Hey guys (and girls), I've got a scary thing going on here. About a week ago I noticed that my rear tires were bald and my fronts were showing camber wear on the insides of the tires. The car is lowered so I decided that I'd go ahead and get an alignment done to preserve the life of the fronts a bit longer. The alignment brought the front and rear fairly close to OEM spec. I was running a set of relatively expensive BFGoodrich g-Force (directional) tires on all four corners and decided to save some money by going with the cheaper but well reviewed General Exclaim UHP (directional) which had a much better tread wear rating (I ran through the g-Force tires in less than a year). I got two of the GE UHP's to replace the rears and had the tire shop swap the fronts so that the unworn side is now facing towards the inside. After all this was done I noticed a few things that were out of the ordinary. There is a fairly strong vibration felt in the steering wheel around the 65-70mph mark on some types of pavement which then goes away on smoother pavement but returns around the 75mph+ mark and continues to vibrate harshly past 90mph (I had to check to see if it just happened within a certain range as would happen with an unbalanced wheel). More alarmingly, there is a curved portion of freeway towards my house which I've easily taken at some very high speeds without issue but with the current tire configuration even at 65mph the cars traction control intervened three times during a very short stretch (maybe a good 3 seconds in total). After paying more attention to how the car feels, it seems to be significantly more twitchy through any curved portions of high speed road and having the traction control kick in through a corner is pretty damn unsettling by itself. Anyone have any ideas? I've driven vehicles with mismatched tires in the past without any noticeable difference in drive ability. Could an unbalanced wheel cause such an issue? Would the camber wear on the front tires play a role here (even though the unworn side is making most of the road contact after the swap)? The car felt perfectly fine prior to tire swap.

*EDIT* Just to be clear, the fronts were dismounted and swapped left to right so that they face in the correct direction.

 

it might not be balanced correctly.

 

trying going to a different shop, there's always some error in machines or mechanics. Also have them check all the bolts, they might be loose which may shift any recent alignments made.

 

Check balance, air pressures, lug nut torque, and wheel hardware (if they are aftermarket wheels).