bigger tires change gearing?

[macman]

what tire diameter can the vibe handle? I am wondering if a bigger tire will increase the gearing and provide lower revs on the highway yielding better MPG?any thoughts?

[Raven]

Most tire websites recommend staying within 3% in tire diameter. Of course your speedometer reading would be off also.

[Mavrik]

it can also throw off your abs if your Vibe is equipted with it.

[joatmon]

I would think tire size would only affect ABS if you had different sizes on the car at the same time, but I don;t see how it would affect ABS if they tires were all the same size. ABS works on differences between wheel speeds, not absolute wheel speeds.

[Mavrik]

the system also monitors vehicle speed and if that reading is thrown off... so can the ABS. I've never seen it on a Vibe but I have on other vehicles. I'd imagine it works the same.

[joatmon]

well for me the issue would be the speedometer calibration. It seems like when power is first applied to the instrument cluster, the speedometer and tach go through a calibration sweep. I don't know how to recalibrate the speedometer for different gearing/tires. I rely on my speedometer being accurate to keep John Law from inviting me to participate in the judical branch of government.