toe in alignment: tire wear vs stability

[KC Rogue]

The factory service manual for the 2012 model lists the acceptable range for toe in (whether the wheels are pointed straight ahead or veer apart (negative toe in angle) or veer together (positive toe in angle). For the 2012 model the specs are the same for front and rear tires: 0 (min) to 0.33 (max) degrees (straight ahead vs pointed in). They also give the range in the difference in distance between the front and rear of the tires: 0 to 4 mm (which seems like a lot). So why the need for toe in? Why not straight ahead? One website says "Toe in makes the car feel stable. You want just enough to give it plenty of stability."

So my questions: Is it really more stable or is it just an illusion of more stability?

Does such a wide range of the specs explain why some people get almost twice the mileage on their OEM tires as other people?

If you wanted higher tire (and gas) mileage, would it be better to set the alignment closer to 0 degrees toe in?

I just got a free "Vehicle Alignment Report" when I replaced my tires. Everything was in spec. Total toe in was 0.20 degrees in the front and 0.15 in the rear. But I'm thinking of adjusting it closer to 0. BTW, I got 37,000 miles on my Continentals driving them until the wear bars showed on the rear and I drive conservatively. Some people have reported they got a lot more miles.

[txchamps]

Tire Rack has a really succinct explanation of the ins and outs of alignment. http://www.tirerack.com/tires/tiretech/ ... p?techid=4

My gut reaction to toe-in is that whatever the increase in perceived stability, (which has to be negligible, IMHO) it does not outweigh the negative effect on tire wear on a FWD car. The article bears this out. So you and I think alike, I believe. Zero toe.

Happy driving!