911 Rod

Will 225/40/18, / 265/35/18 work on a 996 Turbo?
They are snows from a regular 996. I know they fit I'm just concerned about the height being the same front to rear.
Thanks
Rod

993GT

will need spacers but otherwise should fit no problem, tire sizes are good
pics of car..

911 Rod

Spacers would make it look nicer, but do I have to have them? Longer studs too?
Getting car next week, but I don't want to jinx it as I've been having bad luck buying cars for a while.

993GT

really need to get spacers, MIGHT be able to 'fit' without but will be almost an inch further in than stock...spacers + new longer wheel bolts(many sources including Porsche directly) and you're good to go!
Good luck with your purchase!!

King_James

Are you asking about wheels or tires? If it's wheels and tires from a regular 996 then they may look funny but should otherwise fit without spacers. If it's tires only (snows) that you're going to fit to your stock 996TT wheels, I believe that's the correct sizing.

993GT

front wheels share almost identical specs, the rears will be about 15mm further in than normal, Porsche # 99636161700 for a 17mm spacer...Porsche # for cars with 5mm spacer is 99736198007, might consider going aftermarket for this to get a longer bolt...
265 is too small for the factory 11" rear wheel, can be done but is a compromised fit...go 10" wheel
Cheers,

911 Rod

It's rims (urbo twists) and tires from a 996.
Do these cars have studs or bolts? My 86 911 has studs and they would be a PITA to change if the spacer wasn't thicker than the length of the stud sticking out.

993GT

Starting with the '97 Boxster, Porsche has used wheel bolts, all track guys(me included) miss the old air-cooled studs but the bolts are definitely easier if you want to add spacers or refresh the hardware...

911 Rod

Can you tell I'm new to this modern stuff! Lol
Are suggesting spacers are for looks or handling?
I think the car would be better in the snow if the rears were inline with the front. No?

993GT

always better to ask than do something wrong
spacers are for both looks/handling, but probably not a big issue anyhow
front and rear axles are already in line so no difference there

adam_

So diameter wise those are a good match. I looked at continntla all seasons and the revs per mile are 828 and 824, front and rear. Almost perfect, within 0.5%.

The rear tires, however, may be stretched - the maximum rim width for a conti extreme contact DWS in a 265/35-18 is 10.5" (range is 9-10.5) I NEVER recommend going past what a mfg recommends...you get a range, you live in the range. IMO Not sure what snows you are getting, but look up the specs on tirerack. I seem to recall turbo twists are 8.5 and 11??? not sure.

A

911 Rod

The height for these sizes is 25.1" for the front and 25.3" for the rear.
That works out to about .008% difference. Is that within specs?
It doesn't sound like much, but the rears will go around 7 times less in one mile.

996tnz

I believe Porsche specced the rears on the 996T to be slightly smaller than the fronts so that they would turn faster and always seem to be 'slipping' a little - apparently to help ensure that some torque was always being thrown to the front (5%). Presumably this pre-loads the viscous front diff to have it warmed up and ready for action.

The difference in diameters you quote actually comes out to 0.8% difference and it would be better if it was 0.8% the other way around (bigger fronts than rears) but still probably fine for daily driving etc. If you are tracking/autocrossing/hooning it and frequently spinning up the rears then I'd think you might only notice a very slight delay and a bit more ****** when the AWD throws torque forwards.

If stretched out on 11 inch rims, I suspect the 265 rears would be smaller than 25.3 anyway so you should be fine.

I recently had to throw some spare worn 265s (on 10 inch ET65s) on the back of mine for a few weeks while awaiting a new set of tires and they ran fine, though the back end was noticeable livelier - 20 odd percent more torque (thanks UMW) and 10 % less width will do that. Car looked horrible with no spacers and mismatched wheel colors but it was fun for a while.

sanyata

Turbo twist are 8.0" & 11"........ GT2 twists are 8.5" & 12".

911 Rod

The car this is coming from is a regular 996, not a Turbo.
Do these sizes still apply?