What tire size is best for a accurate speedometer reading

lalojamesliz1

New member
When I first got my all-trac it had 205/40r16 tires. I put on 215/50r16 tires and noticed a big difference in acceleration and my speedometer reads lower but I dont remember how accurate it was with the 205/40 tires. This was back in 2011 or something.

I'm having a hard time finding good 215 width tires for my 16 wheels and thought of upgrading my wheels to 17x8 but funds are tight.
Is there a recommendation for the tire diameter ro have a accurate speedometer and not put excessive load on the engine? I cracked ringland #3 when I first got these tires (215/50r16) but it was a hot day and I was experimenting with a mspnp diy kit.
Would you guys say 205/40r16 tires are too small in diameter or just right?
 

FC Zach

Active member
When using a different size wheel and wanting to keep the same aspect ratio of the OE tire size, you'll need to use a calculator https://tiresize.com/calculator/

If you don't care about the keeping it the same and just want to run a readily available size for your wheel, you'll still need this for your spare.
 

underscore

Well-known member
Tires being slightly larger or smaller won't have a noticeable impact on the engine. 4x4 guys increase tire size by several inches without issues so the tiny differences in size you're talking about won't hurt anything.
 

Magroo

New member
I'm using 205/55/16 and its pretty close or so my speedo tells me. An added benefit is they are pretty cheap and easy to find.
 

Corey

Active member
Since moving up to 225/45/17 my speedo is bang on now. But the rolling diameter is noticeable larger, and results in a taller ride height.
 
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