225's before on the front, now 245's for the snow?

[jbripps]

Hi all,

I know this may be partly OT, but this is a general tire question, and this is the best place to find my answer. My buddy just got snow tires put on his new G35 coupe (great car by the way). The stock sizes are like the 911, different in front and rear. Stock sizes are 225/45's on the front and 245/45's on the rear.

My question is this.....he just had a shop put snow tires on, and they put 245's all around. He's using the same wheels, and I was wondering if this would be unsafe for the front? He said the shop looked only at his rear wheel when they ordered the tires. I advised him to swap the front for the correct sizes. Any disadvantages from this? Any input would be greatly appreciated.

thanks so much,

[johnsjmc]

Does the owner's manual list alternate tire sizes or give snow tire advise? My 911SC book suggests narrow 165SR15 or 185/70SR15 with all 4 the same instead of the 185/70 and 215/60 combination normal in the summer .Does the G35 have a similar unequal weight bias front to rear as a911? I know from experience with deep snow here in Canada (but not driving the 911 in it) that a narrow tire with a deep tread like a Blizzak is better than a wide tire because it will cut down through the snow to the road below .The wide tires tend to ride on top like a toboggan.The 245 low profile tires seem too wide for snow to me more than the same size all round would worry me

[Formerly Steve Wilkinson]

Like he sez, you want narrow tires, not toboggans. There's this silly belief, and it's held by some otherwise-intelligent people, that "snow tires" should be big fat things that plane along on top of the snow. Check out any Scandihoovian winter rally car and you'll see how dumb _that_ is.

Stephan

[dotorg]

Stephen: depends on tire compound. Some are designed to cut through snow, others are designed to hold a coating of snow to the tire, for snow grip.

Having driven both types extensively, under most conditions I greatly prefer the wider tires. They handle more predictably, and only tend to have problems in moderate snow on top of sheer ice, where the tire can actually pull all the snow up with them.

[cegerer]

Here's what the rally guys use:

[jbripps]

Hey,

thanks so much for the responses. I guess my main question is whether having a bigger tire on the fronts poses any safety risk? Are they too big?

thanks,

[toolman]

Wider tires will give you more of a chance to "hydroplane" on top of the snow and slush as "cookie cutters" (narrow) will exert more pressure per sq. inch and get you down to the road better.

[Bill Verburg]

I agree w/ the narrower tire school of thought for snows. On my S4 I replaced the stock summer 225/45x17 w/ 205/50x17 snows.

[jmohn]

There are a lot of variables here (snow is not just snow ), depending on temperature, depth of snow, plowed or non-plowed roads, amount of traffic, etc. Generally, the optimum is narrow tires with aggressive tread on snow\slush. Wide tires are fun in the summer only. The wider "snow composition" tires only work well (IMHO) if there is a constant, even "cushion" of snow under the tire, they fail the test miserably in mixed snow/ice/slush conditions. Your buddy will be at a "distinct disadvantage", in most snowy road, winter conditions, with wide tires on the front. (BTW, I'm a native Minnesotan. We, generally, get some snow in the winter.)

Jerry M
'78 SC