Skip to main content
you & your car

Don Ryan

QUESTION: We're planning on our usual summer vacation period, which involves multiple trips to our cottage in the Muskokas. We have and need a full-size SUV because there are at least five of us most weekends, more for extended stays, and the associated gear.

With fuel companies hiking prices during the travel season, I have come to expect big bills every time I fill up but am reluctant to trade for a smaller, more fuel-efficient vehicle because of the compromises that would bring. Any tips to cut those fuel bills?

Andrew

Experts, studies dismiss superiority claims - but poll shows stereotypical beliefs persist

ANSWER: Your situation is common throughout the continent and industry. We have become accustomed to the comfort and convenience of larger vehicles and don't want to give that up because of fuel costs. While we still have some of the cheapest fuel in the world, we are becoming more aware of costs.

So, drive more efficiently and make sure your vehicle is ready as well. Tires and speed are my first tips.

  1. Top off those tire pressures at the start of each and every trip - at the upper end of the pressure scale listed in the owner's manual because you are filling the vehicle. Check the pressure when cold. Proper tire pressures can result in a 2 to 3 per cent mileage improvement, even if they're only a couple of pounds above what they were before you topped up.
  2. Cut your cruising speed. Instead of trying to stay with the pack at 120 km/h, lower your speed to 110. You'll get there five to 10 minutes later but that 10 km/hr alone could cut your fuel bill by up to 10 per cent. Use cruise control when possible as steady speed means less consumption.
  3. Try to avoid using a roof rack - that added drag can easily add more than 10 per cent to the fuel bill. Same thing with weight. Monitor what people are bringing and whether it is necessary or could be left at home or the cottage instead of carried back and forth each time. Do you really need to lug your golf clubs back and forth?

The bottom line is that you can improve mileage by 10 to 20 per cent through driving and preparation. That's a lot less expensive than trading for a smaller vehicle.

News, opinion, photos and videos, and more. Sign up and we'll send you the best stories of the week.

VALVE TIMING

QUESTION: What is variable valve timing? My salesman told me my new car had it and I didn't want to appear stupid.

Marylin

ANSWER: I doubt that 1 per cent of car buyers today what it means, or care.

Variable valve timing is one of the methods engineers are using to increase fuel economy and reduce exhaust emissions. It has been around for years, but has come into vogue with the need to meet tougher emission standards. It also allows improvements from an existing engine - a lot less expansive than developing and producing a new engine.

To explain very briefly, let's start with what valves do. There are two to four of these for every cylinder in an engine to let fuel and air in and spent gases out. When they open, how far they open and how long they remain open are all critical issues.

Without variable valve timing these issues are fixed. Regardless of engine speed, throttle position or other variables, the intake valve will open at the same point, allowing the downward movement of the piston to draw the fuel-air mixture into the cylinder. That valve will close at the same point. The exhaust valve or valves in that cylinder will open at the same exact moment regardless of speed or throttle position, allowing the rising piston to push the now-burnt air-fuel mixture out the exhaust pipe.

That has been the case for more than a century. But it has also been a compromise between valve activity necessary for a smooth idle and that at higher speeds where more air-fuel is needed and needs to be exhausted.

In the quest for more efficiency, to get more mileage and fewer emissions from each drop of fuel, and with the aid of modern electronics, engineers have developed a number of ways to change when valves open and close. This is known as variable valve timing.

Interact with The Globe