|ProjekTT Roadster: Snow Tire Fitment for Improved Winter Driving
With the onset of winter in most parts of the country, driving in inclement weather conditions, specifically snow, becomes a major reality. Driving in slippery winter environments is an exercise in care regardless of what you drive, though doing so in a car with wider tire fitment or stiffer suspension makes it even more difficult.
Though enthusiasts have been putting larger wheel/tire setups and more rigid suspension componentry on their cars for years, such equipment has recently become much more commonplace. 17-inch wheels and sport suspensions now come equipped from the factory, and though North American cars are still fitted with all-season radials, there is plenty of room for improvement.
Wider tire fitment on a car is not a good thing to have in the snow, especially on lighter automobiles. These wide tires act as skis, riding on top of the snow and thus effecting traction negatively. Even all-wheel-drive and heavy cars are not immune to this "ski effect", which is important to note.
A tighter suspension doesn't help matters in the snow. With less suspension flex, more force is thus transferred to the traction of the car. While this helps rid under steer in the dry, it exacerbates the side effect in the snow, making a car more likely to slide in cornering.
In parts of Northern Europe, where snow is commonplace, cars are required to use dedicated snow tires. Generally, automobiles are sold with summer tires in Europe for improved dry weather performance. During certain months of the year, cars are required by law to be equipped with snow tires.
In the US, we have more lax laws in this regard, and most drivers go along all year on their all-season radials. Worse yet, many who modify their cars put aggressive dry weather tires on their cars with no regard for winter driving; an action that can become particularly dangerous when the flakes start to fall.
ProjekTT has recently been fitted with upgraded alloy wheels and aggressive summer tires in addition to a stiffer suspension (you'll see these updates on the car within weeks), so the need for snow tires became of higher concern to us, even with the relatively mild Washington, DC winters.
Doing Our Homework
In performing our research on what we wanted to fit to the car, we realized that the more affordable Volkswagen 15-inch steel wheel was out of the question due to the TT brake size. However, the New Beetle is fitted with a 16-inch steel wheel that does clear the larger TT componentry.
As it turned out, Tire Rack, an obvious choice for our snow tire needs, does stock a snow tire package for the Audi TT that includes the OEM New Beetle steel wheels, fitted with Dunlop SP® Winter Sport M2 tires in a 205 55 16 size.
Dunlop claims that the SP® Winter Sport M2 offers premium performance in all weather conditions. However, the tire has been designed with adverse conditions specifically in mind. This tire also happens to be factory-recommended by Audi and Volkswagen specifically for use on their cars, in addition to recommendations from Mercedes Benz and BMW. It has even been Porsche-approved for 100% of their current vehicles winter tire fitment.
The SP® Winter Sport M2 is rated for "Severe Snow Conditions" by the Rubber Manufacturer's Association (RMA). Tire Manufacturers in North America, along with the RMA, have established an industry-wide definition for passenger and light truck tires intended for "Severe Snow Conditions". Tires falling into this category must meet a performance based set of criteria that encompass tread pattern and construction elements and materials that generally provide a given level of snow performance.
The new RMA standard is intended to make it easier for consumers to distinguish all-season tires (rated with an M&S Rating), from tires rated specifically for "Severe Snow Conditions". Tires in which this rating applies are marked on the sidewall with a logo that looks like a mountain with a snowflake inside the design.
The RMA warns that tires with this new designation must be mounted only in sets of four (4). The thinking behind this is that a full set is necessary to maintain the handling balance of the vehicle in snow and ice conditions in addition to dry pavement.
Dunlop further warns that a driver should never mix radial snow tires with tires of other construction, size, ply rating, performance rating or pattern type. They also recommend that one should always match the performance ratings of the original tires or follow owner's manual instructions in this regard.
For instance, "T" rated tires may replace "H" rated original equipment tires in sets of four. Dunlop instructs that for winter tires, it is acceptable to use a snow tire rated not more than one step below the OE tire speed rating - or the equivalent speed rating, and fitted only in steps of four.
Use of a full set of four snow tires is specifically recommended by Dunlop for front-wheel-drive vehicles such as our TT Roadster. They go further to say that if high traction snow tires are mounted on the front and lower traction tires are mounted on the rear; the rear of the vehicle can lose traction during cornering or braking on snow or ice and result in the car spinning out. This is a difficult condition for most drivers to control. Use of snow tires at all four corners of the vehicle will provide the most effective and safest winter driving.
These Dunlops' design features a directional tread pattern. A directional tread pattern means that the tire has been designed specifically for rotation in one direction for maximized performance. This means that you or your repair shop will need to use care when mounting the tires to the vehicle. An arrow directing the forward rotation of the wheel is located on the sidewall of the tire and should be followed as you choose what point to mount each tire to on the car. Further, rotation should be limited to front/back swapping only as you will lessen wear, safety and performance levels of the tire should you mount them incorrectly.
Ordering & Delivery
We went ahead and placed our order with the Tire Rack, and our Dunlops mounted and balanced on the Volkswagen 16-inch steel wheels arrived at our door days later. The wheels themselves are painted black and offer a decidedly different look to the car that reminds us of the movie Mad Max.
For obvious reasons, those who make the investment of purchasing snow tires for their vehicle will not use the tires year round. This means that the tires, like our Dunlops on our New Beetle steel wheels, will find themselves in storage for much of the year.
Dunlop was also quite forthcoming in providing us with information about proper storage of tires over a given length of time. They suggest that because tires are highly engineered products composed of a range of materials, they should be stored in an area that offers protection from heat, light, moisture, ozone and deformation during storage.
They further recommend that an individual planning to store a vehicle for an extended period of time should remove the tires from the vehicle, place them in plastic bags, and stack them in a cool, dark place. Tires lose air with time, so leaving them on a vehicle in contact with the ground or other surface for an extended period of time can result in excessive deflection, which can cause flat spots on the tires.
Trained eyes may notice some differences and modifications on the project car that have not yet been covered in the project series. Rest assured, we'll be covering them over the next couple of weeks, however, in the interest of safety and the onset of winter, we chose to move our snow tire feature to an immediate run on the website.
We have not yet had a chance to drive the car in snowy conditions. As of this point, winter on the Eastern Seaboard has been quite calm. However, weather forecasters tell us that we are in for a heavy winter, so we'll post an update to this article as soon as we have had a chance to pilot the vehicle in snowy conditions.