A guide to Auto$mart vehicle maintenance: Tires and wheel alignment
Here's where the rubber meets the road! Rolling resistance is a key factor that affects a vehicle's fuel efficiency, and the best way to reduce rolling resistance is to maintain correct tire pressure. Operating a vehicle with just one tire under-inflated by 8 psi (56 kPa) can reduce the life of the tire by 15 000 kilometres and increase the vehicle's fuel consumption by 4 percent.
You might find resistance in your tires if you don't maintain them. Rolling resistance results in premature tread wear when your tires are under-inflated, increasing fuel consumption. Measure tire pressure (when tires are cold) at least once a month and on days when the temperature has dropped significantly. Also check your tires for uneven wear, which could be a sign of over-inflation, under-inflation or improper wheel alignment.
Under-inflated tires are estimated to cost Canadian light-duty vehicle owners almost 643 million litres of fuel annually. At $0.79 per litre for regular unleaded gasoline, that amounts to more than $500 million a year in wasted fuel.
Rotating your tires helps prolong their life and improve fuel economy. On most vehicles, they should be rotated every 10 000 kilometres, or about twice a year. Consult your owner's manual for the recommended rotation pattern and frequency for your vehicle.
Tire pressure needs special attention in cold weather. It can be expected to drop by about 1 psi (7 kPa) for every 5°C drop in temperature. Tires also lose a certain amount of pressure due to their permeability – by some estimates, as much as 2 psi (14 kPa) per month.
Regular tire inspections are therefore crucial to improving your vehicle's fuel economy and reducing emissions. This inspection should include the following:
- Measure tire pressure at least once a month when the tires are cold. The vehicle manufacturer's recommended pressure for the front and rear tires is specified on a plate or sticker attached to the edge of the driver's door, the door post, the glove compartment or the fuel tank door (the pressure marked on the tire itself is the maximum pressure and is not likely to be the same as the manufacturer's recommended pressure). If you can't find the plate, check the owner's manual or consult your dealer. And don't forget to measure the pressure of the spare tire – you never know when you might need it.
- Check for uneven wear, which can be an indication of chronic under-inflation or over-inflation, improper wheel alignment or tire balancing, or a problem with the suspension system.
- Check for imbedded stones, glass or other foreign objects that could work into the tread and cause a leak.