picky person and just want it right for milage, mpg, and speed! Thanks in advance.

By the way, here is a pic of the new ride.

hijinx

Looks great, It would be nice when someone comes out with a programmer for our trucks.

Ok, start with the you,ll screw up your warranty kid, posts

pfbz

Looks great! (but tint the front windows! )

Curious about the tire programming as well. I thought there was another thread with some info on this... maybe with traction control in the titile?

sk8inrj1

Is it possible to have the dealer change the gear ratio (in the programming) from say 3.73 to 3.55 to compensate for the larger tires?

NASSTY

If they can change the ratio to compensate for larger tires.It would need to go the other way 3.73 to 4.10

shortride

iTrader: (1)

I've attempted to advise others that Ford only has in there computer the factory recommended tires that can be reprogrammed to make the speedometer and odometer accurate. It appears that you did what a lot of other have done. I always ask the dealer what those sizes are before I purchase the tires.

It's fairly simple to look up the specification and see what tires sizes are offered on the late model F150's.

17" steel wheels, P235/70R17 (4x2) and P235/75R17 (4x4)
20" aluminum wheels, P275/55R20 (4x2) and P275/55R20 (4x4)
22" aluminum wheels, P275/45R22 All Season BSW "V" rated

Yippie21

dln11,.... your truck looks GREAT. Good luck with your quest. I'm sure in time someone will come out with a programmer. Your mpgs are going in the toilet anyway, so I can't imagine that will matter much. What gear ratio did you get, 3.55 or 3.73?.. or higher? And with those tires, you are so close to stock, your speedo is only going to be off a tad...

11screw50

nope. if you were actually replacing the gears, you would need to go 4.10's to get back to where the 3.73's are now but the bigger tires make it act like the gearing is higher (lower numerically), not lower (ie, at the same speed, you are now turning fewer rpm with the same gears and bigger tires, same effect as higher gears, same size tires).

NASSTY

I thought that's what I said.I corrected the guy that said to go from 3.73 to 3.55 and I said to go from 3.73 to 4.10 for larger tires.

11screw50

if you change it in the computer, you would need to change it to 3.55's so that it accounts for the fact that your larger tires will cover more ground than stock at the same (engine) rpm.

if you change the actual gears, you would need to go to 4.10's so that the larger tires actually cover the same amount of ground as stock at the same (engine) rpm (because the computer still thinks you have 3.73's).