Rumor of tire replacements on the new body 7...

I read in an auto magazine where tires are being replaced way before worn due to strange issues. Sadly, they aren't being warranted. I'll try to find the magazine, but was curious if anyone has heard of this.

Not sure about an article... but read this blog:
http://blogs.insideline.com/roadtest...2009-bmw-750i/

3 tires in a month or so...

Page 20, Autoweek, February 22, 2010. HIGH-SILICA DIET, by Jonathan Wong

"...Of the four dealer trips, two were for reasons that had become common in the first quarter: to replace front tires for broken belts. We had to replace both front Goodyear Excellence run-flats on separate occasions. The updated tire count shows us rolling on the fourth right front tire and the second left front tire, to support the notion of the tires simply being inadequate to handle the BMW's curb weight."

I am finding more information to support this accusation on the web. This is disturbing. Note: THESE ARE STOCK WHEELS and TIRES.

Quote:
BMW aims to provide our customers with a premium product that provides ultimate safety with optimum performance and it is always a concern to receive feedback of this nature.

We chose to include Run-flat technology on our vehicles for the following reasons:
It is dangerous to stop on any road to change a tyre, especially on a motorway or at night.

There is no need to have to wait for a breakdown service to arrive.
Safety and security of the driver and passenger(s) is maintained.
Alloy wheels are difficult to detach from steel hubs.

On most cars the spare is under the contents of the boot, and uses boot space.
It can be tricky to line up the wheel bolt holes with the hub screw holes and match the thread.

The dirty punctured tyre needs to be removed and stored in the boot.
Another puncture before the punctured tyre is mended means one is stranded.
A driver can continue for 150 miles at 50mph with a punctured Run-flat tyre.

All of our vehicles that use Run-flat technology have their suspension and braking components set up to accommodate Run-flat tyres. Should you decide to change to non Run-flats, it may alter the driving and handling characteristics of your vehicle. It is for this reason that this modification is not recommended by BMW as a manufacturer.

However, it is possible to have standard tyres fitted. You will additionally need to purchase either a spare wheel with jack and brace set or a mobility kit which can be ordered from the Parts Department of your nearest BMW Approved Dealership.
End quote

The tire's construction is so vastly different. I am surprised to see so little support in the runflat. I suppose it isn't necessary given the ever present support system of plastic braces.

Personally, I liked having a spare and having normal tires. I can see why BMW would do it though; most drivers in the income category buying these cars are probably highly unlikely to ever change a flat, I suppose. I guess I'm one of the exceptions.

They don't appear to be abandoning it anytime soon.

Tire wear sensor is annoying.

I have replaced a front tire on my 09 750li...pothole...but what I consider a minor pothole. It was certainly not a monster and tire should have easily handled it.

Interesting, the runflats are one of the things holding me back. I've driven three differnet 7 series over the past 13 years, a 2001, 2004, and now a 2007. I've never had a flat. In fact, we haven't had a flat on any car in over 20 years here in AZ. Replacing several for pot holes would really tick me off.

Originally Posted by briansbimmer

I have replaced a front tire on my 09 750li...pothole...but what I consider a minor pothole. It was certainly not a monster and tire should have easily handled it.

What tires/rims do you have? Stock 19's?

I have a strong sense that these run-flats are not as durable as a normal tire.

Well....I have the sport package, so whatever came stock on those. I know they are 19". To lazy to go down to garage and look.

I hope my Pirelli P Zeros runflats hold up well

Originally Posted by briansbimmer

Well....I have the sport package, so whatever came stock on those. I know they are 19". To lazy to go down to garage and look.

Yeah, that's what I have too.

I do know the factory 19" come with 275/40 and 245/45

I don't think the tires are as thick, on the sidewall, as a normal tire. And I believe this lack of support gives a bad ride. Not to mention, if you do hit anything with your runflat, it damages more easily as there is not a large air pocket for absorption that would be present with a normal tire.

The trade-offs are significant, but in the interest of saving lives who can fault them. I do think the ride will improve as they get better at making these tires. However, I am not willing to go without a spare and frankly, I don't have room for it, nor do you really. So we're stuck with run-flats.

In considering new wheels, I've run through just about every rim on the planet. Why is it there are few good looking rims for the BMW. I see so many nice wheels for the Mercedes and Audi. And of course you have to weigh the cost and the selection of wheels available for larger size wheels. At 20, a decent selection, at 21, you're in trouble--two or three brands. The cost is crazy as you go larger, too. And good luck getting replacements if you have a flat on the highway somewhere. Yeah, you can drive on them, and you're going to have to find your tire.

I haven't committed to anything as I don't have enough information to make an informed decision regarding replacing the current rims/tires, so I sit. No spare is out for me, though.

I would have gone 20" but because I travel twice a month across to Malaysia and the last thing I would need is blowing up my tyre on the highway. Hence I stuck with 19", more reliable. Honestly speaking it was a very smooth drive with the runflats, I took it up to slightly over 200kmhr and held it there for a bit.