dcdude

Nice to see those being used, too. Here in Chevy Tahoe land, they're mostly used by single mommy drivers for on-road adventures over to the mall.

You're an ambassador for the "classic Porsh" movement, Ken! Kids probably can't even drive a manual trans. I heard that has reached epidemic proportion among this generation, even among the jr. "car guy" wannabes. I guess we can thank SUVs for that as well.

vaujot

Cool pics, Ken.
I have been wondering about the difference in circumference of the tires, especially, since you run on a AWD car and need to stay within certain parameters in order to avoid stress on the middle differential.
Here's what I found via a calculator for tire circumference:
205/50x17 = 193.6 cm circumference
235/45x17 = 195.6 cm circumference (1% more than 205/50)
for comparison:
225/45x17 = 192.8 cm circumference (0.4% less than 205/50)
255/40x17 = 193.3 cm circumference (0.2% less)
As a result, you have 1% more circumference on the rear wheels than on the front. I can't tell you if that is a problem for the AWD-system or the ABS. Maybe someone here can chime in?

Since someone asked about 16 inch wheels, I use 1 -inch cup 1 narrowspoke in the sizes 7 ET 55 on the front and 8 ET 52 on the rear with the tire sizes recommended by Porsche (205/55 and 225/50). Works well. 16 inch wheels should fit your car, unless you have bigger brakes (i.e. from a turbo, C4s or similar).

Wilder

Awesome Ken. I used to run my C4S with Blizzaks and would purposely take it out to play in the snow. People looked confused whenever they pulled up to the car. I've had a number of SUVs and none handled as well as the C4S in the snow with proper tires.

race911

There's no center diff on a 993. I'm not even sure you call the 964 setup center diff equipped, but someone who's been in one of those G50s can correct me.

My car is a C4S with the factory supplied brakes, no way 16" wheels work.

When I used to extensively track my '92 964 C4 from '98-'01 (30+ events), I ran all manner of supposedly out of spec tires fiddling around with what worked. Never had a diff or ABS issue. Anyway, isn't the +/- 3%?

My feeling from not really using the above-mentioned 964 C4 in foul weather is that the 993 is just as good. Very limited experience though. What I do think is that the super-AWD of the 964 is better for getting "unstuck." Both Friday and Saturday afternoon the clutch was the weak link in getting out of the parking spot--release clutch, apply throttle, engine revs but no car movement. Now I'm not talking about a 4K rev up here with the clutch burning up. Subtle, and something for me to be careful with as the car currently exists with ~60K on the clutch. Next purchase is going to be a collapsible snow shovel to make pulling out easier. Something tells me I've seen the worst two days I'll be driving the car of the whole winter.

syzygy

Ken, can you explain what you mean by super-AWD with the 964?

As well, did I read that correctly that you had your clutch released/engaged and in gear but with no vehicle movement? That doesn't sound good. Maybe I'm just missing something, here, but that seems a bit not right...

race911

Ack! Someone help me out here. 993 is merely a viscous coupler, 10-40something% power to the front based on slippage sensed. Right? 964 is mechanical 30+% front, with the PDAS having longitudal and lateral sensors plus the ABS sensors figuring out what more needs to go up front. It's domesticated 959. Nice to get you un-stuck, or up an icy slope, but at ~20 years old now just be thankful an installed system is still working. Which they tend to do, until they don't.

Yes, you read right that the clutch was released and the car didn't move. It's not good, by any stretch. But what are you going to do? Caught me off guard, and I think a less sensitive owner could have done some permanent damage. I don't think I'm in any worse shape than if I had sidestepped the clutch on a hard launch (ala magazine testing). Just something to let the group know about. Conventional wisdom would suggest that one, or more, wheels would spin. Maybe that would be so if the summer tires were still installed?

curve lover

GMC trying to get to the mall

Edgy01

Ken--you got it right. The 993's viscous coupler is a much simpler AWD system that was adopted after Porsche found that the 964 (Carrera 4) was just too complex. They had as their prototype the 959 but as we all know you don't want to really have to maintain one of those if you aren't loaded to the hilt.

The viscous coupler remained on the Porsche scene for a very long time. It wasn't until the 997 Turbos and then the MY09 Carrera 4 did they return to the more sophisticated electronic differential. (Apparently reliabiliy targets were finally met).

What is most reassuring is how incredibly well even the RWD Carreras perform with true snow tires (not the compromise M+S tire). The rear engine weight over the driven wheels was Germany's solution to winter mobility for the masses for a very long time. I have yet to get stuck with my RWD VW Vanagon (also available in the Synchro model with the similar viscous coupler) when equipped with four proper snow tires (like the Michelin Alpin) but still carry chains in the event the going gets rougher. Sadly, the more modern Porsches (e.g., 997) have some chain clearance issues which complicate winter driving contingencies. For example, my PCCB equipped car needs to have 18 inch rims (with snows) fitted in order to both clear the brakes and the fenders if you have to strap on chains. The stock 19s are just too close to clear the fenders. Fortunately, the maturing ABS and active suspension systems make the impact of a significant rear bias less problematic in more complex road conditions.

vaujot

I don't think that's a new issue. If I am not mistaken, you can only use chains on a 993 when running 8X16 wheels with a 70mm offset an 225/50 tires. At least that's what I think the official List of wheel and tire combinations from Porsche says. In any case, I am sure that the use of chains is limited to the smaller, narrower rear-wheel setups.

race911

Official recommendation in the manual is for 8X17 w/ 225/45-17 (and 30mm spacer) for the widebodies, which allows chains.

Bigger picture here is that Caltrans will NEVER have a 4WD/AWD + chains control (aka R3). They'll close the road first. So as good as a RWD 911 + real snow tires might be, you run the risk of getting stopped. I got a funny look the first day rolling through, but the guy didn't stop me. The next day, I think it was the same guy, and he recognized the car. Not like there's more that one 911 of any generation running around up there..........

Tried to get some fun snow pics the past couple of days, but it's pretty much all plowed to the side. Then there's the other pesky detail that my photographer (Karen) screwed up her knee pretty severely yesterday, and might be done for the season. I'm killing time at the ER right now, waiting to see how serious it is.

fast_freddy

I'd drive my 993 in the winter if the salt around here didn't destroy it. It's the best car I have ever driven in the snow bar none. As a point of reference I have had all manner of AWD cars (Audi's, MBenz, Subaru) and they don't even come close to a 911 on snows.

77'3.6vram

You need to buy four 16 in spare tires.The spare is 5 and half by 16.Put 205/60/16's all around.You will need 30mm spacers on all .In CT we can run studed tires from Oct.15 to Feb.15.I run my C2 with LSD in the most extreme snow conditions.It's a blast.

keithgreer

Great story and photos, thank you for posting. I am a skier who lives in Southern California, and head up to Mammoth quite a few times each winter. I picked up a 1997 4S this summer and I have been wondering how they do in snow. Thank you for the first hand account.