I'm taking the 2007 Prius in this weekend for a set of Nokian WRG2 in 185/65-15 size. I'm going to have alignment checked at the same time. Is there an alignment spec that you guys recommend? My priorities are stability first and fuel economy second. We're starting to carry stuff on the roof (kayaks, pod) and I want to have a stable car especially in windy conditions. The only other car where I've cared about alignment is my Porsche. There I had the fronts set to toe-out with maximum camber, the rear set to toe-in with maximum camber, this was for auto-X purposes, and I cared not at all about highway stability. But the Prius is our family hauler, not an AX machine.
Only PART of what works on a standard Solo II set-up doesn't, as you have indicated, work on a street car. The Prius spec, as I recall, is for zero to slight toe-in. I know from experience that toe-out isn't a good thing for stability, making the Prius darty and more succeptable to following rain grooves (although tires seem to have more effect on the latter). I also seem to remember the Prius calls for a little negative camber, which is good on the street and on the track (although for the track, more is better - we ran 2 degrees negative camber front on our Neon ACR). Caster depends a lot on front end geometry, although from a pure theory standpoint, positive caster reduces straight-line stability and makes turn-in quicker (good for the track) while negative caster increases on-center stability and increases turn-in reaction time (good for the highway). In any case, I'd go with stock (which I did on mine) with critical attention paid to getting the toe-in at zero or VERY SLIGHTLY in (less means less wear). It made a world of difference on mine. Also set the camber to the negative limit of the spec.
