Track Prep - Alignment/Tire Conundrum

[MonacoMurphy]

Hi all. So I'm headed to Watkins Glen at the end of April and I'll be getting an alignment. I have a bit of a situation though and want to hear your thoughts.

F80 has 5k miles on it currently. About 1k miles into ownership I hit a nasty metal plate which ripped into my left front tire. It was Memorial Day weekend and I didn't want to be stranded so I went to a small tire shop ordered a new tire and went to the park while they fixed it. When I got back it was the wrong, non-star spec, MPSS. As I was with my wife and infant I said oh well and left it as is- we're 4 hours into the debacle by now.

So my question is, I'm going to get an alignment and I'm wondering if it's going to work. Currently it pulls to the right and if I turn the wheel to the left it bounces back to center quite aggressively.

The options are to just align it- which I prefer cost wise. Or to replace the tire, but that creates an issue where one front has 5k miles and the other is new. So then should I replace both fronts, to which I would want to put on the new MP4S and that screws up the front to rear equation both grip and mileage wise.

What would you guys do?

[MRV99]

There are threads commenting on a common right pull problem on these cars but I think that until the tire issue is investigated it's hard to say

It is known the the star mpss are different than standard mpss. They do have slight differences in tread width and I believe RPMs. I don't know what your appetite for swapping wheels are but the first thing I would do is swap the right/left front tires. I assume you had the flat on the front. If you find the car still pulling hard to the right then there are deeper problems. If it corrects itself or pulls left, it points to a mismatch tires.

If the problem changes with swap then you have to decide if you want to put matching non-star mpss or BMW mpss on the car. The good news is there is always a market for mpss tires star or non-star.

If the swap does nothing then you may still need to match up the tires and get an alignment. You would need to research the exact specs of star vs non-star mpss in the same size to see if that could be a factor

[CanAutM3]

There are significant differences between the BMW star spec and generic 255/35R19 MPSS. The generic one as a wider contact patch, a squarer contact patch footprint, sits squarer on the road and has a greater land-see ratio. I am not surprised you are getting odd behavior (pulling to one side) with mismatched fronts. I would recommend you change the odd tire, especially if you're heading to the track.