Speed Difference

[Flipn]

I haven't taken the time too peek at my diff tag but I believe I have 3.73 gears in her and was wondering what is the difference at 100kms/60mph with goin from the stock 16" rims with the 70 series rubber to a 26" rim with 30 series tires? Theres probably what a 2-2.5" overall diameter difference so would that throw it out 10kms pr hr? becaue thats what it feels like

 

[radkon]

If you post the complete tire sizes I'll calcualte it for ya.

Tread/sidewall diameter

IE: 255 / 60 R19 to 275 / 70 R20

 

[JKmotorsports]

This will tell you the difference in speed and will give you dimensions of diameter, tread width, etc.

 

[Flipn]

305-30-26

 

[radkon]

Well if you are running 265/70 R16 and want to move to the 305/30 R26 you will have a +27% error in your speedo. The acceptable limit is +- 3%. You'll definately need your speedo recalibrated. Otherwise you'll see the following:

Speedometer reading/ Actual Speed
25 MPH / 31.76
35 MPH / 44.46
45 MPH / 57.16
55 MPH / 69.87
65 MPH / 82.57
75 MPH / 95.27
85 MPH / 107.98
100 MPH / 127.03

 

[01lt_hoe]

all of the calculators I found on the web stop at 20 inch rims... how about 265/75/16 to 305/35/24

 

[Flipn]

yeah so just like i thought it was about 10kms diff at 60mph

 

[Flipn]

Thanks I really appreciate the homework

 

[radkon]

all of the calculators I found on the web stop at 20 inch rims... how about 265/75/16 to 305/35/24

The 305's are 18.38% taller so your speedo will read:

Speedometer reading/Actual Speed
25 MPH / 29.59
35 MPH / 41.43
45 MPH / 53.27
55 MPH / 65.11
65 MPH / 76.94
75 MPH / 88.78
85 MPH / 100.62
100 MPH / 118.38