A fancy word for the size of an engine (expressed as a volume, for example, a 3.5-litre engine). Big engines generate more power but guzzle more gas.
A measure of the rate an engine delivers work over a given time. “It’s directly related to the speed you can go,” notes Frederic Racine, a product planner for General Motors of Canada. Horsepower comes in handy when you’re trying to merge onto the highway or pass cars in a short amount of time. But too much horsepower can pump up your gas bill and send your insurance rates into overdrive.
A measure of the twisting force produced by your engine that plays a vital role in its pulling power. People who haul a trailer or heavy cargo need lots of torque. Sports car drivers also covet torque, as it influences acceleration.
Gasoline engines generate power through controlled explosions in the cylinders. The more cylinders, the smoother the firing pattern and the greater the power. However, an eight-cylinder engine burns more gas than a four-cylinder one. Vehicles with cylinders arranged in a row have in-line engines. If an engine has two angled banks of cylinders, it has a V motor, such as a V8 engine.
Stuff more air and fuel into a motor and you’ll generate more power without the constant fuel penalty of added cylinders. Turbochargers and superchargers force extra air into an engine, helping it “breathe” better and adding some extra oomph when you stomp on the gas pedal. Cars without these devices have “naturally aspirated” engines, a cool term meaning they breathe normally.
Variable valve timing
An-other high-tech way to make an engine breathe better when you need an extra burst of power, without adding gas-guzzling cylinders or in-creasing the displacement.
The measure of a vehicle’s resistance against air, as determined in wind-tunnel testing. Sleek sports cars and gas-miserly hybrid cars have low drag coefficients, while chunky minivans post higher numbers. Added air resistance, even from a small removable roof rack or a bicycle tied to the trunk, can decrease fuel mileage.
The distance between the front and rear wheels. “If you’re comparing two vehicles of the same length, the one with the longer wheelbase will have a better ride,” says Racine. It can also be an indicator of interior space, as automakers often stretch a car’s wheelbase to get a roomier passenger compartment. Of course, the best way to test a car’s interior space is to stuff three tall friends or family members in the back seat and see how loudly they complain.
· Make a list of all the features that are important to you before visiting a showroom.
· Be specific about your needs when speaking to sales staff.
· Don’t feel intimidated if you don’t understand all the terms in a car brochure. If you don’t know why a specific feature is important, ask for an explanation.
· Brochures can help narrow your choice, but test drives will truly highlight on-road differences between vehicles.