PP1 convert what tires keep the speedo accurate?

[Mustanggtvert32907]

Hey guys I’m looking at getting some wider tires for rear I have the PP1 wheels now I want to run either a 305 or 325 to handle a supercharger. What front and rear setup would not mess with the speedo? Any help would be awesome. Thanks guys

Sponsored

 

[MidwayJ]

Hey guys I’m looking at getting some wider tires for rear I have the PP1 wheels now I want to run either a 305 or 325 to handle a supercharger. What front and rear setup would not mess with the speedo? Any help would be awesome. Thanks guys

For the least impact to the speedometer, you want the diameter of the new tires to be as close as possible to the tires that came with the car. I believe it's the rear tires that the speedometer is tied to. So for example, if the original rear tire is 275/40r19, Google the diameter. Then Google the diameter of the sizes you are considering for the rear. Whatever comes closest will change the speedometer least.

 

[2017GBGTPP]

I use this site:

https://tiresize.com/calculator/

It will tell you the difference in speed based on the tire size, just play around with the dimensions until you get something to your liking.

 

[toplesstripcruiser]

And if I had to choose, I’d get one that’s a little larger in diameter for a few advantages:
1. The speedo will read a little lower compared to how fast you’re really going. I wouldn’t want to think I hit 60 when I was only going 57.
2. Better fuel mileage. Wheels won’t be spinning as much per mile, less fuel used.
3. Getting a taller tire would be like getting a taller gear. This will help in your supercharged applications. Less likely to lose traction.
4. Rear maybe raised a little higher.
5. It will fill a little of the wheel gap.

I also thought it might throw off your fuel mileage computer. Since the wheel won’t be turning as much per mile, it would think it’s not going as far. But then again you won’t be using as much fuel either, so they cancel each other out. (I hope that makes sense)

Sponsored