Wanted to take the car for an alignment to Firestone since they have the lifetime deal. But in the pass, I just trusted the tech and their computer (when it's all green)

But I want to make sure they are using the right specs....what are the right specs for a 2007 IS-350? Sport package with stiffen springs...but not slammed or anything. 18" wheels. So more or less spec.

Thanks.

 

Unless I'm mistaken, the specs for the factory setting will be the same as for a car that is lowered and on different springs. The geometry of the suspension has to be the same, regardless of whether the car is lowered. Whoever is doing the alignment will have to adjust your car's suspension, so that it has the same settings as it would have if it were at factory settings. The wheel and tire must be centered at the correct angle for caster, camber and toe. This is the wheels angle (left to right) which ensures the tire is flat on the ground (camber). Also that the wheels are perfectly parallel to each other (toe), and that the wheel assembly is at the correct angle vertically (caster). A lowered car should be adjusted so that it meets the factory settings for a correct alignment. If you have lowering springs, this should be achievable with the adjustments that are on the factory suspension. I do believe that you may need a camber kit to get your car to factory specs if you have installed coilovers that drop your car more than an inch front or rear. I'm sure there is more info available on this in the suspension forum.....