Speedometer Setting

[lplott]

If I recall correctly, the pulldown table does not go up to 335 for tire size, so can you enter the tire size manually?

Lonnie

[Blacky]

If I recall correctly, the pulldown table does not go up to 335 for tire size, so can you enter the tire size manually?

Lonnie
Just type in 335 into the drop own list.
Regards
Paul

[SSpdDmon]

Or you could do the more accurate thing and measure the tire height with a measuring tape. My stock tires 275/40/17 are really 25 inches tall...not 25.66 inches.

[joecar]

Or you could do the more accurate thing and measure the tire height with a measuring tape. My stock tires 275/40/17 are really 25 inches tall...not 25.66 inches.I agree.

[Blacky]

The most accurate way to set up your tire/speedo calculations is to measure the rolling circumference and back-calculate the appropriate diamater as follows:

1. Inflate tire to the correct pressure.
2. Mark the tire wall at the bas of the tire.
3. Mark the road at the base of the tire.
4. Roll the vehicle until the mark in the tire has completed exactly one revolution.
5. Mark the road again.
6. measure the distance between the two marks on the road. That is the rolling circumference of your tire.
7. Calculate the correct tire diameter using this formula:

diameter = rolling circumfernece/pi
where pi = 3.1415926536

i.e. if your rolling circumference was 83.25 inches, then your tire diameter will be 83.25/3.1515926536 = 26.5 inches.

Regards
Paul