Wheels and tire ratio question

[Plymouth man]

I put 245 tires on my 68 fury and it has 3.23 rear ratio does anyone know how much that will change my ratio

 

[bronze turbine]

245 is the width of the tire. You would need to know the diameter vs. the diameter of the factory tire. Then, there's calculators on the internet.

 

[Plymouth man]

Well the old tire was 28 inches tall and the new one is 31 inches

 

[HOT FURY]

sounds like you have all the info you need to figure it out if you know the diameter difference

 

[Dads300]

What 245 are you running that is that tall??
Travis..

 

[MoPar~Man]

What is the exact size of your tire?

The tire size is usually visible on the side wall of the tire. In your case it will start with 245, then another number, then the letter R, then a number like 14 or 15 or 16 or maybe a little higher.

 

[CBODY67]

There are several different versions of the same calculator out there. The first one I found was on the Mazda Miata enthusiast website. Put in the size designation on the sidewall, with what the original tire size was and then what it was changed to. As in original size of P2125/75-14 and then for the new size P245/60R-15 . . . or whatever they might have been.

What will result is an overlay of the orig tire and the new tire, as to tallness and width. It will also spit out a correction factor for the odometer and speedometer with the current tire size.

OR, you can use a GPS app on your phone to read actual speed via satellite (in the sky).

Enjoy!
CBODY67

 

[66 Monaco 500 365]

your spedo will be 10% slower showing 50 when you are doing 55, as will your odometer, it will be only 0.9 miles per actual mile
If you do fuel economy calculation, it will 10% better than calculated.
If you have a 30 tooth speedometer gear put a 27 tooth in, that will put it back to normal
My $.02