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