996 turbo spacesaver spare - The Unofficial BMW M5 Messageboard (m5board.com)

stever · 5th May 2001, 00:21

I finally found the measurements I took from Greg's spare last November. It looks like it will work but it's not entirely simple.

The Turbo has about the same weight on the rear as the M5 on the front and the inside diameter of the Turbo spare wheel is about the same as the inside of the M5 wheel (although the Turbo spare is a 165/70-16, the wheel doesn't have a drop center) so brake clearance is fine.

But of course the bolt circle is different (Porsche 130mm, BMW 120mm) so a wheel adapter is required. The adapter is a little over 1 inch thick which is okay since the BMW front tire is 1.62 wider on each side than the Turbo spare (which also has less positive offset than the M5, .40in.vs .78in.). Clearance is okay, but with the spacer the Turbo spare on the front will have a .6 NEGATIVE offset which will affect steering --- but having a space saver on one side will anyhow and we're talking 50mph max for 50 miles as I recall (Greg, is that right?)

The one dimesion I don't have is the overall diameter as stored deflated (I think it's about nineteen inches -- Greg, could you check this also). The width is 6.2 inches for a volume of .8 cubic feet -- this is less tnan 1/3 the volume of the BMW front wheel/tire assembly.

Now the bad part. Porsche wants $565 for the wheel and tire assembly P/N 99636205000 (Wheel Enchancement in LA will knock 10% off this).

The spacer is $65 (+8% CA tax in CA) +$25 shipping prepaid by check or money order to
Design Deluxe Mfg.
21300 Deering St.
Canoga Park, CA
91304

To mount the spare, you bolt the spacer on with the M5 wheel bolts, then put the spare on with lug nuts (the lug nuts are supposed to fit the BMW lug wrench, but I can't swear to it --the spacer has studs on the Porsche pattern) --and you blow up the spare with you handy M5 pump. Of course you need a jack (which will fit inside the Porsche wheel) and a lug wrench.

Does anybody have a better idea before I spend $600+?

I tried the M5 front wheel as a spare and it really does chew up the trunk room. Driving without a spare is nervous making in areas many miles from service with no cell coverage.

greg · 5th May 2001, 02:25

Steve - I just went outside and measured it. The outside diameter of the collapsed Porsche spare is about 20 1/8"

/Greg

stever · 5th May 2001, 18:08

Thanks, that makes the volume about 1.13 cu ft, saving 1.3 cu ft over the M5 front wheel and tire. That's a pretty expensive 1.3 cu ft.

Panos · 10th April 2008, 01:31

Is there a cheaper solution that this for a space saver spare tire?

gsfent · 10th April 2008, 16:09

Quote:

Originally Posted by Panos

Is there a cheaper solution that this for a space saver spare tire?

Try ebay, I paid a LOT less than $600....
Regards,
Jerry

mottati · 10th April 2008, 19:26

Quote:

Originally Posted by Panos

Is there a cheaper solution that this for a space saver spare tire?

i'm not sure if the above from 2001 was ever proven to work? Most of us use an old front wheel and tire. Alternatively, you could find a bmw style 66 wheel which is 17", so a bit smaller and potentially cheaper. A few other 17" wheels can fit as well.
I only use mine when i'm taking a trip, otherwise it sits in my garage.

Panos · 10th April 2008, 21:08

Quote:

Originally Posted by mottati

i'm not sure if the above from 2001 was ever proven to work? Most of us use an old front wheel and tire. Alternatively, you could find a bmw style 66 wheel which is 17", so a bit smaller and potentially cheaper. A few other 17" wheels can fit as well.
I only use mine when i'm taking a trip, otherwise it sits in my garage.

Was hoping for a space saver to.... save trunk space. i dont really want a full size in the trunk, since there is not a wheel well for it.

Jack Fishman · 10th April 2008, 21:19

I had Art Spence of Motorsport Technology - 714-553-3910 make me a custom spacer to go along with a Mercedes donut spare tire he supplied. It is considerably less than $600. I use elastic tiedowns in the trunk to hold it in place.

gsfent · 10th April 2008, 21:42

Quote:

Originally Posted by mottati

Alternatively, you could find a bmw style 66 wheel which is 17", so a bit smaller and potentially cheaper. .

Hmm, assuming you don't change the rolling diameter, wouldn't the overall package size be the same? Smaller wheel, but slightly taller tire to stay around 25.7 inch rolling diameter. I guess the package could be narrower.....
Regards,
Jerry

Panos · 11th April 2008, 00:03

Quote:

Originally Posted by gsfent

Hmm, assuming you don't change the rolling diameter, wouldn't the overall package size be the same? Smaller wheel, but slightly taller tire to stay around 25.7 inch rolling diameter. I guess the package could be narrower.....
Regards,
Jerry

Thats what I am thinking. Keeping it narrow, would be nice so you still have trunk space.

gsfent · 11th April 2008, 00:50

Quote:

Originally Posted by Panos

Thats what I am thinking. Keeping it narrow, would be nice so you still have trunk space.

Still takes up a lot of space.
I am experimenting with a 996tt space saver. I had it redrilled to accept the BMW spacing and now just working on the spacer. I have studs, so I will bolt the wheel to the spacer and then simply mount it like a normal tire.

I am hoping it will fit the front BBK which goes under the stock wheel. Should be done in a couple of weeks. I

I am going to see if I can fit it under the deck, where the M mobility kit goes.
Regards,
Jerry