firstang001

Hi Guys, I recently bought a 2013 Mustang V6. These came with 17inch wheels stock. I hated them. I immediately found a local deal who was selling the 2014 Ford GT Track pack 19inch wheels. I always wanted to go that route and grabbed them instantly. Got them installed and they look amazing. But I wanted to know if I should be getting my odometer re calibrated? Can I test my speedo/Odo test in anyway?
Thanks......

Ltngdrvr

Those new tires are shorter than the stockers so the speedo will read high now.

Unfortunately, there is no recalibration available short of a pcm tune.

Now, if you want a factory tune that will match the tire size for the V6, the Performance Package cars came with the same tires. So, you can get a dealer to reflash the pcm with the Perf Pack tune to correct the speedo.

Only other option is an aftermarket tune, but then you have warranty issues possible.

firstang001

I thought that the shorter tire size is compensated by the bigger rim(17 inch -->19inch) ? I know it looks stupid but I did a side by side size comparison while shop was installing them they look identical to the naked eye. Do you have an idea how much the dealer will charge to do the reflash?
Aftermarket tune..Hmmmm, This is only for the PCM right?
I am sorry if I have too many dumb questions...very naive at this

Ltngdrvr

Speedo calibration is within the tune.

If your V6 is a manual, tires are 27.7" tall, the track pack tires are 27" tall.

Wheel size has basically nothing to do with tire outer diameters, except that the outer diameter is bigger than the inner diameter(captain obvious ), they come in lots of different sizes.

How much the dealer charges for the reflash depends on the dealer, probably will charge you an hour for a twenty minute job, so $90 to $110 probably.

firstang001

Can I contact AM with the upgrade and will they be able to help me out with the tune?

i found a nice website that can compare tire sizes and speed difference....

http://tire-size-conversion.com/tire-size-comparison/

Ltngdrvr

Yeah, sure, if a aftermarket tune is how you want to handle it.

Their cheapest tuner runs about $380 before the forum discount.

And as I stated above, you then face the possibility of warranty issues.

firstang001

Thank you for the input my friend! I will need to think about what I should do with it.

Joeywhat

The speedo should only be off by 2-3 mph at 70mph, so it's not going to be a huge difference.

laserred38

OP, you could also step the tires up to 275/40/19. This is a very common and popular size that people with those wheels are running - overall diameter on the 275/40s is exactly 27.7 give it take a tenth depending on different tires. You could see the Pirellis to offset the cost too...just food for thought.

pressman43

I always use my Garmin GPS when I want to confirm speedometer accuracy. It seems to work pretty good and you'll know how much it's off.

firstang001

From what i konw... its 2.2% increase.. so for every 100 actual miles traveled odo will be off by 2.2miles..

firstang001

This will be an better fix i think.. I will just wait until the tires wear off and buy tires with this size. Thanks you!!

firstang001

I do not have a GPS as I use my phone for navigation. I think I can install an app on my phone which shows the speed. And then do the comparison.

laserred38

I believe the Waze app does this, but you have to have it open. But yeah, I'd do some 275/40s when the stock ones are shot

firstang001

i installed DigiHUD app.. pretty slick..

firstang001

You all should try DigiHUD app.. I had it installed on my phone and used it its pretty coool. You can even use this as a HUD app. Turn it on in HUD mode let the phone sit on the dash and you can see the speed on the windshield. pretty cool...

laserred38

Nice, it must invert the text so it shows up correctly on the reflection?

firstang001

Yes it is... if you are wearing polarized glass loose it....

Jazzman442

As part of the installation package the dealer should of told you and did the Change in the PCM. I did the same thing on my Suburban and the Dealer while installing the new tires and rims did the PCM change.

It doe snot take long. It takes longer to get the computer out and connected than it does to update the PCM?

Ltngdrvr

Don't think the OP had the dealer doing anything on his car.

And they don't remove the pcm to do anything to it, they only have to hook up to the OBDII port.