I bought winter tires from Canadian Tire and had them install them. When I got the bill there was a charge of $7.95 per tire for a new valve stems. My vehicle is a 2008 Grand Caravan with about 10 000 km on it. I asked about the valve stems and they said on the tire course they took, some guy said vehicles with tire pressure monitoring systems should have the valve stems replaced every time the tires are mounted on the rims. I called the service manager at my local dodge dealership and he told me that is absolutely false. Another reason why no Canadian Tire mechanic should ever touch your vehicle!! read full review »