My 530 actually has a (doughnut) spare in the trunk. I wanted to replace it with a full size. Is it possible with a 17 or 18 inch rim with maybe a smaller size tire?
The original is rim style 123. I currently am running the 166 style rim. They are 19's but would like a full size just in case to be able to drive comfortably on the freeway if possible to get back home for instance. Thanks.

 

What are you trying to accomplish? The purpose of the doughnut spare is to get you to a destination where you can address the failed tire and replace it. It isn't meant (or recommended) that you drive on it for any distance or length of time. Your car needs to have the same tires on all four corners to perform properly. To just have another full-size spare tire and rim that doesn't match the other four will defeat the purpose.

To see if your tires will fit, simply measure them. I don't think they will fit in the well.

 

Right I agree with having the same for all 4. But when it's 1am and there are no tire shops available and you are about 1.5 hrs away from home, driving less than 50mph can be really tedious. So by having a full spare will help you get to your destination safely.

Maybe can look into the rims that are on the i3 lol, they look like 185/40/19.

Not sure if the M5 has a spare and a spare that will be for a 19"rim combo.

 

If you think about this rationally, how often do you think that the scenario you painted would occur? I myself haven't experienced a flat tire in 20 years, and NEVER with the two Bimmers I've owned. Maybe I'm just fortunate, but my point is that your trunk space is what it is, and you're going to limit it even more by providing for an event that is less and less likely to occur as the quality of tires improve.

So I guess you could just pick up another 166 rim, buy a duplicate tire and call it a day, or change out all of your tires for runflats, but then that opens up another whole can of worms. Or just save your $$$ and rely on the doughnut spare to do it's job if and when it is ever needed.

 

lol, the scenario that I described occurred 3 days ago for me. So it can happen. For me, it did happen. Yes you are very fortunate that in the last 20 years and with 2 BMW's you never got a flat tire.
Yes, run flats are great. I have had 2 sets of them. But with 2 sets of run flats and with 3 cracked rims in total due to run flats I decided to not pursue purchasing them again as the cost of ownership in my case is much more.

For me safety is much more important than $.

Thanks for your opinion.

 

Well I am with Jay on this one.

I have driven over 1,500,000 kms on 8 BMWs over 45 yrs and have not suffered a flat that couldn't be handled by reflating the tire enough (using a small portable 12 v air pump) to get me where I needed under those circumstances.

Besides, you have had your one in a million incident , so I wouldn't go through the hassle and $ for this.

Salut, Bob P.

 

That's great. You guys must be extremely lucky. As I'm not able to control the debris that get left in the streets and freeways I can only deal with them as they are before me.

The debris that was in front of my tire which caused a 3 inch (7.62cm) hole on the side wall and tread area is far from being repaired. Yes I am ready ready for flats. I have a compact air compressor, I have a can to inflate a tire with slime (although it's bad, I have it as a just in case). I also have a patch kit in the trunk as well.
The only thing I don't have is a regular tire. That's why I jumped on the forums to see if the rest of the population has encountered a flat tire that wasn't replaceable.

If I'm the only one that encountered this. I might as well go buy a lottery ticket, my odds of winning just increased dramatically!

You can not have a solution for every obstacle that gets thrown at you. You however can be well prepared for most.

 

Like I said, your best bet is to just purchase another tire and rim that matches your set and be done with it if that makes you more comfortable.

 

I know that, that is an option. However when you look at the trunk where the spare is you can notice that the area that it gets housed it will not support a 19 inch rim with 245/35/19 tires in it.

That's why I jumped on the forums to see if anyone as done a spare/full size with a 17or 18 inch maybe 7.5 or 7 inch width rim and tire setup.

There are actually several car forums that have the same solution I am looking for. However it's a different car and fitments are different. Some have found a wheel and rim combo for perfect figment in their compartment. Some have raised the trunk floor with foam inserts to accommodate the larger width rim/wheel.

Since other vehicle forums had them I figured why not ask the people on this forum.

 

Is the current rim/tire combo too high or too wide?

Is your car AWD or RWD?