Where can I find wheel alignment data?

Easily sorted, you can convert it into degrees pretty quickly. Just use (and make sure the calculators set to work in degrees not rads):

sin(wheel diameter in mm / toe measurement in mm)

inverse sine * (toe measurement in mm / wheel diameter in mm)

For instance a 15" wheel's 281mm diameter, if they say 2mm toe out then that's

Sin(281/2)=0.63deg toe out, or 0deg, 38min if you'd rather.

inverse Sine (2/281) = 0.2 deg toe out, or 0 deg, 12 minutes if you'd rather.


(What a tit, I got it wrong, teach me for trying to be smart while half asleep! )

Haha, it looks a little daunting, but it really is easy, just a couple of button presses on the calculator. Anyone given the formula can manage that regardless of their aversion to maths.

I guess if you're not so bothered about accuracy then you could say it's very roughly 0.3deg per mm (or 20 minutes). It'd probably be accurate enough for most road cars. Still, a little trigonometry never hurt anyone, and most of us should know the basics for GCSE/O-levels.

Conversions are an unfortunate pain in the backside working with cars in this country. I've got 185mm wide tyres, pumped up to 34psi, fitted to 15" wheels, over 280mm discs with 50mm pistons in the calipers, fed by a 3/16" brake line.... etc. We're all used to working with silly measuring standards and converting between them, a few geometric conversion's have to creep in there sometimes, and they shouldn't be too much of an issue when they do.

Yeah, ignore what I said, half asleep today, if you did it my way and calculated it, it's:

Inverse Sine * (toe setting in mm / wheel diameter in mm)

Which yeah, for a 15" wheel would come out at 0.2 deg or 12 minutes per mm. What is actually a 'mm' of toe is pretty poorly defined though.