Spare Tire - No Longer Made?

**rufusdog** · 08-07-2022, 06:15 PM

My wife and I were out for a ride yesterday when i heard a sound like a flat tire. Turned out it was just a bad patch of road, but it got me thinking about my 20 year old spare. When I got home I dropped the spare and checked the pressure - zero. Still looked like new. I filled it and a day later it's still at 61PSI. Went looking for a new tire since it's not smart to trust a 20 year old tire and I can't find a single seller that has a T 115/90 R16 tire. Lots of 125/90 R16s. I tried to fit a spare from another of our cars (125/90 R16) and its just too big, even deflated. Anyone have a lead on a new T 115/90 R16? I do have the BMW mobility kit in the trunk and that's fine for punctures, but anything bigger than a nail and it's no use.

**Hoyt Clagwell** · 08-07-2022, 08:50 PM

'just a thought but you could probably get a CAA membership (AAA in the States?) for less that the cost of a new spare and not have to find yourself changing a tire in the pouring rain at night.

**rufusdog** · 08-08-2022, 08:11 AM

Originally Posted by Hoyt Clagwell

'just a thought but you could probably get a CAA membership (AAA in the States?) for less that the cost of a new spare and not have to find yourself changing a tire in the pouring rain at night.

Used roadside service for my Porsche a few years ago....3+ hours waiting on the beltway. Metro areas can take a while for a truck.

**ddbaker3** · 08-08-2022, 11:26 AM

It seems like 135/80 r16 comes really close to the original size, just a fraction larger in diameter and width. Or there are some options at 125/70 r16 that would be noticeably shorter, but should fit in the carrier and would give you something to roll on for a few miles. I'm not sure if having one wheel at a smaller diameter could do any damage.

**khammack** · 08-08-2022, 11:56 PM

Has anyone thought of what they will be doing with the flat tire. It may not fit in the trunk. The one time I had a flat in my Z3 (it was the smaller front tire), I was able to use the spare tire, but the flat tire would only go in the passenger seat. Glad I didn't have a passenger on that day.

**mpire** · 08-09-2022, 09:39 AM

The stock wheel/tire should fit into the trunk.

Have you tested this out?

I keep a spare factory BMW tire bag for these situations.

**khammack** · 08-09-2022, 01:26 PM

The car where I had the flat was a 2002 Z3 and the front tire would not fit into the trunk.

**cyberman** · 08-09-2022, 03:27 PM

There are many threads here on this subject. There is/are some tires in production that will fit on the spare tire rim. I, and many others decided to ditch the spare and its carrier and figure if there is a major blow-out that a patch kit can't fix, well if we're close to home, a tow truck is the best option. If very far away from home, I'd be reluctant to drive on a tiny space saver spare anyway so a tow truck to the nearest shop is probably also the best option. It's a gamble on saving money and time and each person must weigh the risk for themselves.

**rufusdog** · 08-09-2022, 05:01 PM

I went with this solution I found on Amazon. Took it out of its carrying case and it fits perfectly in my 20 year old BMW mobility kit case. It has the Euro style warning label and the filling agent purports to wash out so the tire can be repaired/reused. Stores for 6 years and costs a little more than new filling agent for the BMW mobility kit.

I've had this Z3 since it rolled off the truck at the dealer in late 2001 and have kept it original (with minor upgrades) and like-new. I'll continue to look for a spare that fits the compartment and will post results here.

spare_.jpg

**ZGator** · 08-10-2022, 11:45 AM

I remember when I bought mine new the salesman showed the tire bag that would hold the tire and need to be placed on the seat or on the lap of who was sitting in the seat.

I checked mine too probably over a decade ago - it was flat as the great salt lake, with about 5 lbs of gravel were in the tire holder too - you would think I did a lot of off-roading.

But as a PSA - check your spare or at least add air to it - I think you can do that without removal - I recall there is a pass through valve?

**rufusdog** · 08-10-2022, 12:31 PM

Originally Posted by ZGator

I recall there is a pass through valve?

On the back driver's side of the spare compartment there's an air valve that goes to a hose that goes to the spare tire's air valve. Nice in theory, but another point of failure and something else to disconnect in the event that you need the spare.

**z3forlife** · 08-10-2022, 02:06 PM

I found that the hose corroded to the valve stem on my old 2.5. I had to cut the valve stem and have a new one installed in the rim. Just another routine maintenance issue with these cars.

**wildspeed** · 08-10-2022, 03:00 PM

I replaced the original 15' spare with a Kumho 121 T 125/80D16 and BMW 36-11-6-750-006 wheel

Won't fit in the tray fully inflated (60PSI), but fit at 30PSI so you still need to carry a compressor.

**khammack** · 08-10-2022, 04:27 PM

I know everyone has their own experiences, but I wonder how often, on average, do we get flats on our little cars.

For me, after about 150K and 20 year on my M Roadster I have never had a flat (hope I didn't just jink myself!), and with my Z3 (prior to my M Roadster) I only had one flat and that was because Boulder, CO had rotomilled a road and left the man-holes about 4 inches above the road surface.

Luckily I was going slow in traffic, but unluckily I didn't see the manhole soon enough (it looked like I was about to hit it with my bumper). I was almost able to swerve and miss it. Ended up just catching it with the edge of my tire and wheel and cut the sidewall, but didn't damage the wheel.

I guess my point is, in my case, I have not needed a spare tire in 20 years, so I'll just stick with my plug kit and a small compressor or AAA if I can't plug it and I'm just asking if all the work trying to find another spare tire and then deal with the flat tire is really worth the effort?

**rufusdog** · 08-10-2022, 04:41 PM

We all have different comfort zones. Like carrying a fire extinguisher in the car. I have a Halon extinguisher in a bracket bolted in front of the passenger seat. Have never needed it but if I do, it's there.

**Truckeeskibum** · 08-10-2022, 05:41 PM

I also went with the Kumho 121 T 125/80D16 and BMW 36116750006 wheel.

You can get the unit to fit in the under trunk tray at normal pressure. You just need to take a saw and cut a couple of reliefs in the vertical wall of the tray.

FWIW, I just used a manual hacksaw. It probably took me about a minute (maybe two) to make the cuts.

**Randy Forbes** · 08-10-2022, 07:01 PM

Originally Posted by z3forlife

I found that the hose corroded to the valve stem on my old 2.5. I had to cut the valve stem and have a new one installed in the rim. Just another routine maintenance issue with these cars.

I don't think I ever found a Z3 spare tire with air in it (I removed the spare on every car I'd work on, so felt obligated to check) and I too maintained that it was the interconnecting hose that was the culprit. Although one car, the valve stem was so dry rotted, it fell apart in my hand when I tried to put the air in!

**ZGator** · 08-10-2022, 08:27 PM

Originally Posted by khammack

I know everyone has their own experiences, but I wonder how often, on average, do we get flats on our little cars.

For me, after about 150K and 20 year on my M Roadster I have never had a flat (hope I didn't just jink myself!), and with my Z3 (prior to my M Roadster) I only had one flat and that was because Boulder, CO had rotomilled a road and left the man-holes about 4 inches above the road surface.

I got you beat 22 yr 163k no flats, thank god, knock on wood..

thanks in advance for all the helpful post!

LOL I just know mine is flat again, will report back with inflation pressure and gravel lbs..

<UPDATE>
Yep mine was almost totally flat.

5 of the required 60 psi pressure on mine, granted it's been a decade or longer - and I should have been topping it off which I admit I never do - I did disconnect the external air line hose - hope that helps, I have a feeling it will lose quite a bit on it's own though being so skinny and at 60 psi.

PSA2: To drop the spare down - there are 2 release points -one near center of the car and one to the right - underneath the little compartment - the one near the center you screw in the cable to lower the spare AFTER you release the right nut.

**rufusdog** · 08-22-2022, 11:34 AM

The Kumho 121 T 125/80D16 fits like the original. Thanks for the outstanding suggestion.IMG_2630.jpg

**Lotsaputts** · 08-22-2022, 12:42 PM

One of my to-do's is to check the spare. Thanks for all the info that prompted me to change from to-do to "must".
Dave

**sleeperz** · 08-22-2022, 02:47 PM

Have you inquired about ordering one of these? I assume they are still produced?
https://www.henisetire.com/tires/vie...t17-115-90r16/

**Hoyt Clagwell** · 08-22-2022, 03:10 PM

Originally Posted by sleeperz

Have you inquired about ordering one of these? I assume they are still produced?
https://www.henisetire.com/tires/vie...t17-115-90r16/

I noticed it said something about only using it for only one wheel position. I suspect that is because, once spun in one direction, spinning it the other way can throw the belts. (ask me how I know) If that's the case, keep in mind that it is basically a one time use item. I suppose after using it, you could mark the direction and hope that if you ever need it again, it will be on the same side of the vehicle.

**Pima Roadster** · 08-22-2022, 07:37 PM

A good conversation here about spare tyres. I have carried a Conti Comfort Kit for years in the boot of our Z3. Unfortunately the sealant is past date & no longer available from Continental which is a bummer. @rufusdog, that kit looks good & might be the replacement. I too spent much time looking for a replacement spare tyre with little success. The Kumho is the only one I came up with from my searches. Not certain if it matters, the tyre is not a radial. Our Roadster is rarely driven- driving in SE AZ is not scenic so local runs of 100 miles round trip at the most is all we do. Holding on to the Roadster in hopes of moving eastward. IF I was to travel longer distances, as the OEM 17" wheel will not fit anywhere & the Mrs. will not stand by the side of the road whilst the flat spare takes her place, I would consider locating a luggage rack that is not permanent so that the wheel could be stowed there in the event of a non-sealable failure.

**Pima Roadster** · 08-22-2022, 10:18 PM

So time, too much time on more research on this issue today. Apparently the Kumho T125/80D16 is currently unavailable & the OEM Continental 115/90R16 is discontinued. The former is available on EBay but NOS 7 years old. There is a Maxxis tyre available in the T125/80D16 but look at the diameter for the size in this chart. https://www.maxxis.com/us/tire/compact-spare/ Much smaller than the OEM.
I use this website for tyre size comparisons.
https://www.tacomaworld.com/tirecalc...0r16-125-70r17 I have not found a Continental website which gives the original diameter & width of the T115/90R16. However if I look at the dimensions of the 125/70R17 here, sorry for the long link, the size is very close to that given in the comparison chart & close enough for me.
https://www.tirerack.com/tires/tires...!&gclsrc=aw.ds
Do note the diameter of the 125/70R17 tyre which is very close to the Z3 original spare, 23.89" vs. 24.15". The width is a little fuzzy as to how it is measured, tread width or tyre width but the difference is approx. .50". Question here is will this make a difference when the carrier is raised into position with this size of spare? As you have likely noticed, I am looking at a 17" replacement tyre. Perhaps someone can confirm that this rim will fit on a Z3 as to the wheel stud pattern & ET.
https://www.turnermotorsport.com/p-6...uine-bmw-part/ This rim is 3.5" wide vs. the Z3 which is 4.0" & the offset is 30MM. Not certain what the offset is on the Z3 rim. In summary, I like the idea of moving up to a 17" rim to use the Continental replacement spare if the lug pattern & the width of the tyre are not an issue. So I am looking forward to feedback from you folks, do not hold back! TIA!

**rufusdog** · 08-23-2022, 05:33 PM

Originally Posted by Pima Roadster

Apparently the Kumho T125/80D16 is currently unavailable & the OEM Continental 115/90R16 is discontinued. The former is available on EBay but NOS 7 years old.

I just dropped the spare to check the date code - manufactured 3rd week of 2022 - so this is a fresh tire. I bought it on ebay from simpletire. They have none in stock right now. They had over 20 when I ordered mine so I'm guessing the Z3 community bought them out

.IMG_2631.jpg