"dont get bigger tires... it will throw off your speedo", i beg to differ Options

[lagos]

so, for years ive always had people say to stay with low profile tires, because anything bigger will throw off your speedo. im sure we've all seen the online calculators and countless threads. ive even had tirerack call me back and try to convince me to change my order from 225-45-17s to 205-40-17s because of this..lol ...

well anyway, i just wanted to say that all that, is mostly a myth. i recently got a gps for my car. my speedo is dead on with the mph reported by the gps. i was a bit shocked because i expected it to be off by at least 1-3mph. so go ahead, get bigger tires and enjoy the ride quality..your speedo will be just fine

This post has been edited by lagos: May 24, 2007 - 9:25 PM

[x_itchy_b_x]

its not a myth. its fact, larger tires = more radius = the ecu doesnt know any better and its going to affect the speedo because the sensor is getting the speed reading from the tranny and not the tires radius. it affects you less at lower speeds because its more of a ratio and you more the faster you go.
it wont affect it like a truck going from 33" to 38" tires, my old truck was over 10mph off on the highway.