dgjks6

So I am looking for snow tires for my 997.2 Carrera 4.

Porsche says 295/35/18 on the rear. Tire rack says 265/40/18 on the rear.

The TSB I have says 295's are the only acceptable size for the rear, but I heard the 997.1's could run the 265's. Is there a reason for the change?

Bruce In Philly

Hmmm....

Diameter is about the same:

295/35/18 = 26.130
265/40/18 = 26.346

Peace
Bruce in Philly

Dennis C

I'm running 19" winter wheels on my 997 with the 295mm width rear tires recommended by Porsche. On my 996 C4S, I ran 18" wheels with 265mm width rear tires. One thing I can tell you for sure is that the 265mm width tires performed better in snow than the 295s.

I think that 265s would be fine if the wheel/tire combination diameter is close to the 295s. Perhaps somebody with more experience will respond.

shammerman

My manual for 4S states 265 for 18 inch (what I have) and 295 for 19 inch:

Snow tires front 235/40 R 18 91V M+S 8 J x 18 H2 57 mm 58.5 in./1486 mm
rear 265/40 R 18 97V M+S** 10.5 J x 18 H2 60 mm 60.4 in./1534 mm

or front 235/35 R 19 87V M+S 8 J x 19 H2 57 mm 58.5 in./1486 mm
rear 295/30 R 19 100V XL M+S 11 J x 19 H2 67 mm 59.7 in./1516 mm

halo777

I went with GT3 RS diameter sizing for my winters...

245/35/19 FRONT
275/35/19 REAR

I dont have much to compare them to, but they seem to work wonderfully with my 08 C4s (do not trigger any lights on the dash). The bigger size overall gives a little bit extra sidewall for the winter/spring potholes.

And the 245 FRONT/275 REAR combo decreases understeer, keeping the handling quite sporty (and a little bit tail happy).

vern1

265 on 18's. Better in snow, cheaper to run

mpath

Punxsutawney Phil didn't see his shadow this year, so um, isn't it kinda late to install winters?

I'm running 295's on my 06 C4S. It's been a mild winter here except on a weekend road trip through some slush. Seemed to work fine though I'm sure my rear wheel drive BMW on dedicated winter tires would have been fine too.

user 72902

The only reason I could see is if the rim is either too narrow or too wide for a 265 to a 295 tire.

chuck911

Vern is right. The situation with snows, the narrower tread creates more pressure psi to cut through snow, slush and standing water. I took this advice from Tire Rack years ago and you really feel the difference. In addition to handling better, narrower tires also cost less and throw up less crud to chip your paint.

dgjks6

When I was doing the tire size comparison

235/40/18 to 265/40/18 is 3.5% difference
vs
295/35/18 is 2.8%.

I thought that maybe the new transmission with the pdk/awd required a narrower margin and that is why Porsche changed their recommendation

And yes, 1 month for snows is not much. But better than not driving for a month.

Also can use 18's for the winter - and it gives me an excuse to buy 19 inch rims for the summer

JAGMAN1

I have 265's on 18's right now. If I had to do it over I'd use 295/35/18. Let me explain my reasoning. I don't drive in the snow, or really bad weather, or when there is a lot of sand and salt on the road; for those days I take the Cayenne. My 997 is not a daily driver, but I like to be able to drive it any given day if my DD is down for repair.

So, since the bulk of my winter driving is on fair weather or better days, I'd prefer the added grip the 295's would offer on dry/wet pavement. If I were going to be driving in snowy conditions I'd stick with the 265's. I have a C2S.

I have Pirelli Sottozero's on now. Winter tires are mandated here in Stuttgart, and I want to be able to drive in the cold weather, not necessarily in the snow.

4 Track Mind

After riding sottozero 295s on 19s for 6 years, this winter I mounted Blizzak 265s on 18s. The 295s were adequate in all Chicago winter conditions, even when the front spoiler functioned as a plow. On cold dry pavement, they were almost as good as PSSs in summer. Still, I was underwhelmed by the snow grip relative to Blizzak shodden quattros when I played slideways rally driver in snowy parking lots. With the new 265s mounted, I was aware of a loose rear end as soon as I hit the highway. It was a bit unsettling not unlike the light front end someone described on another thread after moving from a front engined cayenne to the 911. I ordered some spacers as soon as I got home hoping to remedy this as well as fill the huge perceived gap lateral to the sidewall. By the time the spacers were mounted, I had grown accustomed to the new handling so I'm not sure how much of a difference they made. Aside from an early blizzard, we've had little snow this year and I would have been better off with the 295s. I don't know where you live, but 295s on sottozeros will be best for cold dry winter driving and still be able to safely get you where you need to go whenever you need to go. If you'd rather drive aggressively in the snow and are fine with dialing it back a bit in the dry, go with Blizzaks on 265s. This set up has not yet tripped any alarms on my 2009 997.2 C4 with SPASM. If you're in the mountains, get chains. Porsche sells them. As an aside, I'm really impressed by the Nokian WRG3s on my Subaru. They're marketed as a "winter bias" all season and would be a good compromise for someone who didn't need the best summer or winter performance and didn't want to bother with changing wheels. Not sure about 911 fitments but all seasons might be too much of a compromise for this car.