An Audi Q7 with Audi's quattro® all-wheel drive should have zero problems in the snow, right? Not if your Q7 came with 21" Original Equipment wheels and 295/35R21 summer tires. Unfortunately, none of the major tire manufacturers make an all-season in this size and there's not a good alternative 21" tire.
If you live in an area outside the Snowbelt, you may not need a set of dedicated winter / snow tires. However, the summer tires currently on your vehicle aren't going to be much help once the temperature begins to drop. The solution? Downsize to 275/45ZR20 Continental ExtremeContact DWS tires on 20" Andros Spec P wheels.
The ExtremeContact DWS features Tuned Performance Indicators -- visible letters molded into the second rib from the outboard shoulder to alert drivers of their tire's performance levels. A visible "DWS" indicates the tire has sufficient tread depth for dry conditions, as well as wet roads and light snow. After the "S" has worn away, the remaining "DW" indicates the tire has sufficient tread depth for dry and wet roads only. After the "W" and "S" have worn away, the remaining "D" indicates the tire has proper tread depth for dry conditions only.
275/45R20 has the same overall diameter as the 295/35R21 and is 1/2" narrower. The 275/45R20 is an Original Equipment size that Audi uses on certain Q7 trim levels and is compatible. Since your Q7 uses the Indirect ABS-based TPMS system, there are no direct TPMS sensors to purchase. We'll include our free mount and balance, therefore your Tire & Wheel Package ($1156* plus shipping) will arrive ready to install.
*Prices subject to change
In the Scion family, the FR-S gets the most buzz, the xB evokes the most polarizing opinions, the iQ draws the most attention and the tC typically sells the best. The Scion xD gets overlooked as it provides practicality, dependability and efficiency, while simply getting the job done.

If you drive an xD, I'm sure you've been happy with its reliability, efficiency and ease of maintenance. The only area where things get a little tough is in choosing replacement tires. Scion has equipped the xD with the rare 195/60-16 size as Original Equipment. There are only six options available, with two of them being winter / snow tires. This severely limits your chances of finding the tire you may be looking for.
No worries, you can run the 205/55R16 alternate size instead. It fits on your original wheels, doesn't rub on the wheel wells, has a comparable overall diameter and won't affect overall performance. In the 205/55R16 size, you'll find 166 choices to choose from.
Search by size and find the best tire for how and where you drive your xD.
Recently, the following question was posted on one of the BMW forums I moderate: "It's getting close to spring time, and I am just wondering when everyone puts their summer wheels/tires on? I live in Ohio, so I was thinking of putting mine on during the first week of April. Any thoughts? In Cleveland, you never know when the winter will permanently end.
Yes, it's difficult to believe the calendar says another winter season has ended, but that doesn't mean your winter tires have been removed. I'm often asked when is the best time to swap winter / snow tires out for all-season or summer tires? My advice is to wait until the threat of snow is gone. Many are tempted to take off their winter tires early because of an unseasonably warm weekend. However, it's important to remember why you purchased your snow tires in the first place: safety! Is it really worth taking the chance of getting caught in a late-season snowstorm just to have your "fun" tires on a week or two sooner?

If you own a set of all-season tires, you should make the change when low temperatures are consistently above freezing each night and the longer term forecast is showing the same. Getting caught in an early spring dusting shouldn't be an issue as all-season tires can still provide traction in light snow.
Summer performance tires are at their best when it's warmer, as they provide almost no traction in snow. If your area tends to have such unpredictable late freezes, put off the changeover a little longer than you would with all-seasons.
When the time does come, why not do the job yourself? Read "Do You Have the Three Tools Needed to Remove Your Wheels and Tires?" to see how easy it is to replace your winter tires with your non-winter set.