howarmat

that is interesting. i have never seen anything like it.

by the way, going from 3.55->4.10 would mean that you actual speed is 86.5% of what the speedo shows, so if you are cruisin @ 80 the speedo would say you are going about 92

J to the C

some/my GPS has a speedomoter in it why not use it and not recalibrate the speedo? Use it once get use to the mph on the speedo vs the GPS use your memory speedo vs recorded -problem solved.

howarmat

he doesnt need to do that that because he will have a tune, he is asking is there a way when he sells the car so the other person will not have to deal with it. Also i think the odometer might not read correctly if you dont recalibrate it. Not sure though

d_ames117

Yes, if you don't switch the tune you will be putting phantom miles on your car. You'll be putting 13.5% more miles on your car than you actually travelled. Over 20,000 miles that's 2700 miles.

07torchredgt

Your right Howarmat, and yes the Odometer would be putting on too many miles... That speedocal Says its for 99-04.. Would it work on an 05+?

157dB

Being under the impression that the dealer is going to install these gears,
I would have the dealer change the settings in the stock tune parameters.
Then when you upload a new 91 tune, adjust the 91 tune for the 4.10s.
If and when sold, reload the 'stock, dealer modified for 4.10s' tune.
Could this work, Howarmat?
Make the dealer who installs the gears change the stock tune gear ratio?

howarmat

The dealers cannot modify the stock tune for the gears. There are a few reports they might be able to do 3.73 since itsa factory size in the shelby/bullitt but since no mustang hsa 4.10s from the factory its not an option. Not for sure on this but several people have reported simliar answers.

Bottom line is I know of no way to have a "stock" tune with the new gear settings and you always would have to run a aftermarket tune for the 4.10s