AUTOMOTIVE TERMINOLOGY EXPLAINED

Readers of GoodCarBadCar are not always car enthusiasts, aficionados, or even addicts. Dare I say it, some readers are actually researching, perusing, or attempting to garner an aficionado status.

For these individuals, words and phrases like: forced induction; engine capacity; crossover; torque; direct shift gearbox, and other such things that are do not relate strictly to the automotive world, but when applied herein can become confusing. Confucius to the rescue, then. Rather, The Good Car Guy. When explanations are required, 'Answers' will be provided. Just email goodcarbadcar@gmail.com if there are more terms that boggle or baffle.

Considering The Good Car Guy's lack of engineering credentials and the likely lack of many readers' engineering qualifications, this 'Answers' page won't dig too deep. Just enough so that your next trip to GoodCarBadCar can be an enjoyable and understandable one.


HORSEPOWER AND TORQUE: Around 200 years ago, James Watt decided that one horse can raise 33 pounds of coal 1,000 feet in 1 minute. Or 330 pounds of coal 100 feet a minute. It works out to 33,000 ft-lbs in one minute, and that's a horsepower. Just the one. (You're beginning to see the relation between horsepower and torque.) In fact, to discover the horsepower of an engine, you actually measure the torque and then do an equation.

A dynamometer, with one car sitting on its rolling road, will tell you the torque that car is putting to its wheels at whichever rpm's you desire. Push the throttle to 1500 rpm, and a car will likely make less torque than it would at 4000 rpm. Once you know the engine's torque, you multiply that number by rpm/5252. A car with 200 lb-ft of torque at 4500 rpm makes 171 horsepower at 4500 rpm. (4500 ÷ 5252 x 200 = 171) This is the chief reason torque can be a better tool to realize your car's real-world driving potential. A high horsepower car will likely feel strong at the top end of its rpm range and at high speeds.

A car like the Honda S2000. But that same car has little torque and can feel weak at low rpm. If I were to drive an S2000 not knowing its engine output, I would guess that it makes plenty of horsepower based on the way it screams from 6000 rpm to 8500rpm. But I would know that the way it reacts from idle to 4000 rpm is representative of a low torque car. Its official stats are 237 horsepower and 162 lb-ft of torque.


ENGINE CAPACITY: That may not be the typical term by which readers grow confused. Maybe you seek out car dictionaries, or give up altogether, when you hear about the 182bhp, 160 lb-ft of torque 2.0L four-cylinder.

Alrighty then. If that's you; listen up. Most modern engines are four, six, or eight cylinders. Some high performance and high-luxury cars use ten or twelve cylinders. Some city cars, such as the smart fortwo, use three cylinders. And a few cars even use five cylinders.

Assume for a minute that you hear your friend say they have a new Honda Civic with the 2.0 litre 'four'. You have no clue what he is talking about, but since this is a relatively common thread, you follow along. The 'four' relates to the number of cylinders inside the car's engine. (GCBC is assuming you understand engine. The thing under the hood that makes the car powerful. It produces the go.) Inside a cylinder lies open space that is filled by a piston. The piston pumps up and down. The volume of the space in which that piston moves, when multiplied by the distance from the top to the bottom, will give you the cylinder's capacity. But that is just one cylinder, and your friend's new Civic has four such things. They're all equal, and so you simply multiply by four to achieve that 2.0 litre signification.

Each cylinder in that engine is 499.5 cubic centimetres, so the engine capacity as a whole is 1998 cc's. Car engines are always rounded to two digits. Even with other terms you may hear - crankshaft, valve, camshaft, connecting rod, spark plug - it is simply the swept volume of the cylinder x the distance the piston travels inside it that determines the capacity of the engine.

Typically, four-cylinder engines grow no larger than 2.5 litres. A six-cylinder engine does have a great capacity to go small or grow big, but is not commonly found larger than 4.0 litres, and more normally between 2.5 and 3.5. Eight cylinder engines are all over the map. Chevrolet sells a Corvette with a 7.0L, while Ferrari's previous entry-level car had a 3.6L eight cylinder. Twelve-cylinder cars usually range up from 5.0 litres, and ten-cylinder engines, though few and far between, seem to live in the same range as the twelves. Many car engineers would believe that 500cc per cylinder is a nice and safe number. That would lead you to 2.0L four cylinders, 3.0L six cylinders, 4.0L eight cylinder engines and so on.

Engine configuration is one more interesting tidbit that goes along with capacity. These days you hear of inline-sixes, V8's, flat-sixes and so on. Inline engines, used most famously by BMW, simply arrange their cylinders in a row. V shaped engines arrange the cylinders in a vee, and flat engines punch their cylinders horizontally. That's why they call them boxers. Inline engines usually have four, five, or six cylinders. V's are normally sixes, eights, and twelves. Boxer engines, made by Porsche and Subaru, are four or six cylinder engines. The W formation is little known, but used in high-class cars including the Audi A8, Volkswagen Phaeton, Bentley Continental, and the Bugatti Veyron. As W-12's in the first three, as a W-16 in the Bugatti. Now you know what the friend will mean when he comes home with his new Porsche and its 3.2L boxer six. Phew, 'nuff said.

CROSSOVER: Relating not to a musician's ability to sell one song to radio station's of differing genres, but to a vehicle's ability to sell itself as multiple things to multiple people. Crossovers could be called combinations, but it wouldn't sound nearly as 2007 as we like. Crossovers take bits and pieces, or bits and pieces of ideas, and mold them into one article. Take the best of a sport-utility vehicle - its high ground clearance and ability to seat all the kids - and combine it with the underlying architecture of a car. That foundation will allow for a lighter vehicle with easier and more pleasurable driving dynamics. You'll still look like you're in a sport-ute, but you won't be in need of your own oil well or an extra propulsion system. Crossover can't be considered such a narrow-minded term, however.

Try a regular station wagon, such as the Volvo V70: raise it, plaster it with sport-ute style body addenda, mandate a roof rack and knobblier tires, paint it in earth-tone shades, and there you have it. An SUV wagon, the Volvo XC70. You're driving what is truly, verily, really the same Volvo as everybody else, but it just looks tougher. Doesn't handle quite as good, since its centre of gravity is too lofty and its tires too tough, but it really is the same.


ROADSTER: Got yourself a two-seat convertible that could be raced in a pinch? You've got yourself a roadster. The aforementioned S2000 is a good case in point. A tight-handling car with sharp steering, plenty of revs, and a solid structure like the S2000's just needs some Avon race tires and some upgraded brakes to head out to Laguna Seca for 30 laps. Porsche's Boxster, the BMW Z4, Mazda MX-5? Roadsters for sure. Chrysler Sebring? Not so much. More to come, so hang on if your confusion has not abated.