Jump to content

Server Lease Renewal/Software Licenses

Our yearly server lease, software licenses, as well as hardware operating costs, WERE due Dec 4th, 2022. Our current donations have fallen far short of the funds we need to renew. Please remember the RennTech.org community is Member supported so please consider a donation to help...  THANK YOU!

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

will a 285/35R18 fit in the rear? with ROW 030?

Recommended Posts

i am looking into a new set of rear tires and the tire guy asked if i could fit a 285/35R18 in the rear so to increase my options....

i currently have the 285/30R18 P-Zeros on there.

will this tire fit with the ROW 030?,




Link to comment
Share on other sites

  • Admin

Well, I'm not sure what you are after, here are the measurement differences:


Sidewall: 3.4 in

Radius: 12.4 in

Diameter: 24.7 in

Circumference: 77.7 in

Revolutions/Mile: 815.0


Sidewall: 3.9 in

Radius: 12.9 in

Diameter: 25.9 in

Circumfrence: 81.2 in

Revolutions/Mile: 780.0

Besides the tire being 0.5 inches taller in the sidewall and 1.2 in overall diameter you speedometer error will increase (revs/mile) by 4.5%. So your speedometer would be slow (i.e. speedo reads 60 MPH you are actually traveling 62.7).

Perhaps Viken can add some comments?

Link to comment
Share on other sites

well with that much difference, i think i'll try to stay with a 30 series... i was just looking for more tire options, the slightly fuller wheelwell would have been ok too, however it seems to throw everything else pretty far out of whack....

thanks Loren

out of curiosity, do you think there would be any rubbing issues with a 35 series?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.