Boxster S fitment and winter tires - 986 Forum - The Community for Porsche Boxster & Cayman Owners

clueless1 · 10-26-2010, 09:14 PM

I've been searching and googling all the old fitment threads and I am still at a bit of a loss as to tire fitment.

I currently have OEM 18" wheels on the car. The rims are pretty shot and I was planning on replacing them. Because I am way up north I will need winter snow tires. I know that 17" are supposed to be better as winter tires, but in order to save some dough I was thinking I would use the 18" rims I have currently and buy 19" rims for the summer. I haven't been able to figure out how dramatic a difference I will note in a boxster using 18" good winter tires (vs. 17")????. I will be doing short haul city driving primarily.

I have having a difficult time finding tires I want in the OEM reccommended sizes (225/40/r18 and 265/35/r18). I was looking at nokian hakkapelita 7s (studded), but they only appear to be available in 225/40 & 255/35. Alternatively, I know someone up here who has LM25s that are a few years old (but barely used, <1k on them) that are 235/40 & 265/35.

Will there be any issues with fit if I went with either of these alternatives? What about tramlining? Anything else I need to know if deviating from mfr recc'd size?

litteng · 10-27-2010, 08:15 AM

so what does CA mean in your location? kalifornia or canada?

helps if you fill out your info a bit more. from checking some of your previous threads i found you mentioned edmonton, therefore i take ca to be canada.

my boxster is not yet winter ready but its not going out in the crap that landed on us yesterday,

if you need to drive it i would get 17"s winter rims and tires if the fit over the brakes, and use the 18's for summer in canada. 19's are a waste of money because the roads are so poor, but you should know that already

you say the 18's are shot. in what way are they shot, edges gouged? or no longer shiny

ad more info to your bio, and it makes it easier to get together. i am running up to edmonton for remembrance day....

Mark_T · 10-27-2010, 08:27 AM

Got dumped on, did ya? Hope it's not headed this way...

clueless1 · 10-27-2010, 10:08 AM

Edmonton ... where winter has already arrived. Regrettably.

one of the problems is though you are right, 19s look so much nicer. even if i went with 18s in the summer, i would need new rims. my 18s now are not shiny, bubbling/peeling. generally not looking good, detracting from the rest of the car.

i was thinking 18" hakk 7's might be better than 17" non-studded. i can't find the hakks in 17" with the right aspect ratio. Even in the 18" I would have to move down to a 255 rather than a 265 if I wanted hakk 7s. Even that will cost me twice as much as non-studded LM25s -- and the best 18" non-studded I have a line on are the 235 fronts. Hard for me to imagine 10mm plus or minus would make that much of a difference, and I see lots of posts with guys running alternative sizes, but I don't have any definitive info regarding what is possible with a boxster re plus or minus sizing. Interestingly, since its wheel width that should matter for winter tires, I have been surprised at the focus on smaller wheels rather than minus sizing, which to this uninformed reader seems like it would be more important?

I have not been able to find a lot of selection at either the 18" or the 17" OEM sizes. Plus I don't wanna spend a bunch of money unnecessarily, and $700 give or take for a set of 17" rims .... I dunno. Also, since I'll be doing mainly city driving it will be mainly slush and ice i'm dealing with.

gschotland · 10-27-2010, 11:02 AM

I'd go with 17s for winter tires. Better ride, more (& less expensive) tire choices, and less chances of crashing a rim. I don't think 18s will gain you anything meaningful in terms of grip.

For my winter tires I picked up a used set of 993 Cup II(?) wheels for $250. Winter quality (a little scratched) used 17" Boxster wheels shouldn't be too hard to find in your area for a similar price.

Another alternative you might want to consider is a wheel & tire package from a place like TireRack. When you add mounting and balancing cost to used wheels, the package with "good" quality aftermarket wheels may not be much more.

clueless1 · 10-27-2010, 11:55 AM

Right now the ONLY tire listed at tirerack in 17" is the Pirelli 240.

If I could find beat up 17" rims for $250 I'd buy the RIMS in a heartbeat. Not too sure about the 240s.

brian325is · 10-27-2010, 12:12 PM

I find many used tires and rims by using kijiji. You can break it down by city. Look up auto parts and put in Porsche for search.

Here is an example in Edmonton

http://edmonton.kijiji.ca/c-cars-vehicles-auto-parts-tires-tires-rims-17-Rims-and-Tires-Porsche-Boxster-W0QQAdIdZ233860332

JTP · 10-27-2010, 12:23 PM

Tire Rack has Blizzaks, Dunlops, ans Pirelli winter tires in the OEM 18" size.
http://www.tirerack.com/tires/TireSearchResults.jsp?tireIndex=2&autoMake=Porsche&autoYear=2000&autoModel=Boxster+S&autoModClar=&frontWidth=225/&frontRatio=40&frontDiameter=18&frontSortCode=53650&rearWidth=265/&rearRatio=35&rearDiameter=18&rearSortCode=54300&tab=All

I used Blizzaks in the Alaska interior and they are awesome tires. Performed better than alot of studded tires.

ekam · 10-27-2010, 04:09 PM

You want narrower tires in winter so 18"s are no help.

Buy a set of 17"s now, sell your 18"s and buy a set of 19"s in the spring/summer.

husker boxster · 10-28-2010, 04:26 PM

I have a set of 18" Blizzaks that work great in snow and ice. Use your current set of 18" wheels and get a good set of winter tires. You'll be fine. If you buy 17's, you'll sell your 18's (who needs 3 sets of wheels?) to someone who'll use them for their snows.

clueless1 · 10-30-2010, 10:08 AM

There are a lot of folks who say the same thing. But I'm still completely in the dark re the questions I initially posted about fitment????

JTP · 10-30-2010, 02:50 PM

Quote:

Originally Posted by clueless1

There are a lot of folks who say the same thing. But I'm still completely in the dark re the questions I initially posted about fitment????

I don't know about tramlining or other fitment issues but if you went with 235 up front it shouldn't be an issue as far as fitment. I had 245/40/18 up front with no problems but I would not use that size for winter. I responded with a link to OEM 18" winter tire sizes in an earlier thread, in response to where you said you could not find winter tires in OEM 18" sizes.

Topless · 10-30-2010, 03:38 PM

Surely all you Canucks up in the great white north know that skinny snow tires work WAY better than wide tires on snow and ice. I'm just an old ski bum from California but we learned that lesson back in the 70s. Find a set of 17s and go 205 Front and 225 rear. The money you save in tire expense will probably pay for a decent set of 17 takeoff rims. If you fill, sand and paint your old 18 rims you can sell them tomorrow for $400 cause they will look like new.

clueless1 · 10-31-2010, 06:12 PM

Quote:

Originally Posted by Topless

Surely all you Canucks up in the great white north know that skinny snow tires work WAY better than wide tires on snow and ice. I'm just an old ski bum from California but we learned that lesson back in the 70s. Find a set of 17s and go 205 Front and 225 rear. The money you save in tire expense will probably pay for a decent set of 17 takeoff rims. If you fill, sand and paint your old 18 rims you can sell them tomorrow for $400 cause they will look like new.

thanks topless, i appreciate the post ... mainly because i came to the same conclusion myself yesterday while trying to figure out sensible minus sizing on my own ... and I was wondering if i was nuts or had stumbled across a correct solution. And sure enough, yup, the money i save on tires will pay for rims, if i can find a cheap set which seems to be harder than i anticipated.

I still have a few questions remaining.

If i run 225/45/r17 in the rear with factory fronts, am i correct i will push the car toward neutral but not into oversteer? Anything I think to think about re inflation pressures?

I am thinking 7.5s would be optimal for a 225 (and i think should fit a 205 ok) ... any thoughts about cayenne wheels (17x7.5 et53) all around? I know they are heavy (27 lbs/wheel) ... would this be good or bad. Aren't most of the stock boxster 17 rears 9 inch?

Re winter tires, are things like speed ratings, N ratings, etc relevant ... or does it make sense to just buy the best winter tire (which is what I am strongly leaning toward)? If anyone has a comment about studded/non-studded for edmonton, ab I'm all ears too.

Topless · 11-01-2010, 06:32 AM

Ok, Blizzaks will fit any stock 17" Boxster rim from 7-8.5":
http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Blizzak+LM-60&partnum=245HR7LM60&vehicleSearch=false&fromCompare1=yes

The rims should be easy to find. Any stock 986 Boxster 17" wheel set will work since they are 7 & 8.5". Use only a Boxster rim because they will have the proper offset. There are probably 50 sets of spare 17X7s in Texas because all the Boxster Spec race cars there run 8.5s all around. You would be doing them a favor by helping to clean out their garage of 7" rims. Tire Rack or Wheel Enhancement may also have some decent 7" aftermarket rims for a reasonable price that would work fine. If you order them today you could have them mounted on your car by Friday.