How do I know which wheels I have (TRX vs R15)?

[vt]

Sigh, been trying to find the answer for several days now, no FAQs seems to have it or I'm too blind to see, local shops have no clue either... So here goes -

(/me dons a fireproof jacket)

The 535i we've just bought (our first E28) has, among other stupid things that five previous owners did to it, three tire sizes on it: three 205/60R15, fourth (left rear) 195/65R15, and, drum roll, the original TRX 200/60VR390 spare.

So now I'm trying to figure out why in the world someone would willingly install *one* different size tire, and what wheels do I actually have. Specifically,

- Is there anything special about rear left wheel well that would not allow a 205/60R15 tire to fit, with a slightly lowered suspension (thinking about reverting to standard size, but there's a loooong list of things to fix first);

- Is it possible that someone managed to stretch R15 tires onto original TRX wheels? Seems to defy common sense, but, like I said, turned out that there's been a lot of stupid things done to the car (like this: http://tinyurl.com/d4voev), and seeing tyrestretch.com doesn't add any confidence either.

- In other words, is there a way to find out what wheel I have without taking the tire off?

Best guess is that I read the wheel markings correctly:

This one says 165TR390CW: http://tinyurl.com/camp5b - TRX
This one says 7J 15 H2: http://tinyurl.com/cxg9vh - R15

--vt, paranoid mode
http://e28diaries.blogspot.com/

[mooseheadm5]

Probably had the TRX spare and threw that on there after slamming a curb or something. Buy a set of wheels (E32/34 basketweaves are nice for daily drivers) and some new tires and be happy.
Tire stretching means narrow tires on wide wheels. You cannot put a TRX tire on a regular wheel or regular tire on TRX wheel, so no worries.

[j.bavarian]

The 165/TR390CW is the TRX wheel. Leave the damn thing in the boot for a spare and get all new tires! Stay with the 205/60R15.

[C.R. Krieger]

Although photos might help, you are reading those wheel sizes correctly. The highest and best use for the TRX is living under your trunk floor, and there is probably nothing too wrong about that odd tire. It is pretty close to the right size compared to the other 3. Probably thrown on as a cheap solution when a match was unavailable.

The question is, do the 15" wheels look the same? Further, do they look at all like the TRX? The TRX is usually called a 'bottlecap' because the center sort of resembles one. I don't think there is a 15" bottlecap wheel to fit the E28 (although there is a 14" that came on many 528es). For general street use, there is nothing seriously wrong with a 195-65 or even a 185-70 on a 15" wheel for an E28.

[vt]

C.R.: Glad to see you're still around

Photos - hmm, there were links to them in the message, guess that's not the way it's done here. Let me see the FAQ and correct the blunder.

TRX for the spare - I really doubt that any of the owners would go for the new tire, so it's probably been there for the last 22 years. I remember hearing that after about 6 years of shelf life you better throw the tire out, or it's still reasonably safe to be used as a spare? I'd rather buy a cheap R15 rim and tire and carry that around instead - unless you guys talk me out of that.

15" wheels look all the same (style 5), TRX is different (style ... all right, I see the light now, TRX-2, wish I've thought of looking it up before - http://felgenkatalog.auto-treff.com/).

[mooseheadm5]

Those are E32/34 basketweaves, which are plentiful and cheap. Buy another 1 or 2.

[vt]

mooseheadm5: there doesn't seem to be anything wrong with those wheels (at least, for now - I haven't taken them off yet). I guess I'll just leave them where they are.

[mooseheadm5]

I misread. I thought for some reason there was a TRX on one corner, not an odd sized tire. I'm kind of awake now. You can either can the spare and buy another weave or leave that thing in the trunk.

[vt]

mooseheadm5: speaking of which, any good place to buy a wheel? Or that is a FAQ item? (gone looking)

[ismellfish2]

Were you chasing skirts at a Renaissance Fair?

Ideally, you would buy another 15" basketweave (should cost about $50), and at least two tires in 205/60, so you can have five matching wheels and tires. You could just pick up one tire, for the left rear (which will fit fine) and keep a TRX spare. There's nothing really wrong with doing this, except that you have no guarantee that that 10 to 25 year old tire won't blow out when you go to use it.

[MrNic3Guy]

I don't know, but they're some hot woman in your tinyurl link.

[C.R. Krieger]

C.R.: Glad to see you're still around

Photos - hmm, there were links to them in the message, guess that's not the way it's done here. Let me see the FAQ and correct the blunder.

Yeah; they try to chase me away, but it's hard. I didn't get the pix because I was reading/posting from my phone and I have no tabbed browser there. My mistake. Yes, those are the wheels others have told you.

TRX for the spare - I really doubt that any of the owners would go for the new tire, so it's probably been there for the last 22 years. I remember hearing that after about 6 years of shelf life you better throw the tire out, or it's still reasonably safe to be used as a spare? I'd rather buy a cheap R15 rim and tire and carry that around instead - unless you guys talk me out of that.

Be cheap. Keep the TRX as a spare. You may never need it at all. If you do, treat it gently. No burnouts or autocrosses.

[vt]

ismellfish2: yes, along with my wife and two kids Seriously, though? I used to shoot mostly landscapes till the digital cameras came, now trying to regain what I waisted and shoot faces instead - more variance and more challenge (come on, y'all bimmerheads know what that is, right?). And with my chromosome set, people would look at me funny if I was shooting boys

MrNic3Guy: yes, that's my SWMBO

C.R. dunno, your attitude's been fine in my book

[MrNic3Guy]

[Shawn D.]

... R15...

FYI, there is no such thing as an "R15" wheel. The "R" is denoted in the tire type. Given the lack of bias-ply tires in metric fit designations, the R is pretty much redundant anyhow these days.

[Geerhed]

I used to shoot mostly landscapes till the digital cameras came, now trying to regain what I waisted and shoot faces instead

Sure... faces attached to hot females with exposed cleavage. Very challenging; especially when their burly boyfriends take exception to your artistic endeavors.