tire size

[hot rod]

i have 18x8.50-8 tires on my cart. plan to put 19x7-8 directional tires on the back. will this effect my speed and torque? and if so how?

[MuckSavage]

It'll drop your torque a bit, raise your speed a bit. Search around the forums. There's countless threads on Tire size affecting speed & torque

[JohnnieB]

Originally Posted by hot rod

i have 18x8.50-8 tires on my cart. plan to put 19x7-8 directional tires on the back. will this effect my speed and torque? and if so how?

The taller the tire the fast the top speed and the lesser amount of force applied were rubber meets road.

Going from 18" to 19" is a 6% increase in speed and a 5% reduction in torque.

However, the sizes stamped on the sidewalls of tires is a group size rather than actual size, so the true height may be more than a inch off in either direction, which means the height difference between an 18" and a 19" tire could be none at all or two inches or more.

You will have to physically measure the mounted height of both to find out what the change will be.

Also, if the tires with the directional tread are low pressure types (max inflation pressure 10PSI or less) they may reduce the top speed even if they are taller, and dig deeper into the available torque.