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37z and speedometer
Posted: Tue Aug 11, 2020 8:46 pm
by beachbunny1959
how far off is the speedo wearing 37z?
tia
Re: 37z and speedometer
Posted: Wed Aug 12, 2020 9:51 am
by ScubaSteve
I don't remember exactly, but its enough that its worth having it recalibrated. Not difficult at all if you get an OBDlink and AlfaOBD. No idea what the dealership would charge.
Re: 37z and speedometer
Posted: Mon Aug 17, 2020 11:30 am
by Bill2014
Tire circumference is Pi times diameter.
Stock tires are approximately 33" in diameter and you are running 37's
So your actual speed will be 37/33 what is reading on the speedometer.
If you don't make a correction, when your speedometer reads 60mph you will actually be going 60x37/33 = 67.3mph
But you need to get your computer set for 37" tires to correct your shifting points...
Re: 37z and speedometer
Posted: Thu Dec 31, 2020 8:24 am
by TroyH
Mine is about 7 MPH off, you really notice it on the down shift, or the 2 to 3 shift under minimal load. I will be getting a programmer soon. Just have not decided which one.
Re: 37z and speedometer
Posted: Thu Jan 21, 2021 3:00 pm
by iowa
I just got the new and improved AEV Procal Snap. So far it’s working great.