I read up on what camber, caster, and toe is, but I'm having trouble understanding how this affects my driving.

So in my case, I just got a wheel alignment done:


How bad was it before I got it done? I noticed my car tended to go towards the right when I was driving; is this indicative of the wheel alignment or was it just in my head // the road was curved right?

I think it was done okay, as the current measurements are all in green (except for caster, which cannot be adjusted, apparently). But upon closer inspection, the front cambers are really close to the limit; should I go back and have them do it again, or is this okay?

 

your toe was out of spec, hence the red box. Negative toe would cause wearing on the insides. Your steering wheel might have been slightly off too

 

Toe tends to affect steering stability. The the toe is "out", any slight movement in one or both wheels will cause the car to follow a curve - so if you go over a bump, or an uneven road surface, or even a high way where heavy trucks have caused slight dents in the road surface from their wheels, then the steering will tend to respond to those bumps.

If the toe is "in", then the car won't trace out a curve, unless both wheels are turned a good amount. This gives very stable steering (which doesn't twitch as you change lanes, etc.), but sluggish steering response.

Any kind of toe will put stress on the tires as they will not be pointing completely straight - if the toe is severe, it will wear out one edge of the rubber first.

Lexus specify a mild toe in for the IS series.

--

Camber is the tilt of the wheel from the vertical.

Lexus specify quite an aggressive negative camber for the IS series (top of wheels are close than the bottom). This improves handling in aggressive cornering. As the car rolls to the outside of the curve, this rotation tilts the outside wheel, so that it is flat against the road surface.

The downside is that that the negative camber (and the toe out) tend to shred the inner edges of your tires, so you'll need to take care to check the inner edges of the front tires regularly.

The camber on the IS series cannot be adjusted.

--

Caster is the tile of the steering angle. This is a bit difficult to understand. But the effect of caster is to create camber when steering. So, when you turn the wheels to the left, they tilt, so that the left edge of the tire is pressed harder to the road surface.

It doesn't have much effect on handling, unless ridiculously bad.

It cannot be adjusted on the IS series.

 

Looks like they did what they were supposed to; you're good to go now! Toe is now back within OE specs.