Driving in Snow

I know there are some differing opinions. But since we are back to snow season, I thought I would put out my thoughts. These recommendations are based on my 40 years of driving in snow in everything from very small – 1978 Honda Civic (FWD) – to medium duty truck – 1986(?) Ford F7000 (4X4).

Winter Tires:

If you will be driving in snow a lot, or just want to be as safe as possible, get winter tires. Winter tires can be studded or not studded. Studded tires will be the best on ice, but studs don’t do a lot on softer snow. Winter tires (studded or not) perform much better than all-season tires on snow and ice.

All winter tires will have the “three-peak mountain snowflake” (3PMSF) symbol on them. The “mud and snow” (M&S) rating is not the same. The M&S rating is basically meaningless. The 3PMSF actually means the tire passes a traction test on snow. But it’s a pass-or-fail test. Not all 3PMSF rated tires are equal in the snow. More and more all-season and all-terrain tires have the 3PMSF. These are not bad tires, I have them on 2 of my vehicles, but true winter tires will still outperform them in snowy conditions.

Tire Chains:

For most on-road driving in snow or on ice, tire chains give the ultimate traction. If you will be going over mountain passes, will be in snow in a 2wd vehicle, or don’t want to spend the money for winter tires because you may not even see snow this winter, then get tire chains. My recommendation for most people would be the “diamond” type chains. They are a good compromise on price, traction, and durability. Cable chains are a lot better than nothing, but aren’t great for compact snow and ice. For heavy-duty applications (heavy loads, towing, etc), get the old fashioned ladder style chains. They are probably the most durable (although the lightest ones won’t be).

I’ll make a little plug here (no association) for Les Schwab. If you are not sure you will use the chains,  they advertise that you can return unused chains in the spring. But, if you plan to use them, you can probably find chains cheaper elsewhere.

Tire Pressure:

If you are driving on plowed roads, I recommend that you run at your normal tire pressure. Keeping the tire pressure high gives the tires the best chance of cutting through the snow and reaching the ground underneath.

If you want to drive in deep snow (snow wheeling) lowering the tire pressure may be a good idea. My definition of deep snow depends on the ground clearance of your vehicle – if the bottom of your vehicle is dragging significantly, then it is deep snow. Whether lowering the tire pressure is a good idea depends on the type of snow.

Lowering the tire pressure helps if you want to drive on top of the snow. This is only possible in fairly dense, wet snow. If the snow makes decent snow balls, it indicates you might be able to drive on top of it. If you are going to lower your tire pressure you must have a pump to reinflate your tires before driving at speed again.

If you are going to try and drive on top of the snow, you are very likely to get stuck at some point. At a minimum carry a good shovel. I also recommend traction boards, a jack (high-lift if your vehicle has appropriate jack points), a big board to put under the jack, and a kinetic rope/strap and a friend with another vehicle. It’s always fun to have two vehicles stuck instead of one. 🙂

Lowering your tire pressure generally doesn’t do too much until you get to 15 psi or lower (this varies a lot with snow condition). Most tires can be lowered to 10 psi without any problems in snow. My go-to pressure is 5 psi, but I don’t recommend you go this low unless you have oversize tires.

When trying to drive on top of deep snow, I generally recommend against using chains. They do increase traction, but can dig a hole very fast. If a wheel starts to spin with chains, it requires lightning fast reactions to stop the tire before it digs a deep hole and leaves you stuck. Under some conditions, chains will help you get further, but generally with an increased risk of sinking your tires in deep holes. Also, if you use chains with low tire pressure, you run the risk of damaging your tires’ sidewalls.

Note that If you are in fluffy, powdery snow (common when the snow falls at colder temperatures), then you probably can’t drive on top of the snow. Under these conditions, lowering the tire pressure probably won’t help.