HighlandPete

I'm in an auto, true, it is a pretty advanced box by comparison to many older ones, but honestly, an auto it is not an issue. As said, 2nd gear starts are the typical auto snow/poor surface programme. Drive gently, use the throttle lightly. No need to copy the folks we see (manual or auto), spinning at 1,000's of revs and getting no where. I will typically use the full auto 'drive' mode in good quality snow, but when there is poor snow/ice conditions, will go over to manual mode and particularly so for engine braking, to benefit from the car retarding from the rear and keeping maximum stability. HighlandPete

I've had to use my car on a steep and S curved drive, 200 metres or so in length. A lead in off the main road, with a start from walking speed. 1 in 5 I'd gress, in the curved section. That tests all the working parameters, both going up and even worse, coming down. Nothing with summer tyres will touch it, if covered with snow, needs winter tyres, or AWD. Plus I've used my car on other snow covered sloping sections with no speed to start with, and no issues with just moving off and doing what was needed. Running normal roads through the Glen, absolute confidence and when out there on my own, with no other traffic, you can drive with total control at reasonable speeds, much faster than you'd dare even think off with the wrong tyres. It is other cars I worry about more, as they are the ones giving you issues. HighlandPete

I run Vredestein Wintrac Xtreme on my BMW 330d, put them back on this week, as the temperatures have dropped. Last winter they did everything thrown at them. I ran a few tests myself, (winter and summer wheel sets), on the same day, on our lane covered with solid ice and thin snow topping. Difference like night and day. Braking was most impressive. Also used it regularly, on thick fresh snow, ice, slush, up hills, forward and reverse up slopes. No issues with braking or car control, oh... and traction grip. I had a car go out of control in front of me on black ice, and I had to brake mid corner, (worst case scenario for a winter tyre test) saved me ditching the car. Although I had a little bit of slip, was able to easily keep the car under control. Came back later to see another car had ditched on the same bend and had ended up in the tress. That could have been me. Only slight negative, deep standing water to the verge edges is common up here, the Vred's tend to aquaplane more easily than my summer tyre set. HighlandPete

There is certainly good reason to accelerate quite briskly, using the engine where it is pulling strongly and working most efficiently, which gives the lowest BSFC, (Brake Specific Fuel Consumption), but we don't often get to see a fuel consumption map for our particular engine, to know exactly the best revs and loading to get best fuel consumption. It's a bit of trial and error, learning to get the economy 'sweet spot'. Also brisk acceleration in an appropriate gear, allows us to block change, (skip a gear or two) when up to cruising speed, which can also help economy. HighlandPete

Strange as it may seem, the Michelin is the best many have used. I know from personal experience an 18" Michelin PS2 ZP, is the best working RFT I've driven on a 3-series car. Much more like a 'normal' tyre. I do wonder if the run-on capacity is the same as the Bridgestone. HighlandPete

Remember reading it when you first posted it Tony, has to be BMW's stance. I'm more thinking on the lines of this sort of comment. http://www.tyresafe.org/news-and-events/de...standard-tyres/ There were others at the time and tyre shops have used those comments to refuse to fit non run-flats on customers cars with OEM run-flat fitment. Yes refused to fit non run-flats, other users have been asked to sign a waiver document. HighlandPete

It seems that most insurance companies have no issue at all. I've had dealings with a couple, including Direct Line, and they certainly want notification, as they do for fitting winter tyres, but appear more interested in the rims you use. In other words, are they OEM, or some 'aftermarket' modification? What many have found, as long as you are using tyres to the BMW recommended load/speed rating, or above, there are no issues. Fitting on the OEM rims is fine, as Tony has commented, even BMW have fitted non run-flats to satisfy customer complaints about RFTs. I discussed it with one dealer and he even checked with a customer, as to what tyres he was using on his 3-series, and his comments on the changes. The garage just reminded me to consider the options for an emergency, like space saver, mobility kit, etc. The industry has published and distributed scare type documents about changing from RFTs, from what I understand. Many are nervous about fitting non run-flats since that exposure. Tony may have seen them, one is published by TyreSafe. HighlandPete

I thought the PAX system had bit the dust, after the class action in the States. Business News From reports on the Class Action HighlandPete

I'll go with stress fatigue, can be high duty cyclic loadings, even without any stress raiser. Could be some age hardening depending on the material. The experience with BMW wheels with RFTs, show rims can crack like that, sometimes several places around the rim, (seen seven cracks on one inner edge) so suggesting loadings are far too high for the expected life cycle. HighlandPete

In many countries run-flats will be mandatory, so BMW are compiling, but seemingly they are not making geometric considerations..... we are. Don't forget BMW suspension is designed for run-flats..... often quoted by BMW. Nah, they can't be wrong. :lmaosmiley: I've seen pictures like above, where the tyre has seperated. Get the warning 'bong' and 5 miles further on, total tyre failure. So looks like the X5 had a very close call before failure. Also seen pics where it looks the same as above, but with a flat and the owner was praising the run-flat as it 'probably saved his life'. Don't think everyone using the run-flat is getting, that without very close inspection, run-flats are contributing to premature tyre failure. HighlandPete

I'm sure localised contamination, corrosion, run-out, are all bagged together as 'warped' to many. A badly mounted disc with resulting run-out, can be forced to 'sort of warp', during braking, to try and run true. So after removing, if measured for run-out it, can actually read as 'warped'. HighlandPete

+1 The indirect system is really a very poor system when we think about it. Many users won't have any idea. I also fear that there will be even less checking of pressures than at present. HighlandPete

If only more folks would ask 'why' when the obvious doesn't fit the problem, then the motoring industry would have a few more friends. Good to hear when success is achieved by a bit of 'out of the box' thinking. WIM 1, Merc Nil. HighlandPete

Are they spy shots of a tyre maker, testing the latest run-flats? A real alternative to the Brickstones.... HighlandPete

So true... Worked in a Triumph/Rover garage at the time and heard it all... "I think I've cooked the engine", "and I bled it properly", "was only a small water leak". HighlandPete

Tony, so refreshing to see and read such a statement. If only more businessmen could see beyond the immediate cash benefits of any decision. I believe you should 'wobble your head' as much as you like. HighlandPete

Ain't it the truth... was down at the dealer a couple of weeks ago and a nearly new 3-series was sat outside the entrance with front wheels turned. The outside shoulders on the front tyres were absolutely hammered. One of the worst I've ever seen on a car, but plenty of tread (6 - 7mm) in the middle. Bet he's the sort of driver who 'loves' the sharp turn in on the big rims. HighlandPete

Martin Your pictures do appear to show more wear on the inside, whether the type of driving, or needing an adjustment, only a check will show. I know from the wear pattern and tread depths across the tyres, I'd personally be running a couple more psi than your original figures, to try and balance out the wear rates. On the bigger issue of getting high mileage out of our current tyre designs and specs, even for motorway use, we do seem to be all over the place with what users get. I'm sure Tony is seeing this all the time, and some unusual wear, even when the geometry is inside manufacturers tolerances. HighlandPete

A personal viewpoint, but I'm sure quite a few will have been caught by excessive, or odd tyre wear, due to the colder than average winter period. Some will be due to tyres running lower working pressures, due to not warming up the same. Are you planning to visit WIM, to have the geometry checked? As you mention the inside wear is different, may be wise before fitting new tyres. Have you any pictures of the wear pattern to post on the thread? HighlandPete

Martin Noise generated from tyres on the latest BMWs is not unusual, some tyres have had many complaints and even Technical Information Bulletins (TSB) on the issues. Not a simple issue or easy solution. As to the rear middle wear, (I'm sure Tony will add his comments), but it is not all about overinflation. Centrifugal growth at high speed and high tractive forces, particularly on high powered RWD cars can cause far more middle wear on rear tyres, than a couple of increased psi. You can still get rear middle wear on high powered RWD cars at low setting pressures. Which brings me to another variable we sometimes miss. When using the lower pressure values, (which makes things worse) we sometimes never achieve the hot working pressures we really ought to be running. Cold/wet weather can accelerate tyre issues, often we do not consider the pressure setting may not be high enough for our use. Easy to be running 3 - 5 psi lower than we think, just because our tyres don't get hot during some conditions of use. We do need to compensate, particularly on low profile tyres, as the wear rate/pattern is far more critical than running 'loads of rubber', from my experience. HighlandPete

At least we have true 'like for like' tyres. Eliminates one issue. You mention the 'saw tooth' on both shoulders, you mean of the same tyre? If so, are the saw tooth forms in the same direction? Meaning the leading edge is towards the front on either shoulder, (hand across them at the top of the wheel). Gives a clue the geometry is not far off ideal settingas, if at all needing adjustment. I still believe a part of this wear is accelerated by running pressures at the low side of BMW's recommended rating. As said before, many users find the tyres need more pressure to work better and also balance the wear patterns. It is hard to wear the middles of front tyres on BMWs, without using excessive pressures. You'd notice the compromised drive chartacteristics, before you ever had too much pressure, if you increase and try at small incremental increases. You mention the weight... it is all relative, light weight materials don't mean the car is light, still a 'weighty' car in real terms. The use of aluminium has really just stopped our cars getting too bloated in weight. I swapped my original Bridgestone tyres 'side to side' to balance the heel and toe wear, which it obviously did, but the tyres were never as quiet afterwards. Stopped them getting worse and higher pressures slowed down the shoulder wear, but still came off at 15k miles with loads of middle tread, but useless as tyres. HighlandPete

Just a thought, are the replacements OEM as in BMW 'star' rated/marked tyres, or the standard Continental offering of the same type and size? That can make a big difference on tyre wear and performance. HighlandPete

What pressures do you run on those front tyres? Checked regularly? Do you make lots of short runs, less than 12 - 15 miles? I hope you haven't been relying on the TPWS* for warning of a low pressure, as it can take a significant drop in one tyre to trigger. The big problem with the indirect ABS wheel sensor based system we have in the UK, if all tyres drop over time we can run on far too low a set of pressures, without any warning. It requires quite a rapid air loss, on the run, to get the warning trigger. Or something like an overnight slow pucture to get the warning 'bong'. * BMW don't normally use the TPMS (Tyre Pressure Monitoring System) reference anymore, as it is not strictly a monitoring system. But use acronyms such as TPWS (Tyre Puncture/Pressure Warning System), latest is, Tyre Defect Indicator (TDI). There's been a false sense of security, which has lead many to feel they don't need to check tyre pressures, they'll be told when to. HighlandPete

Interesting thread... This problem does seem to be very common on BMW suspension setups, even from new. One thing I've noted on three different tyre makes (on one car) that they all have the tendancy to 'heel and toe'. One thing I've kept a close eye on is, inside vs. outside, tendancy to 'heel and toe'. Obviously asymmetric treads will be slightly biased to one side, but directional tyres of symmetrical tread patterns will wear very similar either side of the front tyres. That teaches me the tyre, along with use, is more the culprit, rather than the geometry. I know a lot of BMW users run the low pressures on front tyres, to try and help comfort, and stop some of the steering/tramlining issues, but to me that is a asking for tyre wear issues. Comfort and more control comes with smaller rims and more rubber, not ultra low profiles and compromised pressures. Best performance, even unloaded often requires about +0.2 bar (3 psi), than the low placard recommendation, on front tyres of many BMWs. I'm not at all surprised at the side wind issue and low tyre pressures contributing to it. To me 30 psi on 19" front tyres seems so low anyway, with a 6-pot diesel sitting above them, whether it is a 3 or 5-series. I run 2.4 bar (35 psi) on the front of my E91 330d touring for normal use, and that is on 17" tyres. HighlandPete

As an engineer I sense tyres are getting far too hi-tech. Too much expected from one component in a suspension system. The problem as I see it, as the technology gets even more complex, more compromises can come back and bite the users and manufacturers. Wait until the Bridgestone G3's come into the market, rubber with heat reactions seems a step too far, IMO. Perhaps the reason we are waiting longer than anticipated, from the big PR exercise, before product is ready. HighlandPete