Globe Drive

After more than a century, automotive argot has developed into a rich vernacular “shorthand”, but - like the oil locked in Alberta’s tar sands - some processing is required to get at the stuff that’s actually useful.

In this attempt at translating “car speak” into plain language understandable by non-car-enthusiasts, we’ll take a look at the engine – or is that motor? – and transmission (also known as the drivetrain). And what the terms used to describe their attributes by Globe Auto reviewers or car sales reps actually mean in terms of day-to-day driving and ownership.

THE ENGINE – PRIME MOTIVATOR

Firstly, engine or motor is acceptable and virtually all automotive engines work in the same way. A piston (wine cork) in a cylinder (wine bottle neck) is forced down by expanding gases (sort of the reverse of champagne) from burning fuel and air and turns a crankshaft that changes this reciprocating action to rotary motion (now think pumping legs and bicycle pedals).

Engines, like cases of wine, come in different configurations. Commonly they will have four, five or six cylinders arranged vertically inline or horizontally opposed also known as flat or boxer engines, as the pistons “punch” back and forth. There are also V-6 and V-8 types, plus V-10, V-12 and even V-16s, with banks of cylinders that form a "V" shape.

But none of this really matters, what does is the performance and fuel economy they generate.

Displacement describes the “size” of the engine and is usually expressed in cubic centimeters or rounded up to litres. Smaller displacement engines in the 1.0 to 2.5-litre range produce less power, typically 70 to 175 hp, but generally deliver better fuel economy than larger engines displacing three litres or more and making from 200 hp to well over 500 hp.

TURBOS AND BLOWERS

Engines normally inhale the air and fuel mixture they burn at the same atmospheric pressure we humans do, but forcing more in with an air pump called a turbocharger (turbo) or supercharger (blower) ups the power of any engine type.

Subaru’s normally aspirated 2.5-litre boxer four is rated at 170hp, for example, but in turbocharged form 224hp. BMW’s 3.0-litre six-cylinder engine’s output jumps from 230 hp to 300 hp with twin-turbochargers added.

But how power is made doesn’t matter much either. As long as the performance being delivered is adequate to meet your driving needs and expectations.

If you live in hilly country, or plan to tow a summer camper trailer, opting for a V-6 or even V-8 vs a four-cylinder might be sensible. Larger vehicles with small engines can sometimes be pretty dispiriting to drive, but there is usually a fuel economy penalty attached to increased performance.

That non-turbo Subaru engine’s ratings are 10.6L/100km city and 7.3L/100km highway, while the turbo-motor’s are a thirstier 11.2L/100km city and 8.0 L/100km highway – and it requires premium fuel.

Ford’s V-6 Mustang is rated at 12.1L/100km city and 7.8 L/100km highway and the V-8 13.7 L and 8.6 L respectively.

FUEL – AN EXPENSIVE NECESSITY

Always determine what the octane rating (too arcane to explain here), or recommended fuel type is (regular, mid-grade or premium), which can vary in price by as much as 15-20 cents a litre and add considerably to your fuel bill.

Diesel engines work essentially the same way as the gasoline fueled variety, but can be from 25 per cent to 30 per cent more fuel efficient and today’s often turbo-charged versions are powerful, quieter and don’t smoke. But you pay an up-front premium for them and diesel fuel can be more expensive than gas, which means if you don’t cover a lot of miles, they may not make fiscal sense.

Another alternative that needs close study are hybrids, which combine gasoline engines with batteries and electric motors to reduce fuel usage and thus greenhouse gases.

Saving the planet may be a worthwhile goal, but you have to determine exactly what you’ll actually be accomplishing and what it will cost you, as you’ll pay a premium for these vehicles too. Things like performance, battery replacement and resale value could be issues as well.

If you’re determined though, simple (relatively speaking) hybrids that stop the engine at traffic lights and restart when you move, and perhaps provide a little extra shot of power, are less expensive to buy and more practical than full hybrids which can run on battery power alone.

TRANSFORMING ENERGY INTO MOTION

Think of our “legs and pedals” analogy and the gearing that allows the rider to make the most of the power he or she can generate to go fast on the flat with ease, or climb steep inclines while we look at the gearbox or transmission.

Automotive transmissions do exactly the same thing and traditionally came in two basic types, manual or automatic. In the past manual transmissions could be counted on to deliver better economy, but modern multi-speed automatics now often do better. With either type the more gears or ratios (as with a bicycle) a transmission has the better. And by having overdrive top gears (that use less engine RPM or revolutions per minute for a given speed) can increase fuel economy.

Some transmissions are known as manumatics as they can operate automatically or in a mode that let’s the driver shift between the ratios, often with steering wheel mounted paddle shifters. These are of dubious value for most drivers.

Becoming more common are continuously variable transmissions (CVT), which automatically delivers a seamless and stepless (unless otherwise arranged) drive. These are efficient, but some can feel and sound odd to drive. Make sure you like it before you buy.

Other new types are the direct shift gearbox and the twin clutch gearbox, which have gears like a manual transmission that are shifted automatically or by the driver. They’re highly efficient, but can be a little rough in auto-mode.

FRONT, REAR OR ALL FOUR WHEELS

With a rear-wheel drive (RWD) vehicle the transmission sends power to the rear wheels only and with a front-wheel drive (FWD) just to the front. There are benefits to both, but FWD’s traction benefits make it a better way to go with most vehicles.

Four-wheel drive (4WD) was traditionally the preserve of sport utility vehicles, but is now becoming – usually referred to as all-wheel drive (AWD) – more common in passenger cars and crossovers. The two terms essentially mean the same thing, although the latter usually refers to a full-time system that requires no driver input.

Both deliver power to all four wheels, which can balance power delivery and enhance stability in slippery conditions, but aren’t the winter safety panacea some would suggest. A set of winter tires is all you really need in most circumstances.

Thoroughly test drive whatever combination of the above you decide on to make sure it meets your requirements.