I'm sure this has been beaten time n time again but I have yet to read anything about it that I can figure out. How do I fix my odometer and speedo since I put 34's on my truck?? What numbers do I need to put were??? I havnt checked to see how much the odometer is off but I did check my speed with the gps and it seems to be dead on were before with stock tires my speedo read a little faster than I was goin by the gps. So someone plz help?? I'm stupid when it comes to math and numbers.

 

just get a sharpie and just add 5mph to everything. wright it directly over the stock numbers.















and if you go and do that, it will be my laugh of the day (maybe week). you need a programmer to reset your computer to adjust for the tire size.

 

Most good programmers have an option to adjust the speedo speed for tire size increase. Google any programmers site before you buy to verify they have this option. It's as easy as entering yoiur tire size into the programmers option menu for this feature.

And yes, it has been talked about many times before. The search will show this.

 

I have a gryphon. And I did search but none of them explained it for me to understand it. Like I said I'm not good with numbers and math

 

Doing a search for the conversion size is so simple. Thanks!
Contact the tuner.

Edit: Either a sense of humor or take things with a grain of salt.

 

Ha you got that from me. Anyways OP rednek is just playing giving you a little bit of what many people like to call sarcasm (lots of that on the forum). The equation I use to calculate MM to inches is simple to use.

2(SAR(TW/25.4))+RD = TS

SAR= Sidewall Aspect Ratio (marked by / after width then corresponds with a number such as 60,65,70)
TW= Tire Width (the number that is 255,265,275, etc.)
RD= Rim Diameter
TS= Tire Size

Don't forget order of operations from High School

PEMDAS:
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Also keep in mind what many people like to call the squish theory which basically states that the vehicle's weight sits on rubber which is not very resistive to "squish." A 33" tire may come out to be a 32.1-32.5 tire depending on tire pressure and weight of the vehicle. You can also somewhat confirm your answer above by taking a tape measure and measuring the diameter of the tire while it is on the ground. That's about all you need to know, but next time please use the search function! Also I see you're new so I will cut you some slack this time.

P.S. The order of operations thing isn't to make you feel ignorant or dumb just reminding you of silly high school stuff.

 

Ya still lost me! Told u I'm not a math wiz I HATED math!!! Anyways someone on PHP forum helped me and done it for me but thanks for YOUR help. I did use the search, again I'm not that stupid or new to forums just none of them answered it for me. As for the sarcasm I can take jokes and all that but the way it was put was insulting. But that's cool, whatever, if that's what makes him feel big and good about himself it ain't bothering me, I still sleep at night!! ? Thanks anyways!

 

Using the search works sometimes, but may not always yield what you are looking for. I do understand that. Glad you were able to find your answer.
Maybe someone will search and find this thread or you will be able to help them.
Some posters are on the forum because they have nothing else to do (I seem to remember that comment). Have a good day!

 

you got 3 options

1. buy yourself a programmer to reflash your computer. There are instructions on the programmer to tell you how to calculate the new tire size.

2. Take it to the dealer and have it reflashed.

3. Just deal with it being off

oh and forgot one go off the mph of the gps

 

Thanks but I figured the numbers I needed to put in my gryphon!