Had a scary experience with Runflats

anthony_h · 08-17-2005, 09:37 AM

No, I haven't purchased anything from tirerack.com but I'm seriously looking for an alternative. Paying $2400 for new tires is ridiculous in my opinion. Runflats or not it's a lot to pay for tires with a tread rating of 180.

TireTrends.com? I'm gonna look into that. Thanx! I'm hoping that by the time I need new tires, there will be more runflat tires available so that the price goes down.

xyz123 · 08-18-2005, 01:11 PM

In Europe and most of the USA finding a replacement runflat tire within 300 kilometres of anywhere in the event of a puncture is probably not a much of a problem. Where I live, Canada, the geography is such that there are large, sparsely populated areas where finding a replacement tire locally for a BMW will always be a problem, even if runflats become the new norm. However, rather than moan about runflats, I have a strategy that I am confident will bail me out in the unlikely event of a flat.

Since I happen to do more than 90% of my driving in places where a replacement can be found within 300 kilometres, I am in the camp of those who say that runflats are a good idea and I won’t bother carrying a spare. For the other 10% of my driving, basically one or two fairly long vacation trips per year, I plan to carry a spare tire but not a spare rim. While I expect that tires in the right size will be impossible to find in the places I travel, there are garages everywhere that can change a tire. Since I will have a sport package with different tire sizes front and rear, the spare will be a front tire. For safe handing, it is essential that the fronts be a matched pair (size, tread pattern, rubber compound, and age) but in a pinch, it will be safe to drive with rears of different widths until I get home. I am assuming that a front tire can be mounted on the wider rear rim at least temporarily, hope I'm right.

I am thinking that a spare tire without rim in the trunk will not take up much space; clothing or other soft items in plastic bags could be stuffed into the tire and of course, the centre is available storage space. I will wait until I wear down the original tires to the wear indicators before selecting one of the used fronts as my spare; buying a new tire to use as a spare would be a waste because in all likelihood, it will probably never be needed. I have driven somewhere between 800,000 and 900,000 kilometres in the four BMW 3’s I have owned so far and have had only 3 punctures so I am not paranoid about the chances of getting a flat. Rubber ages, even if not used, and a spare that is more than about 4 years old should not be matched up with a new tire to replace a worn pair but should be okay as an emergency spare. My experience with the old 2002 was different, all 5 tires delaminated and threw their treads within a few thousand miles; that was an obvious design or manufacturing flaw and would be the subject of an irate class action lawsuit these days but in those days, there were only a handful of BMW’s around and the manufacturer, Continental, wouldn’t even replace the tires.

jlr · 08-18-2005, 01:26 PM

I have run flat insurance on my 2 month old 330i. My tire alarm went off a week after I got the car. I though this over engineered
car is giving off a fals alarm. The BMW dealership found a screw in the
tire. I drove off an hour later with a new tire and cost me nothing. The run flat is worth it when in a growing city like Atllanta. All the
pick up trucks building houses drop nails on the road.

My question is..... Do you have to get your new tires from BMW for them to be insured or can you buy them anywhere?

etherbored · 08-18-2005, 01:58 PM

MY question is:
is tire insurance a rider to ones personal auto insurace coverage...
?
-e-

itznin · 08-18-2005, 02:30 PM

After reading this the $350 I spent for my tire protection seems all so worth it.

All I need is one experience for it to pay for itself - or better yet one wheel, and it will really pay for itself!

rjtsc583 · 08-19-2005, 02:48 AM

i got my e90 a month ago but the dealer failed to inform me of the tire insurance, can i still get one eventhough i already took delivery of the car?

xyz123 · 08-19-2005, 05:35 AM

I am guessing that tire insurance only replaces the tire with the flat. Don't forget that tires that are more than a few years old or that have significant wear, or both, should be replaced in pairs, fronts or rears, so that if you get a flat later instead of soon after you get a new car, you may be stuck with paying for one tire even if you have insurance.

ben1364 · 08-19-2005, 08:20 AM

One of the earlier posters to this thread mentioned the hope that BMW would see fit to make run flat tires an option. I share that sentiment. While the concept is good, I don't think run flat tires, at least those currently available, belong on performance cars. They are stiff and give no feedback from the road.

Tierfreund · 08-19-2005, 08:25 AM

Quote:

Originally Posted by ben1364

One of the earlier posters to this thread mentioned the hope that BMW would see fit to make run flat tires an option. I share that sentiment. While the concept is good, I don't think run flat tires, at least those currently available, belong on performance cars. They are stiff and give no feedback from the road.

So are low-profile tires and yet they´re considered beneficial for performance cars. So whaddaya mean?

E90JET · 08-19-2005, 09:17 AM

Anthony_H...

Could you tell me which dealer in Ottawa gave (sold) you a new tire off of another car? I mentioned in another section of this board the trouble that I had (am still having) getting a replacement tire for my 325i. There are apparently no tires available anywhere in Ontario or Quebec, even at tire shops. Supposedly back-ordered for another week or so. The dealership I dealt with never offered to replace with one off another car even though they had lots of them in the lot. I've been driving with a puncture now since the Aug 1 long weekend.

ward · 08-19-2005, 09:26 AM

if "tire insurance" was in your benefit, the dealer wouldn't sell it

The odds are very against something like this happening, and happening close enough to your dealer to do any good

I'm glad to say my dealer didn't try and sell me that policy

ward · 08-19-2005, 09:28 AM

Quote:

Originally Posted by Tierfreund

So are low-profile tires and yet they´re considered beneficial for performance cars. So whaddaya mean?

runflats are much heavier than regular tires, adding to unsprung weight making it harder for the suspension to follow the road.
Tires can be too stiff, a tire has to give a bit to follow the contour of the road and maintain a good contact patch. if the tire gets too stiff it actually works worse, much like the kids who lower their cars 2 inches and drive around on the bump stops thinking they've improved their cars

Tierfreund · 08-19-2005, 09:42 AM

Quote:

Originally Posted by ward

runflats are much heavier than regular tires, adding to unsprung weight making it harder for the suspension to follow the road.
Tires can be too stiff, a tire has to give a bit to follow the contour of the road and maintain a good contact patch. if the tire gets too stiff it actually works worse, much like the kids who lower their cars 2 inches and drive around on the bump stops thinking they've improved their cars

Good explanation that I can agree with. Though stiffer sidewall are not only detremental to handling. To a degree they can sharpen the handling by giving less flexibility in the steering.

I guess as usual, too much of a good thing is a bad thing.

Though my personal experience going from non-RFT on the E46 to RFT on the E90 is that handling and roadholding of the RFT´s are exellent (I´m on the 224mm 17 inch wheel combined with the sports suspension).
My beef with the RFT is the poor damping they provide on smaller irregularities and sharp inpacts. Feels like a tire that is severely overinflated (not a problem of the suspesion which works fine in controlling the bigger bump and handling the body movement)

And it´s true, the heavier weigth is noticable. In that respect the 17in RFT´s feel a lot closer to the heavy staggered 18inch non-RFT´s I had on my E46. I had a 17inch non-staggered non-RFT winter tire setup on the E46 that felt a lot better.

But overall, I´ll take the tradoff of the RFT´s happily. Yes, there´s a price to them, but it´s bearable. And after having to change a left front tire once on a 6 lane Autobahn with no more than 1yard between my back and an incredible succession of 40ton trucks who in turn were beeing overtaken by kamikaze drivers in fast BMW´s, Audi´s and Mercs (the perspective drastically changes when your stranded yourself and no longer part of the pack), I´ll be happy to take the discomfort of the RFT´s and the higher costs for beeing able to drive out of an uncomfortable situation with a flat (or two as I once had...).

xyz123 · 08-19-2005, 12:07 PM

Quote:

Originally Posted by ward

runflats are much heavier than regular tires, adding to unsprung weight making it harder for the suspension to follow the road.
Tires can be too stiff, a tire has to give a bit to follow the contour of the road and maintain a good contact patch. if the tire gets too stiff it actually works worse, much like the kids who lower their cars 2 inches and drive around on the bump stops thinking they've improved their cars

Greetings Ward,

Now this is pure speculation on my part, since I know next to nothing about tires and cars but my observation from watching television is that racing tires, for F1 for example, are much, much stiffer and much, much heavier than tires for an E90. Yet, it seems that an F1 car holds the road almost infinitely better than an E90. My conclusion from these observations is that tires shouldn’t be considered in isolation and this in turn leads me to consider BMW’s stated justification for run flats as being designed in as part of a sub-system including wheels, tires and suspension as being credible, for that apparently is what an F1 car is, a total system. I know that what you say about unsprung weight was definitely true in the old days, and it might still be generally true today for simpler suspensions. But maybe automobile engineering has made a lot of progress since those old days and we shouldn’t perpetuate old thinking. Of course, a racing tire will have different design priorities and criteria than a street tire, with hysteresis being a much more important consideration. My guess is that stiffness reduces the squirm and heat buildup that kills racing tires but I would also think that, if its effect on comfort can be tuned out by the suspension, stiffness would be a good thing for road tires as well. I repeat, this is pure speculation on my part based on zero expert knowledge.

ward · 08-19-2005, 12:18 PM

I think we're all sort of agreeing with each other,

extra stiffness helps, but if you get too stiff with the tire it's going to cause loss of performance. I think like Tier said, too much of a good thing

I've been out of school too long to remember what hysteresis is.

BMW has almost certainly used the effective spring rate of the tire itself in the suspension calibration, so when softer non run flat tires are fitted the car should be in effect more softly sprung, (not necessarily a good thing)

F32Fleet · 08-19-2005, 03:36 PM

Quote:

Originally Posted by jlr

I have run flat insurance on my 2 month old 330i. My tire alarm went off a week after I got the car. I though this over engineered
car is giving off a fals alarm. The BMW dealership found a screw in the
tire. I drove off an hour later with a new tire and cost me nothing. The run flat is worth it when in a growing city like Atllanta. All the
pick up trucks building houses drop nails on the road.

My question is..... Do you have to get your new tires from BMW for them to be insured or can you buy them anywhere?

Who was your dealer and did they give u a fair price on your car?

xyz123 · 08-19-2005, 05:35 PM

Quote:

Originally Posted by KenB

Formula 1 Tires are not going to be heavier then E90 tires, I did a bit of searching and could not find a definitive answer on F1 Tire weight,

I'll take your word for it because I don't know, but how can you categorically state that F1 tires are not going to be heavier than E90 tires if as you say, you don't even know the weights? I made assumptions based on their appearance on television as I admitted in my disclaimer, so obviously my comments are subject to error but both the tires and rims sure look a lot bigger in both diameter and width. I also assumed that they are stiffer because stiff sidewalls, besides reducing heating due to flexing (hysteresis) ought to better keep a contact patch on the road, another assumption of mine that is subject to error. Obviously, I will happily stand corrected on both if good information is presented that proves them wrong. I have already admitted my ignorance about these matters in the previous post so be kind when you give your proof.

Quote:

Originally Posted by KenB

We really can’t compare F1 anything to Street anything.

My point in mentioning F1, that I evidently did not present convincingly and so was missed, is that tire and suspension design are integral aspects of system design and that heavy and stiff tires can and apparently do work well in a properly designed system, I used the pinnacle of automotive design as an example. Saying that lower unsprung weight is inherently better in all systems is questionable to my feeble mind. I do agree that in the old days of simple suspensions, lower unsprung weight was logically advantageous but that was then and this is now. Progress marches on and I would think that includes automotive suspension design in the E90 implementation. By the way, historically things developed for racing have eventually made their way to road cars, so I am not so sure about "We really can’t compare F1 anything to Street anything."

Thanks for your comments, I learned at least one new thing, that racing tires have thinner treads than street tires.

Tierfreund · 08-20-2005, 01:23 AM

Formula 1 tires are the way they are mostly because of regulations. Wheel diameter is limited to 13inches in formula 1 and the teams have to work from there.
On other classes, like touring cars, with no such limitations wheels usually are as big in diameter as possible (not least to get the biggest possible brakes in) and tires are low profile and wide. They´re wide beause a wider tire has more surface to spreed the heat buildup into so the compound can be softer.
Yet raceing wheels (F1 or other) are true pieces of engineering art in beeing as light as possible for the very nasty loads they have to handle. In rally cars, there even were (and still are) magnesium wheels despite the dangerousness of that material.
Formula 1 cars are so quick because of power, low center of gravity and aerodynamic downforce. They would be a lot quicker if tire and wheel design were unregulated.

But despite all that, you are absolutely right in pointing out that a cars suspension and wheels are a complex system that can be made to work within a wide range of parameters. As F1 shows, even with some disadvantages (F1 regulations, RFT´s stiffer sidewalls and higher weight) the whole system can still be optimized to work quite well. In that respect the E90 which was designed for RFT´s from the start is better of than other cars where RFT only are optional. The E90 chassis is definetly tuned for RFT´s and therefore compensates for some of the disadvantages of RFT´s. The result is therefore better than i.e. the E60 where RFT´s are an afterthought.

I put my trust in the future of RFT´s. As so often in automobile development I believe we´re just at the beginning of a good development. Remember how car´s lost a lot of engine performance when catalytic converters were frist introduced. And look at the power war we´re in now. Or how crash safety laws mad ethe rubber duck out of the formerly handsome MG B. Look at how nice little roadsters manage to look now despite the same laws still being in place.

My guess is in twenty years RFT´s will be the norm and we´ll be making fun at cars still without. Just like gearboxes without synchromesh, manual chokes, carburators etc.

That´s why I fully understand that BMW does not offer a non RFT tire as an option. They´d also have to offer a spare and can´t because they allready took advantage of the RFT concept and left out the spare tire mold...

xyz123 · 08-20-2005, 07:23 AM

Tierfreund, thanks for your comments, very enlightening as always. I guess I was wondering if the mantra of lower unsprung weight is a generalization. I might be convinced that it is not if someone with a real name does tests on an E90 with standard and lighter wheels/rims and publishes in a recognized journal or even a magazine.

I think generalizations are fairly common; another one might be that lighter curb weight is better for handling. I haven’t checked the specifications for weights, so someone will no doubt correct me if I am wrong, but it seems to me that BMW 3’s have gotten heavier and heavier with each new model but the handling has actually gotten better and better.

BellasBmw · 08-21-2005, 11:59 AM

I know that w/ the sport pkg and run flats, you must replace the tires sooner.. does anyone know what the apprx mileage or time to change tires?

NaTuReB0Y · 08-21-2005, 03:04 PM

Quote:

Originally Posted by BellasBmw

I know that w/ the sport pkg and run flats, you must replace the tires sooner.. does anyone know what the apprx mileage or time to change tires?

When the time come....you will know....
LOOK at your tire treads.....hahahahaha!

Seriously....depends on how you drive = treadwear

CC 330i · 08-21-2005, 11:52 PM

Yes, this situation shows the benefits of run flats. I would still carry a tire repair kit (like Slime "Smart Spair"), however. That way if you get a small puncture, you can continue to your destination with pressure still in the tire and could likely get the tire repaired without having to buy a new one.

In the event of a sidewall puncture, of course, you will have to replace the tire, but at least you can continue on to your destination or a safe place (like a hotel or home) until the tire can be replaced. If it were a conventional tire, you may have had a spare, if you knew how to put it on (and some people don't, and woefully too many BMW owners

) you might be hit by traffic putting on the spare, or could be assaulted by someone or robbed.

Blowouts are by far the least common tire failure event, and most blowouts are caused by owners running severely deflated (or in some cases overinflated) tires. With the E90 sensor to detect low pressure, none of us should ever have to worry about continuing to run a tire that is severely low on pressure. We should all check our tire pressures manually often also, as this will ensure the best tire life, fuel economy, and performance.

08-17-2005, 09:37 AM	#23
anthony_h Second Lieutenant 40 Rep 215 Posts Drives: E90 325i 6spd Join Date: Mar 2005 Location: Toronto On iTrader: (1)	No, I haven't purchased anything from tirerack.com but I'm seriously looking for an alternative. Paying $2400 for new tires is ridiculous in my opinion. Runflats or not it's a lot to pay for tires with a tread rating of 180. TireTrends.com? I'm gonna look into that. Thanx! I'm hoping that by the time I need new tires, there will be more runflat tires available so that the price goes down.
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08-18-2005, 01:11 PM	#24
xyz123 Private First Class 9 Rep 141 Posts Drives: 2013 E82 Msport, manual Join Date: Jul 2005 Location: Toronto iTrader: (0)	In Europe and most of the USA finding a replacement runflat tire within 300 kilometres of anywhere in the event of a puncture is probably not a much of a problem. Where I live, Canada, the geography is such that there are large, sparsely populated areas where finding a replacement tire locally for a BMW will always be a problem, even if runflats become the new norm. However, rather than moan about runflats, I have a strategy that I am confident will bail me out in the unlikely event of a flat. Since I happen to do more than 90% of my driving in places where a replacement can be found within 300 kilometres, I am in the camp of those who say that runflats are a good idea and I won’t bother carrying a spare. For the other 10% of my driving, basically one or two fairly long vacation trips per year, I plan to carry a spare tire but not a spare rim. While I expect that tires in the right size will be impossible to find in the places I travel, there are garages everywhere that can change a tire. Since I will have a sport package with different tire sizes front and rear, the spare will be a front tire. For safe handing, it is essential that the fronts be a matched pair (size, tread pattern, rubber compound, and age) but in a pinch, it will be safe to drive with rears of different widths until I get home. I am assuming that a front tire can be mounted on the wider rear rim at least temporarily, hope I'm right. I am thinking that a spare tire without rim in the trunk will not take up much space; clothing or other soft items in plastic bags could be stuffed into the tire and of course, the centre is available storage space. I will wait until I wear down the original tires to the wear indicators before selecting one of the used fronts as my spare; buying a new tire to use as a spare would be a waste because in all likelihood, it will probably never be needed. I have driven somewhere between 800,000 and 900,000 kilometres in the four BMW 3’s I have owned so far and have had only 3 punctures so I am not paranoid about the chances of getting a flat. Rubber ages, even if not used, and a spare that is more than about 4 years old should not be matched up with a new tire to replace a worn pair but should be okay as an emergency spare. My experience with the old 2002 was different, all 5 tires delaminated and threw their treads within a few thousand miles; that was an obvious design or manufacturing flaw and would be the subject of an irate class action lawsuit these days but in those days, there were only a handful of BMW’s around and the manufacturer, Continental, wouldn’t even replace the tires. Last edited by xyz123; 08-18-2005 at 01:40 PM..
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08-18-2005, 01:26 PM	#25
jlr Enlisted Member 1 Rep 35 Posts Drives: 2006 33i Join Date: Aug 2005 Location: Atlanta iTrader: (0)	Run flat insurance from BMW I have run flat insurance on my 2 month old 330i. My tire alarm went off a week after I got the car. I though this over engineered car is giving off a fals alarm. The BMW dealership found a screw in the tire. I drove off an hour later with a new tire and cost me nothing. The run flat is worth it when in a growing city like Atllanta. All the pick up trucks building houses drop nails on the road. My question is..... Do you have to get your new tires from BMW for them to be insured or can you buy them anywhere?
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08-18-2005, 01:58 PM	#26
etherbored klactoveesedstene 2 Rep 98 Posts Drives: das gut Join Date: Aug 2005 Location: here iTrader: (0)	MY question is: is tire insurance a rider to ones personal auto insurace coverage... ? -e-
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08-18-2005, 02:30 PM	#27
itznin Captain 26 Rep 679 Posts Drives: 2013 F30 Join Date: Jun 2005 Location: North NJ iTrader: (2)	After reading this the $350 I spent for my tire protection seems all so worth it. All I need is one experience for it to pay for itself - or better yet one wheel, and it will really pay for itself!
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08-19-2005, 02:48 AM	#28
rjtsc583 Enlisted Member 2 Rep 45 Posts Drives: 11' e82 135i, 06' e350 Join Date: Aug 2005 Location: San Diego iTrader: (1)	i got my e90 a month ago but the dealer failed to inform me of the tire insurance, can i still get one eventhough i already took delivery of the car?
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08-19-2005, 05:35 AM	#29
xyz123 Private First Class 9 Rep 141 Posts Drives: 2013 E82 Msport, manual Join Date: Jul 2005 Location: Toronto iTrader: (0)	I am guessing that tire insurance only replaces the tire with the flat. Don't forget that tires that are more than a few years old or that have significant wear, or both, should be replaced in pairs, fronts or rears, so that if you get a flat later instead of soon after you get a new car, you may be stuck with paying for one tire even if you have insurance.
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08-19-2005, 08:20 AM	#30
ben1364 Captain 14 Rep 940 Posts Drives: E90 330iA Join Date: Aug 2005 Location: Georgetown, TX iTrader: (0)	One of the earlier posters to this thread mentioned the hope that BMW would see fit to make run flat tires an option. I share that sentiment. While the concept is good, I don't think run flat tires, at least those currently available, belong on performance cars. They are stiff and give no feedback from the road.
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08-19-2005, 09:17 AM	#32
E90JET Registered 0 Rep 4 Posts Drives: E90 Jet Black Join Date: Aug 2005 Location: Ottawa, Canada iTrader: (0)	Anthony_H... Could you tell me which dealer in Ottawa gave (sold) you a new tire off of another car? I mentioned in another section of this board the trouble that I had (am still having) getting a replacement tire for my 325i. There are apparently no tires available anywhere in Ontario or Quebec, even at tire shops. Supposedly back-ordered for another week or so. The dealership I dealt with never offered to replace with one off another car even though they had lots of them in the lot. I've been driving with a puncture now since the Aug 1 long weekend.
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08-19-2005, 09:26 AM	#33
ward Major General 155 Rep 6,158 Posts Drives: F Join Date: May 2005 Location: T iTrader: (0)	if "tire insurance" was in your benefit, the dealer wouldn't sell it The odds are very against something like this happening, and happening close enough to your dealer to do any good I'm glad to say my dealer didn't try and sell me that policy
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08-19-2005, 12:18 PM	#37
ward Major General 155 Rep 6,158 Posts Drives: F Join Date: May 2005 Location: T iTrader: (0)	I think we're all sort of agreeing with each other, extra stiffness helps, but if you get too stiff with the tire it's going to cause loss of performance. I think like Tier said, too much of a good thing I've been out of school too long to remember what hysteresis is. BMW has almost certainly used the effective spring rate of the tire itself in the suspension calibration, so when softer non run flat tires are fitted the car should be in effect more softly sprung, (not necessarily a good thing)
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08-20-2005, 01:23 AM	#40
Tierfreund Major 21 Rep 1,002 Posts Drives: E90 330i Join Date: Apr 2005 Location: Germany iTrader: (0)	Formula 1 tires are the way they are mostly because of regulations. Wheel diameter is limited to 13inches in formula 1 and the teams have to work from there. On other classes, like touring cars, with no such limitations wheels usually are as big in diameter as possible (not least to get the biggest possible brakes in) and tires are low profile and wide. They´re wide beause a wider tire has more surface to spreed the heat buildup into so the compound can be softer. Yet raceing wheels (F1 or other) are true pieces of engineering art in beeing as light as possible for the very nasty loads they have to handle. In rally cars, there even were (and still are) magnesium wheels despite the dangerousness of that material. Formula 1 cars are so quick because of power, low center of gravity and aerodynamic downforce. They would be a lot quicker if tire and wheel design were unregulated. But despite all that, you are absolutely right in pointing out that a cars suspension and wheels are a complex system that can be made to work within a wide range of parameters. As F1 shows, even with some disadvantages (F1 regulations, RFT´s stiffer sidewalls and higher weight) the whole system can still be optimized to work quite well. In that respect the E90 which was designed for RFT´s from the start is better of than other cars where RFT only are optional. The E90 chassis is definetly tuned for RFT´s and therefore compensates for some of the disadvantages of RFT´s. The result is therefore better than i.e. the E60 where RFT´s are an afterthought. I put my trust in the future of RFT´s. As so often in automobile development I believe we´re just at the beginning of a good development. Remember how car´s lost a lot of engine performance when catalytic converters were frist introduced. And look at the power war we´re in now. Or how crash safety laws mad ethe rubber duck out of the formerly handsome MG B. Look at how nice little roadsters manage to look now despite the same laws still being in place. My guess is in twenty years RFT´s will be the norm and we´ll be making fun at cars still without. Just like gearboxes without synchromesh, manual chokes, carburators etc. That´s why I fully understand that BMW does not offer a non RFT tire as an option. They´d also have to offer a spare and can´t because they allready took advantage of the RFT concept and left out the spare tire mold... __________________ No, not THAT kind of tierfreund!
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08-20-2005, 07:23 AM	#41
xyz123 Private First Class 9 Rep 141 Posts Drives: 2013 E82 Msport, manual Join Date: Jul 2005 Location: Toronto iTrader: (0)	Tierfreund, thanks for your comments, very enlightening as always. I guess I was wondering if the mantra of lower unsprung weight is a generalization. I might be convinced that it is not if someone with a real name does tests on an E90 with standard and lighter wheels/rims and publishes in a recognized journal or even a magazine. I think generalizations are fairly common; another one might be that lighter curb weight is better for handling. I haven’t checked the specifications for weights, so someone will no doubt correct me if I am wrong, but it seems to me that BMW 3’s have gotten heavier and heavier with each new model but the handling has actually gotten better and better.
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08-21-2005, 11:59 AM	#42
BellasBmw If love is the answer,please rephrase the question 315 Rep 1,731 Posts Drives: Tit Silver 325i Join Date: Jul 2005 Location: San Diego, Ca iTrader: (1) Garage List 2006 325i [0.00]	I know that w/ the sport pkg and run flats, you must replace the tires sooner.. does anyone know what the apprx mileage or time to change tires? __________________ ~~BellasBmw~~ Proud mama to 325i/TiAg/Black lette/Pwr seats/Sirius/Sport/Walnut/Step/Xenons/Chrome exhaust/20% tint
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08-21-2005, 11:52 PM	#44
CC 330i Captain 44 Rep 722 Posts Drives: 330i SG/Blk/Alum Join Date: May 2005 Location: Orange County, CA iTrader: (0)	Yes, this situation shows the benefits of run flats. I would still carry a tire repair kit (like Slime "Smart Spair"), however. That way if you get a small puncture, you can continue to your destination with pressure still in the tire and could likely get the tire repaired without having to buy a new one. In the event of a sidewall puncture, of course, you will have to replace the tire, but at least you can continue on to your destination or a safe place (like a hotel or home) until the tire can be replaced. If it were a conventional tire, you may have had a spare, if you knew how to put it on (and some people don't, and woefully too many BMW owners ) you might be hit by traffic putting on the spare, or could be assaulted by someone or robbed. Blowouts are by far the least common tire failure event, and most blowouts are caused by owners running severely deflated (or in some cases overinflated) tires. With the E90 sensor to detect low pressure, none of us should ever have to worry about continuing to run a tire that is severely low on pressure. We should all check our tire pressures manually often also, as this will ensure the best tire life, fuel economy, and performance.
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