what to adjust for speedo???

[newguy2diesel]

i have 35" tires on 18" rims and need to calibrate speedo. the abs light and brake light is on i believe due to this. any help would be great!!

[newguy2diesel]

i know someone in here has done it, does the speedo calc in the tune actually work??

[newguy2diesel]

thanks for the help guys

[joecar]

i know someone in here has done it, does the speedo calc in the tune actually work??

It should... but it won't clear your ABS and BRAKE lights (these are controlled by the ABS controller).

Enter your tire diameter and see what it does, save to a new filename (save a copy of the old file)...

Your revs/mile should go down by the same proportion that your tire diameter goes up.