Tire Selection Conundrum
 

I have a 2010 535iXT with about 55k miles in the USA. We recently noticed a road feel/light thumping. Further inspection showed the rear tires were substantially worn down on the inside, although the rest of the tires' area were rather normal with good tread left.


A, Does anyone else have any experience in this area?


B. I have perused the forum for information on tires. It appears Michelin Pilot Super Sports and the Continental ExtremContact DW are a good match for my type of driving in this car. We live in FL, so easy to avoid snow... and this is my wife's BMW wagon. The car currently has OEM 17" wheels and 225/50s on it all around. Problem with Michelin PSS don't come in that size. The manual also lists 245/45 as an alternate. That would be almost an inch wider and .2/10ths of an inch shorter.


C. Anyone have prior experience or advice in this arena?

Hmmm... You have run flats on now I assume? You want to stick with them, or go regular? With my 3 series, because of the camber in the rear, and the RFT's especially, they were known to wear more on the inside, but I'm surprised to hear that on your car. Get your alignment checked for sure IMO and back out the camber if that's the cause.

Just use a tire calculator like the one at 1010tires to see if changing tire sizes vs. the original size will have an impact. You can get away with up to a couple of % difference in the diameter/height of the original tire.

Tire/wheel selector calculators are all over the web...some are better than others but most give every detail about the differences to allow you to make an educated decision. That being said, tire sizes are not a standard. One manufacturer's 245/45 could be thinner or wider than another's. So once you pick the size, go to each manufacturer's tire's specifications and look at actual widths/sidewall heights.

As for a tire recommendation....I currently have Michelin PS2s on my 530XiT. I had Michelin PSSs on a previous vehicle and I can honestly say I didn't like them. They're an amazingly sticky tire but I really believe that they're designed to go on wheels where the sidewall is in the 25 to 35 range because in the 45 that I had them, the sidewalls were WAY to soft and it gave my wagon a bizarre 'soft and unplanted' feel rolling up the highway at speed. When pushed on corners they were crazy sticky but just didn't like the feel. Instead, I would recommend the Michelin Pilot AS3. Yes, it is an all season tire, but it is still remarkably sticky and felt much better on the road. The PS2s I have now were not my choice so I have to live with them for now but they too have a soft-ish feel that I'd just assume not have.

As for any tire-wear issues, be sure to find a good alignment shop (they're not all created equal). Here in GA, we have Butler Tire. They stand above the rest when it comes to tires, tire care, and alignment.

Not sure if any of that helps....but it's my 3.25cents worth.

-r

Thank You
 

Thanks Lotus and OCLVFrame (hope I got that right). I had already checked the tire calculators, but as one of mentioned, the actual sizing isn't quite as standardized as one might hope. It was interesting to note that the BMW Manual only stuck with the 225/50 and 245/45 sizes for 17" wheels and 245/40 for 18" wheels on our vehicles. Sometimes the aspects of the vehicle we love, such as it being a wagon (therefore a bit heavier) and all wheel drive (with increased offset) make things a bit more complicated.


We had the Conti ExtremContact DW on our 2006 530iXT after replacing the OEM type runflats. What a big difference, and I can actually say we loved them. So much better performance, but the real thing is how much quieter the car became.


The current wagon ( 2010 535iXT) currently has Goodyear Eagles (non-run flats) on it. The ride seems louder than the Contis were, but not as bad as the OEM RFT on the 530 were.


The sidewall to footprint aspect for the PSS is a good point. I don't need a seriously improved, track-ready performance aspect... I do happen to have a 2001 M5 for that type of fun. But I like the higher performance aspect in dry and rain for emergency procedures.

Interestingly enough, the local BMW dealer's price on wheel alignment was cheaper than the discount tire company, which is also well rated for service. I do plan on staying away from RFTs for now, although it does sound like they are getting better.

Sure, technically each mfr's tire could be a bit different than the other's, for the same size, but does it really matter that much for our cars? I mean, for a sports car, especially one that's lowered, maybe.

I've got the PSS's on my 3 series, and really like them.

For the 5, I wonder if the stiffness of the RFT's in the sidewall when going to the PSS's which are non RFT's, is what you were feeling partially, when you say they're soft.

I went with the Continental ExtremeContact DW for a 30% cost saving. The Michelin PSS were not made in the exact size I was looking for, and I figure I might be looking to go to an 18 or 19" wheel later, so better to stick with what worked good last time, and see what happens in the future.