How practical are run-flat tyres?

[Toffeeman]

I was at AB Sg Besi last week looking at the new CKD E90 models. One of the things that struck me re: E90 is that there are no spare tyres and also no space available for spare tyres. This is on grounds that E90 runs on run flats. Apparently, BMW insists that as a policy and no choice for customers. Frankly, I thought BMW should not 'force' the run flats down the throat of the consumers especially in the context of Malaysia. My views of run flats are as follows. There are many disadvantages: 1. Expensive2. Not comfortable as it will make the ride unncessarily harsher3. More importantly is that how many of Malaysia's tyre shops will stock run-flats? This means even though I have 150km to run in the event the tyre punctures, I may have still go back to AB for replacement as there are not many available in the tyre shops. Given this in mind, I really feel that BMW Malaysia should not be so 'arrogant' in pushing the run flat tyres down our throats. What do you guys think?

 

[safri]

i don't think it's BMW Msia call...new model new technology ma...same goes for 1 & 5 series...unfortunately, the initial buyers would have to endure being the guinea pigs..

 

[Toffeeman]

Apparently, the E90 unlike the E60 does not even have a space for spare tyres. This means, one will run the risk if he changes to normal tyres after the run flat tyres are worn off. I think that is not fair to the owners.

 

[3er]

I love the concept behind it. I wouldnt want to be caught with a flat on a deserted highway at midnight when its raining a storm. Technology will improve, prices will drop and it will be more comfortable. Just give it time to mature.

I've had more punctures in KL in the same number of years i've been driving in Oz and UK. I would really appreciate runflats.

 

[valkryie]

The runflat can be repaired just like normal tires. So if you have a puncture it does not mean you will have to replace the tires. But the cost of maintaining the new E90 with run flat will be very expensive at RM 2000 per run flat tires.

You can modify the boot to hold a compact spare tire if you wish. Involves cutting up your boot. This info was convey to me by AB sales person. Not sure how true it is but logically should be ok.

Like 3er says give it more time, prices will drop. Just like plasma TV.

 

[KL2DC]

My views on RFT...

1. Agreed RFT is a half baked technology that is being 'pushed down' our throat. Half baked in a sense that they are heavy, hard riding, not much choice for replacements, high price and in some case supply/availability issues.

2. Despite BMW's claims that the e90 suspension set up is optimized to run RFTs (read softer setting to accomodate higher unsprung weight at each corner), a switch to regular tires have in most cases resulted in faster acceleration, better economy and better response and handling. Btw your RFT and wheel combo weighs about 50-60lbs at each corner. Have you lifted your RFT tire/wheel combo lately?

3.The benefits are huge. You have increased security and convenience. No more late night by-the-highway tire changes. Also effective in avoiding dangerous high-speed blowouts. Also, supposedly doing away with the spare tire helps in maintaining the 50:50 weight distribution along with the trunk/boot placement of the car battery.

4. RFTs can be patched in most cases as long as a) the RFTs were never driven with zero pressure for extended period of time b) the leak/failure is because of sidewall breach. Please note that only qualified tire shops can handle RFT because of their tire bead design. Some experience, skill and equipment is necessary to mount RFT tires.

5. There are some options for those who choose to run regular tires: 1) latex sealant and pump combo kits work well. Make sure to get a good set up for easy wheel clean up when replacing tire. The OEM //M Mobility kit (std in the //M cars) work well (about USD120). But there are alternative like Continental kit etc. 2) You can always lug a full-size spare in your boot/trunk for long trips.

6. E90 does not come with jack and tools set. Also a special jack is required due to rectangular plastic jack mount template points on the undercarriage. A regular jack can damage these plastic points and can be unstable in holding up the car. OEM jack/tools set cost about USD100.

7. So far, there is no effective space saver solution yet. Aftermarket e46 fitment space savers does not clear the brakes (offset issue). Also and especially on the 330i e90, BMW does not recommend the use of steel wheels/rims due to heat issues with the brakes. Alhough, I have seen one person who claimed that he found an OEM donut that works. Not sure from which model.

8. I would not, under any circumstances, cut the trunk/boot floor of my brand new e90. One of the better solutions I have seen is to fabricate (think stereo shops and subwoofer enclosure) a shelf/dummy stepped floor to house the spare tire. Although this cut into trunk/boot space.

9. Here in the US, dealers offer full RFT tire/wheel insurance.

 

[shuksE90]

Only when I got my car that I began to understand why all the E87s in the world run on RFTs. No space - even for a wheel-barrow spare. Unlike the saloons (where the battery is placed at the sides), they don't have large enough space at either sides (even the First Aid Kit barely fits). Because of this, they supplied RFTs, and placed the battery in the centre well.

In my case, the car came with sports suspensions and 18" rims, so, fitting RFTs will only make the car heavier, and harder bumps (and possibly a few expensive visits to the chiropractor from all the backaches too! heheh) So they compensated this by fitting normal tyres (Michelin Pilot Sport Deux) and threw in a whopping RM550 Conti tyre patch kit for free. After all, the TPM will still indicate so that they're not damaged in case there's a loss of pressure (Cheh, sounds like the safety announcements in airplanes eh? Haha) Of course, the downside is that you'd still have to stop and get out of the car and run the patch kit. But according to the manual, using tyre patch kit lets you drive further up to 200kms at a max speed of 50mph or 80km/h (compared to a max distance of 150kms with the RFTs? if i'm not mistaken la). Good eh? Especially when you get caught in the London Orbital (M25), not realising that you've passed the same exit 3 times around

True enough, it rides superbly and tucks corners in as if the tyres are sticking to the tarmac! It's no wonder the M3s and M5s are never fitted with RFTs as standard (not yet, anyway).

Kind regards,

Shuks

 

[1+2=3]

i think its quite common for UK owners to opt for conventional tyres over the RFT. their main reason is the uncomfortable ride. KL2DC, apparently, their dealers there can help to install a space saver spare without any cutting in the E90.

but i think the idea behind run flats is great. i'm sure eventually, the technology will be refined further.

 

[RedZ4]

Run Flat Tires- RFT aren't that bad. The idea that BMW has is that if something happens, i.e. a puncture, you'll still be able to drive to a nearby location to have the tire replaced.

The RFT may not seem too practical in this country as many tire shop don't stock these tires. But then again, if you drive a E90 with the sports package, most shop don't even stock those tires.

RFT also offer space and weight saving on a vehicle. If you want to change out the RFTs for normal tires, do so, but if you're caught with a flat, you might have some issues getting a replacement. You're car will probably need to be towed back to the dealership. And if I'm not mistaken, most of us that have newer BMW models with RFT probably have the BMW road side assistance, right? So no worries.

In my case, I have been on the fence about replacing the RFT but if I get a flat, I'm screwed and have to wait. With RFT, I can probably drive somewhere to get it fixed. I can't even carry a spare tire in the trunk. So the performance of regular tires does not outweight the security the RFT.