When to put on winter tires

The 7 degree rule

The switch to winter tires is about temperature more than snow. Below roughly 7 degrees Celsius, the rubber in all season and summer tires starts to harden. A hard tire grips less, takes longer to stop and slides sooner in a turn, even on bare, dry pavement.

Winter tires use a softer compound that stays flexible well below freezing, plus a tread with deeper grooves and many small cuts called sipes that bite into snow and slush. Look for the mountain and snowflake symbol on the sidewall. That symbol means the tire passed a standard snow traction test. A plain M+S marking alone does not.

So the rule is simple. When daytime highs in Ottawa, Ontario settle around 7 degrees or lower and mornings are near freezing, the winters should go on.

When that happens in Ottawa

In a typical year that is late October into early November. The first snow that stays on the ground usually comes in November, sometimes earlier. The first slippery morning is often before that, when a clear night leaves frost on the bridges and the ramps onto the 417.

Waiting for the first snow has two costs. You drive on the wrong tire for the weeks before it, when the mornings are already cold. And the day after the first snowfall, every shop in the city is booked solid with people who had the same plan.

Book before the rush

The busiest stretch for tire swaps is the week or two after the first real snow. Phones ring all day, booking slots disappear, and people end up driving on summer tires for another week while they wait.

You can avoid that by booking in October. Choose a slot that works, drop the car off or wait for it, and be done before the forecast changes. Online booking stays open at any hour, so you can grab a time the evening you think of it instead of waiting for the shop to open. Saturday mornings are an option too, from 9:30am to 2pm.

On rims or off rims

There are two kinds of swap, and the price depends on which one you need.

• Tires on rims. Your winters are already mounted on their own wheels. The summer wheels come off, the winter wheels go on and the nuts are torqued. This is $50.
• Tires off rims. You have one set of wheels and two sets of tires, so each season the tires are taken off the rims and the other set mounted and balanced. This is $100.

If you are buying a new set of winters this year, a second set of rims is worth thinking about. Each swap after that is quicker and cheaper, and the tires are not pulled on and off the rims twice a year. Steel winter wheels also take the salt and potholes so your nicer summer wheels do not have to.

Full details are on the tire change and swap page.

Check your winters before they go on

Pull the winter set out of the garage a week before the appointment and look them over.

• Tread depth. Winter tires lose a lot of their snow grip as the tread wears down, well before they hit the legal limit. If the grooves look shallow, measure them or ask us to.
• Age. Rubber hardens with age even on tires that look fine. Check the date code on the sidewall, the last four digits of the DOT number, which show the week and year they were made.
• Damage. Look for cuts, bulges and nails. A nail in the tread can often be patched for $20 with a flat tire repair, but a bulge or a sidewall cut means the tire is done.
• Matching. Four winter tires, not two. Two on the front and all seasons on the back makes the rear of the car slide out first on ice.

The Ontario insurance discount

Ontario insurers are required to offer a discount to drivers who put winter tires on their cars. How much it is, and what the insurer wants from you, varies by company. Some want the tires on between set dates, and some want proof of purchase or installation.

Call your insurer before the season and ask. Keep the invoice from your swap, since it shows the date the winters went on.

Across the river

Quebec requires winter tires on Quebec registered vehicles from December 1 to March 15. Ontario has no such law, so an Ontario car can cross into Gatineau on all seasons. Given how many Ottawa drivers commute across the bridges in January, that is not much of an argument for skipping them.

A good time for a look underneath

The car is already up on a hoist for the swap, so fall is the natural time to look at the rest of what winter will test. If the brakes have been grinding or the car has been pulling, say so in the booking. Fall is also the window for rustproofing before the salt trucks come out.

We are at Unit 1, 1541 Star Top Road, just off Highway 417 Exit 112 at Innes Road. Book your swap online, pick on rims or off rims, and add any concerns in the description.