So I just put on a new set of staggered wheels, they are 18x8 with 225/45/18 tires in the front, and 18x10 with 235/45/18 tires in the rear. I can't remember the offsets for my new wheels though.

The diameter for the front and back is almost identical with the stock wheels and tires, so my speedometer isn't off at all.

However, I noticed that since I put the new wheels and tires on, the car pulls slightly to the right on the highway, leaving me to steering a little towards the 11 o clock position in order to go straight.

Currently I'm running the PSI at 35 all around when cold.

I looked inside the door jamb and I believe the recommended PSI is 33 for the fronts and 30 for the rear, but that's for 225/45/18 tires.

I know I'm going to get mixed responses on this, but what do you guys currently run your PSI at if you have aftermarket wheels/tires?

I swear when I took the stock wheels/tires off the PSI was at 40, but I had no alignment issues.

 

well, both your stock and aftermarket wheels are 18s so the speedo should be the same either way regardless of width... but unless youre running a ridiculously high or low PSI, i doubt it would have any effect on pulling left/right while driving. Are your tires directional or symmetric/asymmetric tread? If you have directional and they are on the wrong side of the car it might cause pulling...same with the symmetric/asymmetric tread design...

 

I'm running 37-PSI in the front and 33-PSI in the rear for 255/35ZR19's on 19X9 wheels all the way around.

 

Pix?

 

I build tires for a living, so here goes.... BTW Mystic is dead on.
1) If the alignment is not off and tire pressures are the same, the car should not pull left or right drasticallly.
A trade tire may be allowed to have as much as -30 to +40 lbs. of force during speed testing. O.E. tires at my company generally have less than 10lbs either way, if it exceeds that limit it is a trade tire or repaired to spec. Trade tires are what you buy in stores...
Conicty is just what it sounds like, the tendency of the tire loosing it's shape in one direction or another causing the tire to pull. This will without a doubt cause a car to pull in one direction or the other.
Chances are one or more of your tires has a conicity rating above or below specs. Now in general, aftermarket tires are no where near the quality of O.E. tires. Tolerances are much tighter, down to 1/2mm's!!!
Conicty is just what it sounds like, the tendency of the tire loosing it's shape in one direction or another, This will without a doubt cause a car to pull in one direction or the other.
Pretty much you got a hold of a crappy tire or tires. I hope not but sounds like it.
Take it back to installer's shop if possible. Tires should be inflated to tire manufactuer's spec which usually falls into the range of the car's spec inflation.

 

thanks for the replies guys. The set of tires i bought are Kumho Ecstas, brand new, and they are uni-directional. They are all rolling the right direction, I have personally inspected each tire/wheel individually and everything appears straight, no bends, no cracks, nothing. But if it is in fact Coincty like you say, then I suppose I wouldn't be able to tell unless I were to see my car rolling at highway speeds, right?

and a pic as requested for greenbeans

 

Love the wheels man! The conicity issue is not something you can see. It is measured on a machine at tire factories only. You will have to swap out tires to verify. Whomever sold you the tires should warranty them. Explain to them you have eliminated all other possibilites and you have a "plysteer" issue and you are highly unsatisfied. If this is truly your problem, the suspect tire or tires are trash and need replaced. The #1 cause of this is offcenter belts or tread. Once a tire is cured, it is nonvisible to the untrained eye.