I recently lifted my 08 ram 6 inches and threw on 18 in rockstars and 35 nitto mud grapplers. Does anyone have any idea how much my speedo will be off from stock 20's? Any help is greatly appreciated.

 

enough to make a difference.

 

Well from one airman to another could i get some info that helps?

 

Lets see if a old sailor can give you a little schooling....
Stock wheel on 20" is 33". You now have 35's so that would be 33/35=.943 so subtract .943 from 1 = .057 so I would guess close to 6% error. good luck ....

 

not enough to get a ticket

 

aight sweet guys thanks for the info

 

i have 35s on mine and it depends but i am about 5mph off on my speedo. rim size dont really matter. its tire size. but its prolly around 3-5mph. get a buddy with a stock truck to drive next to you on the hwy and when you get to a constant speed have him check his speedo and tell you and compare it to your speedo. i know mines off that much because i got pulled over goin 79 and my cruise was set at 74.

 

the 5mph i came up with was at the 65-75mph mark. idk what mine is at lower speeds if its different or the same.

 

i put 315's on mine and got a speeding ticket doing 83 when it said 75 but also the faster you go the more it gets off! watch out for cops

 

6" lift with 35's mud terrains. Mine is off about 6 mph