Do you think that you could use a 20" front rim as a spare on the rear?

[Barbja]

Background:

1) I'm going to order 20" wheels on my X. Performance tires are not for me so I'm going to order Conti DWSs to go on them. As most of you know, those are not run-flats.

2) I don't want to get a space-saver spare because I really don't see the point. Even if I could change the tire myself, I couldn't get the flat one into the trunk; I can barely lift my 28lbs of bowling balls into the trunk so 50+ lbs of flat tire would be impossible. So I'd have to call service or a friend to help anyways. And even then, since the wheel won't fit in the spare compartment, where is it going to go? In the back seat? On the roof? You'd say "throw it in the back"...right... And then where does that stuff go?

3) In my 30+ years of driving, I've never had a flat more than 10miles from my house. Most of them have manifested themselves in my driveway.

4) With my E53, I was able to get tires for it right away. However, when I've had a flat on an E70s+ that were not repairable, they've always had to order a tire and I've had to wait at least a week to get it. I have to fill the tire up 2x a day and not go very far until the tire comes in.


Here's a crazy thing that I'm thinking of doing:

1) Order one front wheel that matches my others. (Or any full-size rim actually. I guess it doesn't even have to be 20". Just a front.)

2) When I get my Contis put on, keep one of the fronts with the RFT on it and have the Contis mounted on the other 3 plus the new one.

3) Save all the RFTs to put back on the car when its traded in because the ones on the wheels will probably be toast.

4) Keep the wheel with the RFT at my house to put on the car if I get a flat.

5) If I get a flat at my house, I can just switch out the wheels. If I get a flat away from the house, either have someone bring the spare to me (and they'll have room for the flat because they brought the spare to me! Ex husbands are good for this.), or have my car flat-bedded to my house.


So here's the question:

Can I mount a 20" front wheel on the back? If so, can I put it straight on there or would I have to use spacers? I suspect that you can since you can put a space-saver spare on there.

I understand if I do this I wouldn't be able to drive the same as I normally would, but it would be a heck of a lot safer than driving on a space-saver spare, yes?

Opinions? Am I bananas?

[r33_RGSport]

@Barbja,
Yes, you can put the front wheel to the rear. That's the setup on the non-staggered, front and rear are the same size and offset.

[AEC]

My advice is just to get the space saver spare if you are switching away from run flats. The main advantage over your plan is that the spare is always in the car. Even if you can't change the tire or put the damaged wheel and tire into the car, roadside assistance can. If you don't have the spare with you, someone has to bring it to you which may not always be possible in a timely fashion, leaving you and the car stranded.

Many people criticize run flats for many reasons, but there are some definite advantages. I really like knowing that if my wife or daughter is driving when a flat tire occurs, they can just drive the car home and not have to deal with the issue in a potentially dangerous location or in really bad weather.

Does the weather in Austin not allow for performance tires year round? I'm asking because I don't know.

[Barbja]

Interestingly on the X6, in a non-staggered setup, the wheels are not interchangeable. The wheels have different part numbers; I had always though that was odd. It turns out that the rears have built-in spacers.

I had stock 19" on my last X6 and the shop rotated them because it was out of alignment and had chewed up my front tires. My rears were excellent so they switched 'em. They rolled it out of the shop and thought something looked funny. The fronts were out too far and the rears in too far. They had to switch them back.

Weird. Now they know not to rotate 19" X6 tires (wheels)!

[Barbja]

Originally Posted by AEC

My advice is just to get the space saver spare if you are switching away from run flats. The main advantage over your plan is that the spare is always in the car. Even if you can't change the tire or put the damaged wheel and tire into the car, roadside assistance can. If you don't have the spare with you, someone has to bring it to you which may not always be possible in a timely fashion, leaving you and the car stranded.

Many people criticize run flats for many reasons, but there are some definite advantages. I really like knowing that if my wife or daughter is driving when a flat tire occurs, they can just drive the car home and not have to deal with the issue in a potentially dangerous location or in really bad weather.

Does the weather in Austin not allow for performance tires year round? I'm asking because I don't know.

Don't you think that I can get someone I know to me faster than roadside assistance? Last time, my 'person' was there within 15mins, then we had to wait an extra hour after that for the flatbed to come. My sister could have driven from San Antonio almost as fast as it took for the tow guy to get there. (This was an accident, not a flat tire though).

We get snow (rarely), sleet, freezing rain, hail, and floods. Perhaps a tornado or two, but no tire is going to help me in that situation.

Besides the fact that I don't want to worry about my tires in bad weather, I'm really hard on tires and don't want to replace them every 10k miles. I'd rather shoot for 25k. That's been about my limit on every tire I've ever had except the ones I had on my E53. I could get 30k on those and never even had to be rotated.

I usually get Michelins, but have strayed to Contis, Dunlops and Yokohamas. So the issue is me, not the manufacturer.

I wish that they made all-season run-flats for our 20" rims. I'd do that in a heartbeat.

[AEC]

Originally Posted by Barbja

Don't you think that I can get someone I know to me faster than roadside assistance? Last time, my 'person' was there within 15mins, then we had to wait an extra hour after that for the flatbed to come. My sister could have driven from San Antonio almost as fast as it took for the tow guy to get there. (This was an accident, not a flat tire though).

It all depends upon when and where you get the flat. If you are out of town, late at night are you going to call someone to drive to your house, pick up your spare tire and then drive to where you are so that they can help you? Just because your previous incident occurred in a relatively convenient time and place, it doesn't mean the next one will.

If you don't have a spare or run flats, there is very little that roadside assistance can do other than flatbed the car to a local service center.

[Terp335]

Couldn't you use fix-a-flat or something similar if you didn't have a spare and ditched your run flats? While not a perm fix, and wouldn't work in all situations it could by a viable option, right?

[AEC]

Originally Posted by Terp335

Couldn't you use fix-a-flat or something similar if you didn't have a spare and ditched your run flats? While not a perm fix, and wouldn't work in all situations it could by a viable option, right?

Those types of products may help for a small puncture, but wouldn't help for a larger tear or blowout. Also, many if not all of those products will damage the TPMS sensors, often requiring them to be replaced.

[opasha]

Is the center bore different for the back wheels compared to the front wheels? That could be the cause as to why you can't interchange them. I know the X5M previous model has 74.1 center bores in the front and 72.6 center bores in the rear...this requires modification of the rim (basically shaving the rim to 74.1 - ruining the rim).

[chrisny]

Based on all of the information you're giving, all things considered, I'm not understanding why you don't just stick with the run flats.

[r33_RGSport]

Originally Posted by Barbja

Interestingly on the X6, in a non-staggered setup, the wheels are not interchangeable. The wheels have different part numbers; I had always though that was odd. It turns out that the rears have built-in spacers.

I had stock 19" on my last X6 and the shop rotated them because it was out of alignment and had chewed up my front tires. My rears were excellent so they switched 'em. They rolled it out of the shop and thought something looked funny. The fronts were out too far and the rears in too far. They had to switch them back.

Weird. Now they know not to rotate 19" X6 tires (wheels)!

As @opasha mentioned, the E71 X6/X6M and E70 X5M, do have different wheel center bore between front and rear. That is not the case with F15 X5, and looks like the F16 X6 also.