Speedo gear question

[guidoverduci]

Currently have 18 tooth and I'm reading 55mph with 65mph on the gps. That's with 3.50s. I'm putting 4.11s in and wondering what effect that will have. I'll probably just order both 17 & 16 to be safe. Do they come lower?

 

[Viperwolf1]

Right now your speedo is 18% slow. After the change to 4.11 (17% rpm increase) it will be very close with your 18 tooth gear.

 

[Broncobowsher]

They only come as low as 16 tooth.
That 18 should be as good as you can get once you get the 4.10's in. Lower gears will make the speedometer read faster, so the 4.10s should fix everything for you. If you go to a taller tire then you will need to look at a 17 tooth gear.

 

[dredgenot]

I have 4.11's with 33" tires and I'm running a 19 tooth gear. The only calibration I have done is pacing a prius with a digital dash, but the speedo is right on now. I did have and 18 tooth, but it always read slow.

 

[guidoverduci]

Thanks everyone! I have 35s so hopefully just the gear change will put it pretty close.