Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 26th August 2009, 20:43   #1
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,175
Thanked: 128 Times
Default Run Flats could go Flat

Recently read that after settling a lawsuit with disgruntled owners of Michelin run-flat tires, Honda has dropped the run flats for the 2010 model year in the US (and worldwide).

A Michelin study released in 2008 found that only 3 percent of drivers worldwide want run-flat tyres. US share is well below 1 percent. These are used mainly by BMW, GM, Toyota.

Honda dropped the tyres after some owners in the Honda suit said the tyres wore out at around 15,000 miles. The owners alleged unreasonable tread wear, high replacement costs and difficulties finding a repair shop.
vasudeva is offline   Reply With Quote
Old 27th August 2009, 13:40   #2
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,763
Thanked: 89,531 Times
Default

I've never been a fan of runflats. And if & when I ever buy a BMW in India, the tyres will be changed to regular straight at the showroom itself.

Firstly, BMWs are anyways tuned for handling over comfort. And the runflats, with their stiffer compound & poorer sidewall flex, firm the ride up even more. I was shocked when I drove the new 7 series for the first time. The difference in comfort - to the S Class - was glaringly obvious.

Second, even if a car is equipped with runflats, why the heck won't they provide a spare? If I'm mid-way to Goa (300 kms either way to the nearest BMW dealer) and damage my runflat tyre, what the hell do I do?

Not to mention, the cost of replacement. I remember Sahil posting it cost him 20 - 22K for a new tyre! Even if there is a BMW dealer 50 kms away, and I drive to his shop, the runflat is entirely damaged with that drive. Thus, I have to shell out 20,000 for a new tyre?! I'd much rather switch to a spare which doesn't take more than 15 minutes.

Runflats are more a stop-gap to something better. No thanks for the moment, regular tyres have served me just fine. Good move in dropping 'em, Honda!
GTO is offline   (1) Thanks Reply With Quote
Old 27th August 2009, 14:00   #3
Senior - BHPian
 
Join Date: Mar 2007
Location: Delhi
Posts: 2,175
Thanked: 128 Times
Default

After the Honda fiasco, Michelin is now offering a 3yr/36000 mile warranty on run flats for owners of the affected models. Also offered is a $300 rebate on a new Odyssey or Acura RL or $110 for the purchase of Honda-approved Pax spare-tire kits.

However, with tubeless, the benefits of run flats (no flats) now appear to be less. Plus at least in the US, depending on its size and the vehicle, a replacement run-flat costs about $200 to more than $500, compared with about $100 for a typical high-quality tyre. In addition, Dave Cowger, GM's engineering group manager for tyre and wheel systems, said run flats are 20 to 40 percent heavier than a conventional tyre because of a thicker sidewall. They also have higher rolling resistance, so they reduce fuel economy by about 1 to 2 percent. Based on their higher penetration and better economies, the tyre industry may invest in reducing these disadvantages. That now seems unlikely considering that Honda is deserting run flats.

I am of the opinion that good tubeless have basically removed the need for run flats at least in Indian speed conditions. I have a tubeless Bridgestone which has had only 1 instance of puncture in close to 42K/30 mths of driving. That too, I am not sure (the dealer driver had picked up my car for service and he reported the flat).

Another thing to note is that this setback for run flats is not good news for tyre makers such as Michelin, Goodyear, Bridgestone, which were hoping to promote run-flats to OE to get better margins and move away from the highly competitive tubeless market.

Last edited by Rehaan : 27th August 2009 at 18:50. Reason: Posts merged. Please use the EDIT button to add to an existing post within 20 minutes instead of posting another consecutive post.
vasudeva is offline   Reply With Quote
Old 28th August 2009, 12:17   #4
Senior - BHPian
 
aaggoswami's Avatar
 
Join Date: May 2007
Location: Vadodara
Posts: 4,675
Thanked: 1,427 Times
Default

1) I saw in NatGeo program that there is another solid layer after the tyre surface in run flats. This layer is connected to the rim with spokes ( ofcourse very small ) and the surface is quite stiff. Dont know if this is true for all run flats or not.
Basically there is not a huge logic behind run flats being available in cars. They are good for emergency situations, but I am sure in case of a puncture in run flats, the ride quality will be reduced even further.
And if all the 60-80 kms are used after the puncture, the life of run flat tyre is already reduced. This means a new tyre will be required = business for many.

2) BMW designed the 5 ( or 3 ? ) series such that there is no space for spare wheel. I mean in the bodyshell there is space for spare wheel and this is where the spare wheel is located in all cars, under boot floor. But for the 5-series there is no such space. There was an issue reported in TOI a long time back that Indian norms require the spare, and BMW was not happy about it.

I dont exactly remember if it was 3 series or 5 series, but BMW was very unhappy.

Run flats are not required by owners that is observed internationally too, but in India they will not listen to customer.

Image ( the source of both the images is Google ).
Attached Images
  

Last edited by aaggoswami : 28th August 2009 at 12:28.
aaggoswami is offline   (1) Thanks Reply With Quote
Old 10th October 2009, 16:40   #5
Newbie
 
Join Date: Sep 2009
Location: MUMBAI
Posts: 4
Thanked: 0 Times
Default

Quote:
Originally Posted by GTO View Post
I've never been a fan of runflats. And if & when I ever buy a BMW in India, the tyres will be changed to regular straight at the showroom itself.
|
|
|
Runflats are more a stop-gap to something better. No thanks for the moment, regular tyres have served me just fine. Good move in dropping 'em, Honda!

hey you got your BMW secure so why worry

Last edited by Eddy : 10th October 2009 at 17:26. Reason: Please do not quote the entire post for a one liner reply.
gs2660 is offline   Reply With Quote
Old 10th October 2009, 18:24   #6
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,763
Thanked: 89,531 Times
Default

Quote:
hey you got your BMW secure so why worry
If my runflat goes bad on the way to Goa, 300 kms each way from the nearest BMW service station, BMW secure ain't going to help me. And if they do, it'll take them 5 hours to get to where I am. In a country like the States, where you have access to runflat shops pretty much every 30 miles, sure its a different story. However, in India, I am frequently touring places that are more than 200 kms away from any BMW showroom.

What then?
GTO is offline   Reply With Quote
Old 27th September 2011, 22:39   #7
Distinguished - BHPian
 
Join Date: Mar 2011
Location: Back to Chndgrh
Posts: 2,203
Thanked: 2,957 Times
Default Re: Run Flats could go Flat

Well this happened Yesterday - I was driving to Hissar from Chandigarh and about 100 Km short of Hissar , front left tire went over a pothole & got an inch long cut , this was first time on my 530D which has much larger profile 55 ( 225X 55X 17 ) than my x6 on which its kind of regular affair .

Since my appointment was urgent , I continued at lower speeds <80 Km as advised by BMW , could do about 50-60 km without an fuss but after that I could go no further , had to park the car at friendly Toyota Dealership . Now getting tire of this kind about 200 Km away from BMW dealership is really a pain though BMW dealership offered to send Flat Bed but at costs since this wont be covered under Insurance . I was reluctant to use Flatbed not just for money but kind of wastage - towing the car for what a Tire burst

Eventually a tire with almost similar specs was found in Hissar & Toyota guys went out off the way to replace the Tire at there workshop without even charging a paisa - Thanks to Mallik Toyota

Now if the Tires can't last 200-300 Km after getting damaged - How can BMW India assure customers on this technology ?
Attached Thumbnails
Run Flats could go Flat-img2011092600086.jpg  

Run Flats could go Flat-img2011092600087.jpg  

Run Flats could go Flat-img2011092600088.jpg  

Turbanator is offline   (5) Thanks Reply With Quote
Old 28th September 2011, 09:02   #8
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,629
Thanked: 10,876 Times
Default Re: Run Flats could go Flat

That's an eye-opener. If 50-60 km can do that to an RFT, and BMW service wants to charge the owner for sending a flatbed to fetch the car (instead of just sending a tyre across to replace), it's no surprise that one doesn't see too many BMWs on the Indian highways.
SS-Traveller is offline   Reply With Quote
Old 28th September 2011, 19:08   #9
Senior - BHPian
 
Join Date: Aug 2010
Location: Delhi
Posts: 2,133
Thanked: 1,006 Times
Default Re: Run Flats could go Flat

The concept of run flats is excellent, but let down by lack of repair shops and costs of replacement.

According to US users, run flats even there are a pain, though BMW takes the onus of repairs there, unlike in India.

Run flats are excellent for small punctures, even life saving in case of a tyre burst or when you are chased by miscreants on a lonely highway, as you can continue driving on the carcass, but at the cost of ruining not only the tyre, but at times the rim. So it is a safety feature, but in a cost conscious country like India the idea does not gell with most of us.
Aroy is offline   Reply With Quote
Old 28th September 2011, 21:38   #10
BHPian
 
Join Date: Feb 2008
Location: New Delhi
Posts: 313
Thanked: 121 Times
Default Re: Run Flats could go Flat

Ouch! That looks Ugly and Unfortunate. I don't see a fantastic solution in Runflats if the Tyre itself has got a cut. Punctures et al are OK and in fact peace of mind. Cuts, no peace.

How about space saver wheels? You intending to pick one?

I hope, rest of the car i.e. suspension and rim etc are all right and it is just the tyre that needs replacement.
BeamerBoy is offline   Reply With Quote
Old 28th September 2011, 23:22   #11
Distinguished - BHPian
 
Join Date: Mar 2011
Location: Back to Chndgrh
Posts: 2,203
Thanked: 2,957 Times
Default Re: Run Flats could go Flat

Quote:
(instead of just sending a tyre across to replace)
They offered a loaner to my person at Chandigarh though .

Quote:
rest of the car i.e. suspension and rim etc are all right
How about space saver wheels? You intending to pick one?
ya , fortunately rest everything is very fine , in fact these photos were taken about 1 Km before I found Toyota Dealer , by the time I parked , it had gone even worst - shall post photos soon . I think Toyota guys even did balancing !

I was able to buy a Michelin one with little lower profile and shall use this as spare , I have spare Alloy already .

Yes , this is an eye opener as till date I have driven with flat tires less than few Kms mostly with punctures & was able to use the Tire again . But given the road conditions we have more chances of getting the cuts more so if travelling to rural parts .

Last edited by Turbanator : 28th September 2011 at 23:26.
Turbanator is offline   Reply With Quote
Old 29th September 2011, 10:16   #12
Distinguished - BHPian
 
sgiitk's Avatar
 
Join Date: Dec 2007
Location: Kanpur
Posts: 7,163
Thanked: 3,759 Times
Default Re: Run Flats could go Flat

I will prefer the ease of mind which is only there with a donut in the back. I may however compromise on a space saver spare. But as GTO puts it a proper repair point may be 200km away, then we will be forced to take the services of the roadside pancharwallah.
sgiitk is offline   Reply With Quote
Old 29th September 2011, 10:36   #13
Senior - BHPian
 
Join Date: Aug 2010
Location: Delhi
Posts: 2,133
Thanked: 1,006 Times
Default Re: Run Flats could go Flat

Quote:
Originally Posted by Turbanator View Post
They offered a loaner to my person at Chandigarh though .

Yes , this is an eye opener as till date I have driven with flat tires less than few Kms mostly with punctures & was able to use the Tire again . But given the road conditions we have more chances of getting the cuts more so if travelling to rural parts .
From what I have read on the net, running on a Flat tyre for a couple of km, with the "Run Flats", stresses the side walls which may lead to premature failure in future. It may be that the tyre shown; where the side wall has failed; may be the one you ran with a puncture. With the side wall weakened a strong nudged and it finally gave way.

My personal feeling is that as long as you are traveling in city or on well maintained highways, run flats are excellent, but once you are on our "normal" roads far away from nearest dealer, the run flats are a liability. Add to that the fact that there is no spare tyre, you have a recipe for disaster. It is high time that BMW recognized the limitations of run flat tyres in Indian conditions, and a least offered normal tyres and a spare as a factory option.
Aroy is offline   Reply With Quote
Old 29th September 2011, 10:48   #14
Senior - BHPian
 
Join Date: Apr 2008
Location: Dombivli
Posts: 2,627
Thanked: 1,191 Times
Default Re: Run Flats could go Flat

Quote:
Originally Posted by vasudeva View Post
The owners alleged unreasonable tread wear, high replacement costs and difficulties finding a repair shop.
Quote:
Originally Posted by GTO View Post
In a country like the States, where you have access to runflat shops pretty much every 30 miles, sure its a different story.
Looks like even in the States the owners are unable to find stores to repair their runflats ;-)

I guess the need for runflat tyres would be more for secure transport, such as VIP vehicles or vehicles carrying high value items (ATM vans?), where there's a possibility the tyres may be shot and the vehicle still needs to be able to make a getaway. This is impossible with any other tyres, and the runflats in this case would be an investment in security which pays off (even though the tyres will have to be discarded).

Putting these onto the ordinary passenger cars might actually be questionable.
honeybee is offline   Reply With Quote
Old 29th September 2011, 11:13   #15
BHPian
 
Join Date: Nov 2007
Location: Pune
Posts: 69
Thanked: 15 Times
Default Re: Run Flats could go Flat

A cousin who owns a BMW 5 series was going to Jodhpur from Ahmedabad when one of his front tires got a cut on a pothole. He was in the middle of no where without a spare in a 60 lakh car.

Luckily he was traveling with friends, so he shifted into another car, leaving a driver with the stranded beemer.
He somehow convinced the BMW dealership in Ahmedabad to send a 'spare' tyre to the cars location, at additional cost obviously. From my cousins perspective, it was the most embarrassing and frustrating experience he has faced in 20 years of driving cars.

He now keeps an additional tyre in the trunk even though it reduces the capacity of the trunk by over 40%.

HR
hell_raiser is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dilemma - BMW X5 - No spare wheel & Run-flats ackyash Luxury, Imports & Niche 25 24th July 2012 01:56
Run-Flat tyre dealers in Mumbai? Sahil Tyre & Alloy wheel Section 25 13th July 2010 15:15
BMW X5 - 255/55/18 - From Run Flats to Conventional x5india Tyre & Alloy wheel Section 1 24th October 2009 01:17
Need advice on selling bmw x5 run flat tires (then getting new ones) x5india Tyre & Alloy wheel Section 13 6th June 2008 21:27


All times are GMT +5.5. The time now is 19:11.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks