Do you change all four of your tires?

tom999w said
I call B.S. on the whole tire thing. Traction this, tire computers that.... There are the same amount of cars in the ditches on the roads here in the rain and snow than there were in the 1970's, 1980's, 1990's, and 2000's; it just cost the drivers alot more to get there.

Moving the goal posts are we? How does the number of cars in ditches change anything? Oh, and what's your source on that information? Casual observation of your neighborhood?

You were whining about having to change all 4 tires, well, whether or not a car ends up in a ditch doesn't change the fact that all cars nowadays have speed sensors and ECU's that control traction, braking, etc. And the presence of those things is what determines whether or not the car needs its tires changed in pairs or all 4 at once. Whether it works or not to keep the car out of the ditch is irrelevant, how the sensors read data and how the ECU interprets it is what makes the tire height differences significant.

missing linc said
I can understand why an all wheel drive vehicle would need to have all 4 tires wearing evenly, but I don't see any reason for it with a fwd or rwd only.

Again, it depends entirely on what sensors are on the car, how the ECU is using that data, etc. In general it shouldn't matter for a FWD or RWD car, but because of advanced ABS and traction control features I wouldn't be surprised if there are FWD or RWD cars out there that are sensitive to tire height changes that could mean changing all 4. If you don't know what sensors are on the car and what the ECU is doing with that data, you may not be making a good decision.