Wheel/Tire mystery

[wyovino]

I need new rear tires on my 2000 C2. I have what's listed on the original sticker as "18" Lt Alloy Wheel - Turbo Look". These are the wheels shown in the attached photo.

The front wheels are 7.5J x 18, RO 50 with Continental SportContact2 N2 225 / 40 ZR 18 Tires

The rears are 9J x 18, RO 52 Continental SportContact2 N2 265 / 35 ZR 18 Tires

The fronts are fine, but from what I've read, the rears are for a Boxster, not a 911, though the tires are the proper size for a 911.

I bought the car from the original owner (a friend of the family) who is a very wealthy, spare-no-expense, let the dealer do everything, type of person. I don't believe there is any possibility that this person would have gone for a cheaper alternative with something like wheels.

So there are a few possibilities that come to mind.

1. Could it be that in 2000, 9J x18 x 50 rears were approved for 911? The TSB that I've read is dated June, 2011.

2. The dealer could have used a boxster wheel unintentionally or otherwise.

3. The car came from the factory that way (by mistake).

Now the question is "What do I do"?

I have a set of winter wheels/tires on the car at the present time (8J x 18, RO50 and 11J x 18, RO63)

1. Get new rear tires and have them mounted on the 9J x 18 x 50 original wheels. (which I assume have been on the car for 12 years)

2. Get four new tires and use my winter wheel set.

3. Look for a set of replacement rear wheels in 10J x 18 x 65.

I'm looking for the cheapest safe solution.

Edited March 19, 2012 by wyovino

[Loren]

I don't recall Porsche ever offering 9 x 18 rear wheels for the 996. 9 x 17 and 8.5 x 17 rear winter wheels - yes but no 9 x 18.

I had a similar issue on my car when I bought it. I opted to trade them in for 8 x 18 fronts and 10 x 18 rears. Wheel Enhancement gave me a good trade-in price as the wheels were in very good shape.

I suspect that a dealer had swapped wheels with someone that really liked the ones on my future car.

[wyovino]

Ok, thanks, but more questions. Sorry, but I'm not very familiar with tires/wheels. I think tires and wheels used to be a lot less complicated when I was a teenager (don't ask).

My winter wheels have the same size tires as my summer wheels (225/40 18) even though the wheels are different widths (8 vs 7.5 ).

I'm thinking of transferring my good front tires from my summer wheels to my winter wheels. Then I could just buy two new (summer) tires for my rear winter wheels, and sort the summer wheel issues out at a later date.

Does this sound like a good plan?

[Loren]

Ok, thanks, but more questions. Sorry, but I'm not very familiar with tires/wheels. I think tires and wheels used to be a lot less complicated when I was a teenager (don't ask).

My winter wheels have the same size tires as my summer wheels (225/40 18) even though the wheels are different widths (8 vs 7.5 ).

I'm thinking of transferring my good front tires from my summer wheels to my winter wheels. Then I could just buy two new (summer) tires for my rear winter wheels, and sort the summer wheel issues out at a later date.

Does this sound like a good plan?

Yes - good plan. Usually you want the wider wheels (and tires) for summer tires - most contact patch possible for best handling.

In the winter you want a smaller wheel and tire so that snow does not build up in the fender wells or in case you need to add chains.

[wyovino]

Thanks, Loren.

All set to get the new tires and start using my winter wheels for my summer tires. I like my original wheels, but these are nice too. Not too much of a trade-off. - Bill

[fpb111]

Your original setup sounds like Boxster wheels 7.5" and 9". Also I have never seen "Turbo" look wheels that look like the pic in post #1. The wheels in post #5 look like "Turbo" look wheels.

On the "winter wheels" I would mount a 285/35-18 summer tire on the 11" wide rim. That is the size Porsche recommended when using 10" wide x 18" for my 2003 C2.

I think a 265 is recommended for rims 9" to 10.5" Check the continental specs on tire rack

http://www.tirerack....3&autoModel=911 Carrera Cabriolet&autoModClar=&tab=Specs

Edited March 19, 2012 by fpb111

[wyovino]

Yes, it seems that 265's are recommended for winter tires, but 285's for summer tires on 11J RO 63 wheels.

I looked at the MY2000 brochure and you are correct. The "Turbo-look" wheels are somewhat similar to my winter wheels. My summer wheels are shown in the brochure as "Sport Design" wheels and are pictured on the GT3. I wonder if the dealer did this to "sweeten" the deal, only he used Boxster wheels instead.

I'm going to change the order to 285's. I did some searching and it seems that they shouldn't be a problem.

Update: The tire store says he can't get a 285 in the brand/type tire I need. Since I need to match the fronts, I'm going with the 265's.

Edited March 20, 2012 by wyovino

[fpb111]

What are the date codes on the fronts? If they are older then ~6 years you might want fresh tires on both ends.

[wyovino]

The fronts are only about 4 years old, so I'm good to go until the rears need replacing again. I'll use the hollow spoke wheels for now. When I get around to it, I'll have the Sport Design wheels refinished and either sell them or mount my snow tires on them.

When I got the car back from the tire shop, I loosened and re-torqued all bolts and checked the pressure all around. Standard, or obsessive?

Edited March 23, 2012 by wyovino

[fbgh2o]

On the "winter wheels" I would mount a 285/35-18 summer tire on the 11" wide rim. That is the size Porsche recommended when using 10" wide x 18" for my 2003 C2.

Are you sure about the 35 profile? Most of the 285s that I have seen are 30 profile. That's what I run on my 996.

Edited March 24, 2012 by fbgh2o

[fpb111]

On the "winter wheels" I would mount a 285/35-18 summer tire on the 11" wide rim. That is the size Porsche recommended when using 10" wide x 18" for my 2003 C2.

Are you sure about the 35 profile? Most of the 285s that I have seen are 30 profile. That's what I run on my 996.

285/30 is in my manual also. 35 was brain failure.

Keep me honest Fergus :notworthy:

[Jetskied]

Your wheels are the sport design. It looks like some how you got a boxster set. As far as the 265 size for the rear that will be a real stretch as you have a 11" rear. I think 265 is small on a 10" wheel. I would check to see if the tire you need comes in a 275/35 or if it come in a 295/30 it might be a slight bit taller, but it would fill out the rim better IMO. Your other choice is to get 4 new tires for the turbo wheels or trade in the rear sport design wheels for the 10".