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Recommended Posts

Posted

Hi,

I have a 2005 Cayenne Turbo which came with BBS RXII 10.5 x 21 (part RX519) rims. I need to buy new tyres and wonder what size tyres these rims will take? I know I must use low profile 35's but not sure whether I can I use 295 x 35 ? BBS don't issue a spec (unless it's in german!), tyre sites seem to recommend 275's but the rims I bought came fitted with Dunlop Sport 285's.

Porsche now seem to support 295 x 35 on 10 x 21 rims.

Confused? I am !

Can I use 295 x 35 on a BBS 10.5 x 21 rim is the basic question I guess!

I have searched and can't find the info on the site but any redirection to an existing answer very welcome.

Thanks,

Peter

  • Admin
Posted

Porsche has only approved 21 wheels for MY07 and newer (Gen 2) Cayennes.

For MY07 and newer they approve:

295/35R 21 107Y

Continental Cross C. UHP N0 (Inside/Outside)

Michelin Latitude Sport N0 (Inside/Outside)

Pirelli P ZERO ROSSO N0 (Inside/Outside)

Yokohama Advan Sport N0 (Inside/Outside)

Posted

Hi Loren,

Really appreciate the info.

I am happy that 10.5 x 21 work on the car as they were supplied by Porsche main dealer and drove beautifully for 2 years.

I know that Porsche fit 295 x 35 tyres onto 10 x 21 rims. Would you expect any problem fitting the same tyres to 10.5 x 21 rims?

I have researched but I don't understand how the tyre get's matched to the rim - is it just rim size? How does the rim width (10.5) impact the tyre specification (the 285/295 bit)?

Appreciate your help,

Peter

  • Admin
Posted

It is more likely a question of offset of the wheels and whether the wheels set 0.5 inches further inside (perhaps touching something) or 0.5 inches further outside.

Posted

So can I recap?

1. 295 x 35-21 will fit onto 21 x 10.5 rims but

2. the unknown is whether the extra tyre diameter (offset) causes an obstruction inside (wheel arch cavity) or outside(wheel arch itself)

Is that about right?

Thanks....

Peter

  • 2 weeks later...
Posted
Loren,

Thanks very much for your help. I'll report back if I learn anything useful...

Peter

Hi,

I even have 22"x10" on a Gen1 with Toyo Proxes ST 295/30/22 - some considerations :

-I don't think your wheel arches will be the problem, but watch the ET (einpresstiefe or offset)

-in my turbo there's a tyre size setting for the TPMS to be made; (Summer 275/40/20 is the biggest selectable in the menu), I lost TPMS functionality and I'm guessing the nav computer also uses this to compensate distance errors.

-you're fuel consumption will slightly increase due to higher roll resistance (so slightly less acceleration power & slightly less top speed as well) - I felt the difference from upgrading from 275/40/20 to 295/30/22..

-maybe the most important consideration : my rims always touch the curbs first, the tire wall isn't protecting them anymore...(well depends on your personal situation off course...I'm living in Belgium, Europe where we have tight parking spaces/narrow streets in the cities so curb rash is inevitable in this case; California is a different story I guess..)

-..but it makes your car look **** sweet! (even the 20" looks "small" on the Cayenne)

Have fun!

Gunther.

Posted

Gunther, Loren,

Thanks for your input on this. I had the 295x35 tyres fitted last week onto BBS RXII 21" alloys and it appears that offset and tyre size is no problem.

295 x 35 on the big RXII 21" alloys look great !

I have got one extra spare (brand new) set of the BBS RXII 21" alloys - any idea on a good website / place to sell them in Europe (I am London / Prague)? ebay is too generalised for this type of stuff.

I have 3 sets of alloys, which rather sadly is one more than my wife says I need ;)

Anyway, thanks again for your help,

Peter

Posted
Gunther, Loren,

Thanks for your input on this. I had the 295x35 tyres fitted last week onto BBS RXII 21" alloys and it appears that offset and tyre size is no problem.

295 x 35 on the big RXII 21" alloys look great !

I have got one extra spare (brand new) set of the BBS RXII 21" alloys - any idea on a good website / place to sell them in Europe (I am London / Prague)? ebay is too generalised for this type of stuff.

I have 3 sets of alloys, which rather sadly is one more than my wife says I need ;)

Anyway, thanks again for your help,

Peter

Peter,

I am in Prague and I would be interested in your extra set of alloys. Could I see them?

Cheers

Roman

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