I bought a new car about a month ago and I’ve noticed that the tires seem to be angled slightly in. That is, rather than forming a 90[sup]o[/sup] angle with the road they seem to form something more like a 93[sup]o[/sup] angle with the top of the tire closer in to the car than the bottom of the tire.
I have not actually measured anything or used a level to determine if this is really the case. I suppose it could be an optical illusion of some sort given the shape of the car or something. Still, when I look at other cars their tires seem straight up and down. Given that my car came from the factory like this (I assume) I can only hope that this is normal for my car but I thought I’d ask here and be certain. If it is normal (is it?) is there a good reason for this or just something they do for no apparent reason?
It’s normal. That’s what they set when you get your alignment done. Different cars have different alignment specs. There’s three measurements; toe, cast, and camber. One of those is what you’re seeing. (Hey, IANAM and I too lazy to look it up)
My car is an Infiniti G35 if that helps (to answer RSA’s question).
I have no idea if my car has independent suspension. All I saw on a quick glance through the Infiniti web site on this model is “…a newly developed four-wheel multi-link suspension system”. Don’t know if that tells anyone anything or not.
That one is camber. It can be either positive or negative, depending on whether the tire tilts inward at the top like you have described (negative) or outward. Look more closely at other cars - as already indicated, specs for alignment on various makes and models call for various degrees of camber.
My WAG would be that it would aid in fast cornering, where the centrifugal force of the car going around a corner would allow the tire to approach 90 degrees instead of starting at 90 and being taken well past that.
It may well be normal. Negative camber, which is what you have described, tends to enhance cornering. Usually, however, it’s just one degree or so off of vertical and not obvious to the naked eye, which raises the question whether yours is off. You can get an idea by looking at other G35’s on a new car lot, but the only way to be certain is to measure it on an alignment machine.
Indeed, your car does have independent suspension. In addition to any negative camber, there may be another reason that the tires look so “tilted”. Do they always look that way?
For example, say that you pull rapidly into an uphill driveway and stop quickly and then apply the parking brake. The suspension was compressed when you hit the driveway causing additional camber in the tire geometry. Because the springs are not strong enough to drag the tires into a vertical position, they will appear quite tilted while parked. You can check to see if this is what you are seeing by driving at moderate speeds on a flat level surface and then gently coming to a stop. You may see that the tires look much more vertical in this case.