Left front toe was out 0.29 degrees. Fixed. Rear left toe is out 0.31 and right rear toe is 0.29 Rear camber left is -1.3 and right is -1.5 The alignment shop said the rear wasn't worth doing as .3 degrees wouldn't hurt fuel economy that badly. I don't know if I believe that. So the question is, since I could fix the rear alignment myself with the two ez shim kits I bought, would it be worth it. It will take my about an hour per axle doing the labor myself. I have all the necessary equipment including an accurate torque wrench. I bought the lifetime warranty at Firestone and can have it rechecked as often as I like, so it won't cost me anything except time to check my shim work. What is the *ideal* alignment? Why is the toe range .03 to .28? Why isn't ideal 0? What's ideal for camber? Using the ez shim: http://www.spcalignment.net/instructions/75800-INS_WEB.pdf I'm thinking left -0.25 toe adjustment 0 camber adjustment (chart says use 19/1). This would leave me with camber -1.3 and toe 0.06. On the right, -0.25 toe adjustment and +0.25 camber (chart says use 37/14). This would leave me with camber -1.25 and toe 0.04. Any thoughts?
The spec for total rear toe-in is 0.30 degrees +/- 0.25 degrees. The spec for rear camber is -1.5 degrees +/- 0.5 degrees. You asked why the ideal toe-in isn't 0 degrees. I believe that moderate rear toe-in improves vehicle stability at highway speed. If you are going to make adjustments to your rear wheel alignment, I would suggest focusing on reducing the toe-in to be around 0.15 degrees on each side, and leave the camber as-is.
My Firestone store just says that adjusting rear camber is impossible, when they mean they do not perform that work. Toyota has a range for each measurement called in spec. It is an interesting question how much fuel economy can be lost at the edges of the accepted range. My guess is -- not much, since we are talking about fractions of one percent.
The next index of adjustment is 0.19 degrees which would put the rear toes at 0.12 and 0.10. -1.5 camber on the right is really more than I'd like. If it were on the left I might leave it like that as I tend to corner hard on clover leafs. Also, camber tends to become more negative over time as springs sag although my camber front and rear is *identical* now at 60K as it was at 10K. If I'm going to adjust toe at all, there's no reason to not even up camber as well. Dealer at 10K and Firestone at 60K both show identical readings for front and rear camber and caster, so I'm betting because of the consistency that the alignment racks are pretty good these days. I'm tending to agree with you that trying to hit closer to the middle range might be better. Trying to get it as close to 0.03 might result in stability issues *especially* if I overshoot without knowing it and hit 0 or even negative toe in.
I wouldn't worry about it Sorka. My rear left toe is way out of spec at 0.48. I've been driving with it for ~6000 miles and no change in mpg and I can't feel a difference in handling. Just keep up with those tire rotations!
