Will this tire combo set off my ABS sensor?

[Dirty Grill]

Currently I'm running 225/40/18s in the fron and 255/35/18s in the rear. Well the rears need to be replace and I want to got to 275s. I've heard things about the ABS light comming on if the front and the rear are off by too much. In this trim the fronts would measure 78.81 and the rears 80.36 which is a difference of 1.96%. Anyone know if this will set off my ABS sensor light? Anyone else runing this configuration? Thanks.

[Dark Helmet]

I think you might be getting close to "too much" 275/30 might keep it safe.... MIGHT

[SilverStreak]

On my car, when I go to the track and mount up my Drag Radials, my ABS sensor goes off.

My fronts are 225/45-17's, diameter = 24.97"
My DR's are 275/40-17's, diameter = 25.66"

Difference of 0.69", % difference is about 2.7% size difference in diameter.

With your set up:

Fronts are 225/40-18's, diameter is 25.09"
Rears would be 275/35-18's, diameter would be 25.58"

Difference of 0.49", % difference of 1.9%

With 275/30-18's, diameter is 24.50" with a difference of 0.59"

By that estimation, I'd say you're safer with the 275/35-18's... but it could still set off the ABS sensor, not sure, though.

Also, you'd need 10" wide rear wheels, but you could run 285/30-18's, which have a diameter of 24.73" which is almost identical to the stock 245/40-17 rear tire diameter of 24.72"....