Sponsored by The Tire Rack

[UncleWede]

With my Potenza slicks on the front, I was looking to get something different at a local shop. The guy was happy to sell me something else, but warned he had several complaints that service was refused by BMW because the car did not have to original equipment RFT installed. WTF?!!! I drove down the street to ask my friend at the dealership and he said that yes, if BMW traced a fault to the different tires, they would not cover the issue. I KNOW I'm going to need brake service after riding with my wife.
Anybody out there had any similar experience where a manufacturer voided warranty because of different tires? I'm not talking putting 22" Mickey Thompson mud paddles, just a decent grand touring or something that will be QUIET and maybe last until my first oil change.

[m3power13]

Those guys are feeding you a big ole' helping of doggy poo. All of the tires on our previous BMW's have been changed to something different from factory, never any problems.

[obLu]

The magic phrase there is, if BMW traced a fault to the different tires.

I can see a couple of variables here though.

1) BMW doesn't warranty tires. Therefore, by my thinking, I'm under no obligation to replace the tires with the brand or model # supplied at time of delivery. Also, who knows if that model tire will still be manufactured in 2-3-4 years? I can see them arguing RFT vs non-RFT but that would be ignorant ... obviously RFT are stiffer and would be more likely to do damage.

2) 99% of suspension components aren't warrantied anyway. They're treated as wear and tear items. Hit a pot hole, bend a control arm or sway bar link and see what your dealer has to say about replacing the parts under warranty. Don't hit a pot hole and that's what they'll claim anyway. Once the control arm bushings in the e90 start to go new BMW owners will start to discover this.

[UncleWede]

By my way of thinking, if I put the same size tire on the same rim, there should be no issue. But this claim that BMW designed the suspension around the RFT . . .??? I'm no engineer so I can't possibly think what particular characteristics might be involved, other than reduced overall weight by not including a spare. Do I change the drag coefficient by reducing by 10+ lbs on each corner? Do my brakes not stop as well, or overheat, because the rotational weight of each wheel is changed?

[Fokusracing]

Look up Magnusson-Moss Warranty Act. This is what they are referring to. This protects the consumer. Imagine if your warranty covered wheel damage. W/O runflat tires, they could deny coverage because your tires shredded and the wheel ran on the ground, while if it had runflats, it would have supported the load. Same thing goes for every other part that you change. Example: An aftermarket LSD would not void turbo failure warranty.....

[obLu]

But this claim that BMW designed the suspension around the RFT

Just means they softened the spring rates and tweaked the dampening to adjust for the stiffer "spring rate" of the harder tire sidewall. No magic.

Breaking, ride, handling, acceleration are all better as a result of lower unsprung weight. But the weight diff between non-rft and rft tires really isn't all that much. They just have softer sidewall.