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Hi all,

Just like almost everybody else, my 2018 x3 x30I came with runflat tires which
I am not too happy with. In fact, I would like to convert those back to regular
high performance tires after the initial set of runflat tires worn out.

Does BMW sell a spare tire kit, which at least includes the spare tire rim and the
tire tray to facilitate this conversion? Any part number? I seem to recall seeing
this (without photos) in one of the BMW parts site for 3xx bucks.


Thanks !
 

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I wondered the same thing. I would feel more comfortable having a spare---my X3 did not come with one. I will talk with the dealership and let you know what I find out.
 

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My M...not Hers
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Runflats.... other that expensive to replace what are the negatives. I realize not everyone likes them. I***8217;ve had them since 2006 and swear by them. It***8217;s a good feeling knowing I***8217;ll most likely make it home if air is lost. Not trying to start a debate or argument. Just interested in the negative side of Runflats if there are any. Thanks.
 

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Runflats.... other that expensive to replace what are the negatives. I realize not everyone likes them. I've had them since 2006 and swear by them. It's a good feeling knowing I'll most likely make it home if air is lost. Not trying to start a debate or argument. Just interested in the negative side of Runflats if there are any. Thanks.
My F10 535i came with Goodyear LS2's, which have a reputation of being the worst RFT's around. Also, I practice "tire whispering," where I systematically adjust the tire pressures to achieve even tire wear. With the LS2's, that meant maintaining the pressures at about 15% over what the door jamb decal recommended. Here was my tread depth at 30k miles. After adjusting my tire pressures for optimal, even tread wear, the ride was bone-jarring and the performance of the tires was greatly diminished. Even with the drastic over-pressurization, I wasn't able to achieve perfectly even wear across the tires.

The inherent problem with RFT's is that the rigid sidewalls that prevent a tire from collapsing when deflated also prevent the sidewalls from stretching in the circumferential direction. Circumferential stretching of the sidewall is what makes radial-ply tires superior to bias-ply tires.

The cords in tires (nylon, rayon, aramide) resist stretching. Bias-ply tires have cords in multiple directions within the sidewall, preventing the sidewall from stretching in multiple directions. The breakthrough with radial tires was that the cords are only it in the radial direction. This allows the rubber in the sidewalls, in between the cords, to stretch in the circumferential direction (90 degrees from the radial direction). That sidewall stretching allows for the tread of the tires to conform to the flat road surface. This evens out wear on the tread, and improves traction, durability, and fuel economy.

With a bias-ply tire or an RFT (which has radial cords) the sidewalls have a limited ability to stretch in the circumferential direction. This causes the tread area contacting the pavement to buckle inward, concentrating the weight around the edges of the contact patch. That constant buckling and unbuckling as the tire rolls along also causes the edges of the contact patch to squirm against the pavement. The increased weight and squirming causes increased wear, particularly on the inner and outer edge of the tread. The best analogy is a deflated basketball or soccer ball. The deflated ball doesn't get a flat spot. The total surface area of the ball remains constant, so a depression causes a concave dimple instead of a flat spot.

That circumferential stretching of the sidewalls in radial tires is what causes radial tires to bulge out at the bottom, even when properly inflated.

The breakthrough in RFT's will come when somebody develops a sidewall which will easily stretch in the circumferential direction, but will not collapse in the radial direction.

I refused to buy (or lease) another BMW without a spare tire and a hole under the trunk or cargo compartment floor to put it in. We passed on getting a E84 X1, a F25 X3, or an F15 X5 40e for these reasons. I had to add "or lease" because I wouldn't own a X5 40e (hybrid). But, BMW was offering crazy lease deals on them.

The G01 30i offers not only a spare tire (option code 300, not to be confused with color code 300 (Alpine White III)) for a mere $150, but it also offers non-RFT, 19" all-season tires as a no cost option (option code 25X). With the non-RFT's, BMW throws in the spare for free!

In contrast to the LS2's, the non-RFT Bridgestone Dueler Sport A/S's on Frau Putzer's X3 are wearing evenly with only about the pressure only at about 5% over what is recommended on the door jamb decal. Based on the treadwear at 8k miles, the OE tires should last to around 55k miles.

Replacing the LS2's on my 535i with non-RFT Michelin Pilot Super Sports (PSS's) absolutely transformed the car. Leaving the dealership, driving over the less than one-inch drop between the driveway and the gutter of the street, the ride was so much better that I stopped and checked the tire pressures before my 95 mile drive home.
 

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My M...not Hers
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My F10 535i came with Goodyear LS2's, which have a reputation of being the worst RFT's around.
Thanks for the detailed review. However is it fair to flame runflats because Goodyears are substandard. I think Goodyears are not so Good to begin with....being RF or Non RF. I'm just an average guy that cannot fine tune the difference. The M40i with RF's and a spare are great insurance. Speaking for myself I could not tell the difference if I did an A B driving test. Are RF's problematic safety wise? Why are they OEM...must be something to that.

Would like to hear from other RF owners...like em, hate em, could not care less.

I had a Chevy SSR with no spare and a can of Slime with a compressor. The going line from GM...the vehicle gets better gas mileage(less weight). That is the biggest line of Bull Soup I ever heard.
 

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Thanks for the detailed review. However is it fair to flame runflats because Goodyears are substandard. I think Goodyears are not so Good to begin with....being RF or Non RF. I'm just an average guy that cannot fine tune the difference. The M40i with RF's and a spare are great insurance. Speaking for myself I could not tell the difference if I did an A B driving test. Are RF's problematic safety wise? Why are they OEM...must be something to that.

Would like to hear from other RF owners...like em, hate em, could not care less.

I had a Chevy SSR with no spare and a can of Slime with a compressor. The going line from GM...the vehicle gets better gas mileage(less weight). That is the biggest line of Bull Soup I ever heard.
You only notice the rougher ride when you hit a bump.

I qualified my previous post by saying I had LS2's (probably the worst tire ever put on a BMW at the factory), and that I practiced "tire whispering" to get even wear. If you're willing to let RFT's wear unevenly (more on the inner and outer edges), and therefore quickly, the ride difference would be less.

I had a X3 30i loaner with Bridgestone RFT's and I couldn't tell the difference. But, I didn't hit any significant bumps. Also, since I'm not the one who will be buying new tires for that loaner X3 someday, I didn't check the tire pressures or tread wear patterns.

The non-RFT Michelin PSS's now on my 535i wear evenly at just about the door jamb decal pressures. The decal says 35 PSI in the front, and 39 PSI in the back. I'm running the PSS's at 38 PSI in the front and 40 PSI in the back. I have found over my decades of tire whispering that Goodyear and Continental tires need more pressure to wear evenly than Michelin's or Bridgestone's.

There's a reason, actually multiple reasons, that "real" M cars (M2/3/4/5) and non-M cars with the Track Handling Package (THP) come with non-RFT's.

M cars (and maybe non-M's with THP) have one of those compressors with an integrated slim cartridge. They call it the "BMW Mobility System." I called mine the "BMW (Im)Mobility System." I carried a spare in my E46 M3.

There's a weight penalty of three or four pounds per tire with RFT's. One of the weight penalty mitigation methods BMW used when bringing back spares is to mount them on cast aluminum rims instead of the stamped steel ones. RFT's also have increased rolling resistant, which results in about a one percent increase in fuel consumption.

The current 2, 3, 5, 7 (Alpina B7), and 8 Series offer non-RFT's as options, as do the X1, X2, X3, X4, X5, X7, and Z4. All these platforms except the 2 Series also offer spare tires as options. The current 4 Series is still built on the outgoing F3X platform, which didn't have a spare tire compartment. The current X6 is also built on the outgoing F16 platform. Like the previous F15 X5, it does not offer non-RFT's as an option, but it does offer a spare tire as an option.

The G01 has only been out a little over a year. Few if any G01 owners have bought new tires as of now. If you go over to any of the older platforms' boards, there's a consensus among those who have switched to non-RFT's that doing so greatly improved the ride and performance of their cars.

I keep cars to about 100k miles. I'll get about 55k miles out of the non-RFT's on our X3. That will allow me avoid replacing tires a second time, saving me about $1000. I couldn't have got 55k miles out of my LS2's. I ditched them at 31k because I couldn't stand the ride anymore. In 20/20 hindsight, I wish I'd ditched them at 31 miles.
 

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My M...not Hers
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Hi Auto...other than you do not like them there is nothing wrong with them safety wise correct?
I had a Nissan Cube (yes a Toaster). Tires were replaced at 8000. Worst tread every. Macan tires got replaced at 17,000. Horrible wear and noisy. Not RF's. Regardless of tread wear I replace at just before 50% wear. Currently in Florida...hot roads are a tire killer. I'm a big fan of run flats for now. Would put them on a bicycle if available.
 

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RFT's could potentially save your life if you have a rapid deflation in a place where it's not safe to change a tire. I've driven about one million miles in my life. I'm old and I used to drive a lot for my jobs. But, I've only had one rapid deflation, and it was caused by a defective rubber valve stem, the type no longer used on BMW's. It also happened in a residential area were it was safe to change the tire. I've had literally dozens of punctures over the years. But, none of them resulted in a rapid deflation. I weigh the risks of non-RFT's (having a rapid deflation in an unsafe area) against the benefits (tires that ride better, perform better, last longer, and are cheaper).

I normally don't drive on crowded, walled, interstates in the north east. Driving up to New England a lot when I was working, I'd often say "I'd hate to have a flat tire here." One of the ways I mitigate my risk was to check my tire pressure before and after a day on the road, so I wouldn't start on for a day on the interstate with a nail in my tire. Were I drive now usually has room to get away from traffic before changing a tire.

The cheapskate and tree hugger in me make me run my tires down more than 50%. Passenger car tires usually start our at 9/32nds to 10/32nds inch of tread. I used to go down to 2/32nds inch, the legal minimum. But, now my goal is 3/32nds inch. When my tires are old, I slow down more in the rain, though. Locally, if it's raining I take my car with the most tread on the tires. The boundary between safe and unsafe, and most self-imposed boundaries for that matter, is somewhat arbitrary.

Most tires lose grip on dry pavement with use. The rubber gets harder and less "sticky." Touring (low-performance) tires have less adhesion than high-performance tires. Those LS2's that came on my 535i were low-performance. One could logically argue that high-performance tires are safer. But, how safe is safe enough? The first time I was screwing around in the my 535i, I got the car a little sideways without even trying. Doing the same maneuver in my old M3 with PSS's was uneventful.

My old M3 had Pilot Sports. They were noisy when worn out. My beater has Continental DW's. I've taken one set down to an average tread depth of just under 4/32nds inch and they were fine. I probably would have worn them down some more, but one of them had a puncture repair fail. They were far enough gone that I just replaced all four tires. I still got 40k miles out of them. I'm now on my second set of DW's. At 25k miles, they have an average of about 6/32nds inch of tread left. When I get 40k miles out of the second set of DW's, I'll sell the car.

The Nissan Cube's look more like clothes dryers. The Honda Element is the one with a roof arch like that of a toaster.

https://youtu.be/7geyX1Er1zs
 

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Back on topic....has anyone with a X3 M40i, 20 inch rim and big brakes able to find a spare tire kit? The ones in Bimmerzones wont clear the big brakes.
 

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BMW offers the optional spare tire on the M40i. The spare on the 30i is comes on an 18" rim. A dealership could easily find out if it's the same spare tire and rim on the 30i comes on the M40i.

Two of BMW's winter tire and wheel packages for the G01 X3 M40i come on 18" rims. So, that's a good indicator that the 18" spare tire rim would also clear the M40i's larger brakes.

I have the "master broadcast sheet" for Frau Putzer's X3 30i. The master broadcast sheet is sort of the assembly instructions for building the car. The spare is listed as option code 300 and just says "Emerg Wheel" not "Emerg Wheel 30i." The option codes for the spare on the 30i and the M40i are both "300." So, that's another indication that the 18" rim might work on the M40i.
 

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For anybody ordering a new X3, think real hard about the optional spare tire. At $150, it's the biggest bargain in the list of options. The spare is free if you order the non-RFT's on the 30i (Code 25X).

It does raise the cargo area floor up about five inches. But, I actually prefer that the cargo floor is higher than the opening. That makes it easier to get stuff in and out.
 

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For anybody ordering a new X3, think real hard about the optional spare tire. At $150, it's the biggest bargain in the list of options.

It does raise the cargo area floor up about five inches. .
Absolutely.... do it!! And if you get a cargo mat....get the WeatherTec. You will hate the BMW OEM mat.
 

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What brought you to that conclusion (that the item is discontinued)? If it is the "note" at the bottom of the part nbr index...then that is just a description to explain what "ENDED" means for one of the listed part nbrs which would be for item #3. BMW ended the part number for the 1st listing for #3...but gives the new number for #3 in the next line below the "ended" number.

Click the link again to the realoem.com website and take another gander at the part number index. The only thing I can see that is discontinued is one of the 11 digit part nbrs for the first listing for #3...but anther replacement part nbr (for #3) is given below the discontinued number. And the note at the bottom of the part number index is there to explain why "ended" is listed in the note section for the 1st listing of #3. :)
 

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Why not buy a full size wheel and tire? The overall size should be very close to a donut. Anyone tried?

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