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Discussion Starter · #1 ·
I have for some years been wanting to replace my 2003 E39 530d Touring by a new G31 530d Touring, but the tyres, and absence of space for even a spacesaver wheel, put me off.

The obligation for all new cars to comply fully with Euro emissions standard 6d from 01/09/2021 revived my interest .

I would have preferred to continue with RWD. Now the 530Dd-spec models (2022MY, but possibly also 2021MY) are all on a version of AWD (all-wheel drive) called "X-Drive". I would settle for that.

These models are now on standard tubeless tyres (225/55 R17 101 Y XL), apparently with directional ("rotational") tread pattern, meaning that two wheels/tyres are solely for the nearside of the car, and two for the offside. I suppose that a jack is now supplied with the car, so it must have emergency jacking points, and it now comes with one of those rarely usable "tyre repair kits" (don't laugh!).

My E39 has, since 2018, has been on (excellent) Michelin cross-climate tyres, which are also directional. To avoid two spare wheels(!!), I have an asymmetric-tread tyre on the spare (usable on either side of the car). I keep this wheel, because of the very different characteristics of the two tread patterns, strictly for emergency use.

The Cross-Climates are not BMW-starred. My brother-in-law had found them excellent as a genuine all-weather tyre which was nearly as good as the best winter tyres on snow,/ice so I went for them - with experiences during the winter of 2010/11 in mind!

There are no fit problems - the bogey always wheeled forward by BMW main dealer service departments. No comments have been made about the tyres at MOT by BMW techs.

I can't carry a full-sized spare in a G31 - except in the load area, where it would occupy a disproportionate amount of space. Anyway, BMW would, so the dealer says, not approve use of even a full-size spare wheel unless it had a tyre with the same tread pattern/direction as the side of the car to which it was fitted. That is claimed to be "because of the type of all-wheel drive fitted to the car" ("X-Drive). I would take that risk IF there were space for a single spare. This would have a same-spec tyre as OEM, but with a non-directional tread, so as to be usable on either side of the car.

If I am to buy a G31 at all, I must have a spare wheel. A space-saver is a lot better than no spare at all! One of these, in a bag, would be tolerable in the load area, being a lot thinner than a 225, and smaller in diameter when its tyre is deflated (which is how it is normally carried in a smallish underfloor compartment . It has to be inflated if needed. That's not a problem. I would probably carry it inflated, and keep the pressure checked).

Audi apparently approve a space-saver spare for those of their Quattro models that use an AWD system very similar to X-Drive, provided the rolling diameter/circumference of the (inflated) spare is within 3% of that of the OEM wheels/tyres.

But BMW would not approve of their G31 530d running with even a compatible-size space saver on one wheel solely in an emergency (and at no more than 50 mph and for no more than 30 miles)

During the car's warranty period, that's a risk I would have to take - unless the X-Drive is so sensitive to mismatches in the rolling resistance of the tyres as to shut the car down. Is that an actual risk?

Apart from a compatible rolling circumference, a suitable space-saver needs the same bolt-hole diameter and same BCD (bolt centre diameter) as the BMW 5-stud (I assume) OEM wheel on a G31 530d. I suppose that it would also need an offset of the wheel centre rim-to-rim from the hub (ET) as close as possible to that of the OEM wheel.

Can anyone point me towards a supplier of space-saver wheels who might be able to supply a suit able one?

If not, I'll have to make my replacement for the E39 a non-BMW. Because of what an excellent car this E39 has been, and remains (but it's in Euro emissions group 3!),that would seem a pity.
 

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Discussion Starter · #3 ·
Why not just go for run flat tyres, according to the BMW website they are available for this model in all sizes. https://www.bmw.co.uk/content/dam/b...f/G31_Reifenliste.pdf.asset.1619623688420.pdf
Why not just go for run flat tyres, according to the BMW website they are available for this model in all sizes. https://www.bmw.co.uk/content/dam/b...f/G31_Reifenliste.pdf.asset.1619623688420.pdf
The run-flats put me off the pre-facelift version of the G31 in 2017 owing to their reputation for hard riding, and no certainty that one could continue driving the car after the TPWS showed a low pressure at one wheel. Whether or not one could continue one's journey (and then only to the nearest tyre fitter, because that journey is limited to 50 miles/50 mph) would depend on how badly damaged the tyre was.

However, if there is a BMW-approved choice between standard tubeless tyres (default) and SSTs (solid sidewall tyres) (possible post-purchase alternative), I'd (reluctantly) go for SSTs, as they offer a better chance of the car remaining driveable after a deflation - unless I could carry a space-saver spare in conjunction with the standard tubeless tyres, and provided that use of this did not invalidate the new-car warranty..

The BMW list of tyres to which you refer me does not include, among ones coded RSC, an R17 225/55 with load factor 101 as well as speed factor Y. So BMW do not approve a runflat now for the version of the G31 that I have in mind. There is a group of R17s coded RSC, but with load factor 97. I wouldn't go for lower than 101 because we tow a heavy caravan (one within the 2 tonnes/90kg limits of both the E39 and the G31), and BMW wouldn't approve a lower load factor for a car which they have calculated needs 101..

I also note that the manufacturers of the tyres listed as RSC in the first group of the list (for 17" wheels) are Goodyear, Michelin, Hankook and Pirelli. .

According to this list:-


Only Bridgestone (not on the BMW list) and Pirelli (on the BMW list) have a runflat tyre coded RSC.

As regards the four brands of SST on the etyres list:-

Goodyear code their versions ROF (run on flat) and EMT (extended mobility provision).

Michelin code is ZP, which is available on Primacy 4, Pilot Sport 3 and latitude Sport 3).

The etyres list does not include Hankook.

It shows RSC (run-flat system component technology) as a designation used only by Bridgestone.

I may find an R17 225/55 101 Y XL among the three Michelin tyre models. If I do, I would have to check with BMW if it is approved (therefore starred) by them, and, if so, it they approve it for the G31. They will probably say "No" (if it is not made in a starred version to the full OEM spec). Then, if I fitted a set, they might well declare grounds for refusing a warranty claim relating to the X-Drive components (and anything to do with the suspension/brakes) during the first three years of the car's life (general warranty period).

I still consider that the standard tyres for the car (ordinary tubeless) in conjunction with a space-saver spare to be the best solution, but do not know how I can find a spare of this type which would be confidently and arguably compatible with the OEM tyres if the matter went to court as the result of something going wrong with the car during the warranty period while the spare was in use (I mean, if BMW had rejected the warranty claim). Hopefully a very unlikely scenario, but not an inconceivable one!
 

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Discussion Starter · #5 ·
You could just join Green Flag and let them take you home or to a tyre shop, even if you only do it for the warranty period.
I already belong to the AA. I want a solution which allows me to drive the car, with the punctured wheel replaced by a space-saver,.to the nearest tyre shop. I don't want to wait for an AA recovery vehicle. Many of the long journeys we make are with our caravan on the back of the car. That would make a rescue-service recovery even slower.

If I can't get a space saver for the BMW G31 the solution is simple, but rather a pity. I just won't buy a G31. There is no other BMW that meets our needs for a genuine all-purpose car. The X5 is too big for our garage (and for us!), and there's now the same problem about the tyres with this series, as well. That's also the case with the new X3. .For us, an SUV, especially a very large one, is not a genuine all-purpose car

I just wish someone would answer my question, instead of offering me alternative garden paths which I have not asked about because I have already explored and rejected them. The fact that non-one has answered suggests increasingly that there is no suitable and BMW-acceptable space-saver for the G31.
 

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Discussion Starter · #6 ·
I already belong to the AA. I want a solution which allows me to drive the car, with the punctured wheel replaced by a space-saver,.to the nearest tyre shop. I don't want to wait for an AA recovery vehicle. Many of the long journeys we make are with our caravan on the back of the car. That would make a rescue-service recovery even slower.

If I can't get a space saver for the BMW G31 the solution is simple, but rather a pity. I just won't buy a G31. There is no other BMW that meets our needs for a genuine all-purpose car. The X5 is too big for our garage (and for us!), and there's now the same problem about the tyres with this series, as well. That's also the case with the new X3. .For us, an SUV, especially a very large one, is not a genuine all-purpose car

I just wish someone would answer my question, instead of offering me alternative garden paths which I have not asked about because I have already explored and rejected them. The fact that non-one has answered suggests increasingly that there is no suitable and BMW-acceptable space-saver for the G31.
FOR ANYONE INTERESTED, AND JOHNNY GRABBLE SPECIFICALLY

Sorry if I seemed dismissive, Johnny. You were right that the list of BMW-approved tyres for the G31, to which you kindly supplied the link, shows a group of runflats for the SE's standard 17" wheels. The ordinary tubeless tyres (not so ordinary, as they are directional) are in the first group (above the runflats)..

These now-standard OEM tubeless directional tyres for the SE have load rating 101 (825 kg), which means that the back axle can be loaded to the maximum permitted weight of 1,455 kg with the load capacity of the rear tyres being within the 90%, as advised by Tyresafe, of the maximum load that they are required to carry..90% of (825 x 2) 1,650 kg is 1,485 kg. No problem there (apart from no space-saver spare being approved to accompany these tyres,, and no space in the car, without significantly restricting load volume, for one).

The second group of tyres (the runflats to which you pointed me) are all load-rated 97, which is only 730 kg and is clearly unsuitable for a rear axle load of 1.455 kg. At 90% of the load rating, two of these tyres on one axle are OK up to only 1,314 kg maximum axle load.

I can find only ONE runflat to the full OEM spec for the current G31 SE. That is a Pirelli "all seasons" tyre. Even on mytyres it is £250, and it's not starred (BMW-approved), so there might be warranty issues with BMW if there was a fault in the all-wheel drive (X-Drive). No other runflat in the correct size etc and load and speed rating seems to exist, which makes it even more unwise to commit to a set of these, after having paid for the standard tyres, which might not fetch much on the usual auction site, and then find, when a replacement tyre or set is needed, that they are no longer available, and that there are still no others.

I took up with BMW the presence of unsuitable tyres on their list. This was not acknowledged (surprise, surprise), but I was told emphatically that there are no wheel options on the SE which allow runflats to be fitted. Only the standard tubeless tyres (255/55 R17 101 Y) are now approved. For runflats with at least a 101 load rating , one has to go for an M Sport variant and pay for optional 20" wheels and 103 load-rating runflats. But we don't want a rock-hard ride (made even harder by runflats, of course), nor the reduced ground clearance of the lowered suspension on this variant That's at least because of the rise angle of the pavement where we live up to our drive. The front spoiler of our relatively high-riding E39 comes uncomfortably close to that when even this car is backing off the drive. A car with less clearance might well scrape its front spoiler, or break it/get stuck.

So I'm afraid we have to remove the G31 from our short list. Pity, when we have had nearly 20 years' excellent service from what I consider to be the best car I have owned since I started owning a car in 1957. So we may decide to stick with our elderly "lady" (who's covered only 77k even now) until we cease to need a car which combines so successfully "grand tourer" and caravan-lugger. The very out-of-date emissions group (Euro 3) of the E39 is possibly the looming problem (access to city centres, etc), and spare parts - OK at present -. they may well dry up.
 
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