Over the course of winters past, I’ve been asked numerous times by acquaintances, friends and family whether a certain vehicle would be a good choice for driving winter roads. I want to cover the topic once and for-all with this post. I will go over what makes a vehicle good for winter driving and then go into detail about what makes winter tires different from all-season or summer tires.
Driving technique, drastically more important than the vehicle you are driving, is something I will cover in a future post.
First, I want to define what I mean by winter driving and winter roads. I’m referring to maintained roads, highways and freeways. This includes getting around town, travelling between cities (potentially over mountain passes) or going to ski hills in winter. This advice does not apply to travelling on unmaintained or remote winter roads where snow depths can become excessive.
Following from that, the road conditions I’m referring to are dry, wet, icy, slushy, compact snow or limited amounts (rough maximum of 12 inches) of fresh snow, all in cold temperatures.
With that context out of the way, let’s get into what makes a good vehicle for winter driving.
The answer is simple: any vehicle is good for winter driving if it has good winter tires.
If you read nothing else in this post, take that answer to heart. Your tires are the only things holding your vehicle to the road, so no other part of your vehicle matters more for winter driving.
Note that I didn’t mention Four Wheel Drive (4WD or 4×4) or All Wheel Drive (AWD). Neither system is a replacement for good tires because they don’t help with braking. Their benefit comes in making the car go forward and, to some extent, keeping it straight on the road.
Because of those benefits, I do recommend a vehicle with 4WD or AWD if you drive in the snow regularly, but they are by no means a requirement.
(Update: I’ve expanded on my thoughts about AWD and winter driving in my next post.)
Other factors I’ve found people regularly associate with a good winter vehicle include vehicle weight, tire size and ground clearance. Let’s run through those.
- Vehicle weight can help somewhat with vehicle stability in snowy conditions, allowing the vehicle to push through the snow rather than be pushed around; however, the benfit isn’t nearly great enough to bias vehicle choice.
- Larger tires only matter in extremely deep snow, a situation which I’m explicitly not covering as mentioned above.
- Ground clearance only matters in extremely deep snow, a situation which I’m explicitly not covering as mentioned above.
So what separates a winter tire from all-season or summer tires? There are a number of factors, but the largest is the tire compound or rubber.
Rubber hardens in colder temperatures. Soft rubber has more grip, exactly what you want in slippery winter conditions. Winter tires use rubber compounds that are significantly softer than other tires so that as temperatures drop, they remain pliable and sticky. Because of this, a winter tire will have significantly more grip than an all-season or summer tire in cold temperatures even on bare, dry roads.
If softer rubber gives so much more grip, why don’t we just use winter tires year-round? Mainly because of longevity and fuel economy. Softer rubber wears significantly faster in hot temperatures and reduces fuel economy due to increased resistance to rolling. Additionally, if the rubber becomes too soft in extreme heat, it can actually have less grip than a harder rubber.
There are a couple of additional benefits to winter tires beyond tire compound:
- Significantly increased siping. When you look at your tires, particularly winter tires, you’ll see what look like cuts across the tread blocks. These cuts are called sipes and increase the number of surfaces gripping the road.
- Strategic packing. Snow-on-snow grip is actually quite high, so winter tires are designed to strategically pack with snow to utilize this benefit.
If you’re going to be driving in the snow this winter, or just live in a city that gets very cold, grab yourself a set of winter tires this year. The cost will be infinitely less than that of your life or someone else’s.