New Cars, New Words

January 19, 2016



What they mean by torque vectoring, dual-clutch transmissions and other terminology

Chicago Tribune / Aaron Cole / January 10, 2016 --

Cover photo: The Porsche Cayman GT4 Clubsport, shown at the 2015 Los Angeles Auto Show, has a 3,8 liter flat-six engine with a six-speed dual-clutch transmission (Daniel Acker / Bloomberg News)

 

 

As new cars become more sophisticated — and expensive — they are loaded with the latest technology that too often sounds like engineering shorthand. It is confusing at best, and intimidating every other time.

But savvy readers can equip themselves for success with a primer to the latest automotive jargon. The list is long, but the concepts are short.

In simplified terms, most of what carmakers offer on their cars falls into one of three categories: convenience, power or capability. Armed with the understanding of what terms mean and what you need, you can overcome any linguistic obstacle that could endanger your new car relationship.

Torque VectoringTorque vectoring

Despite sounding like the name of a superhero, torque vector is an overly complex phrase for a simple idea: going where you want to go.

Carmakers have used torque vectoring sporadically in recent years, but it's becoming more widespread as more buyers ask for all-wheel drive systems and as parts get cheaper and computers get faster.

Acura has used a torque vectoring system in its cars for more than a decade, making it one of the oldest systems around.

Engineers there describe the process of the automaker's torque-vectoring system like rowing a boat — the outside needs to spin faster than the inside to make the turn.

What is the difference between stability control and traction control?

"It basically lets you move power from side-to-side … and why that matters is twofold. There's the practical part of it — which is probably relevant to Chicago — and then there's the fun part of it," said Gary Robinson, manager of product planning for Acura.

The practical part of it is instantly recognizable to anyone who has skid over black ice.

In most cars power travels through the path of least resistance, which is why Honda Accords spin in mud like Curly on a dance floor. The Acura TLX — which is virtually an Accord underneath — doesn't have the same problem. When the wheels slip on one side, power is shifted to the other side that has traction. No brakes are involved with torque vectoring, which makes it keenly different than systems such as stability control and traction control.

What about the fun part of it? Torque vectoring moves power to the outside tire to steer a car faster through a corner.

When it's working, Robinson admits that it's quieter than a winter morning. In situations when one side of the car is slipping on ice — like driving up an iced-over driveway — it may take a second for the car to pull itself up.

But if you're really looking for a fun way to find out, try doing doughnuts in a snowy parking lot and notice how much tighter the radius of your circle gets. Extra credit: Stuff a few co-workers in the back and bring extra sick bags.

Electric-assist steering

Back when men were men and cars were terrible, the only assist drivers had for manually steering a car were "preacher curls" in their parents' basement. For the rest of us mere mortals, we need help to move 2-ton lumps into a parking space.

Up until around 15 years ago, a hydraulic pump powered by the engine multiplied every turn of the wheel to help turn a car's heavy front wheels. Before that, your granddad wrestled his 1947 Chevrolet stepside into a parking spot — taking down a black bear in the Adirondacks was easier.

Dave Lee, University of Toyota product education administrator said that the old-fashioned system left room for improvement.

"Parasitic loss from the engine to drive the pump resulted in lower mileage returns," Lee said.

Translation for us: Power going to the pump isn't power going to the wheels. Ditch the belt; gain mileage.

The problem with moving the pump off of the engine and into the world of computing is that many systems would over- or under-boost the steering help at the wrong time, which led to overly twitchy or completely dead steering. Ditching 50 years of engineering has its drawbacks, apparently.

Lee said that engineers have moved a long way from the early days of electric steering; the algorithms are hopelessly complex and moving closer and closer to an ideal amount of help, without taking away feel from the driver.

"I have to admit that some of the earlier systems were, a bit — lacking," Lee said. "But we've been at this a while and I don't imagine it changing anytime soon."

Translation: Unless the car weighs less than a wet sneeze, expect electrically boosted steering, and expect it to be good. Moving the belt off the engine also increases mileage by 3 percent to 5 percent, depending on the car.

Dual Clutch Transmission ExplainedDual-clutch transmission

Predicting what gear comes next is how dual-clutch automatic transmissions, also called automated manual transmissions, operate.

"Your next gear is always pre-selected in the other sub-transmission, regardless of whether you are shifting up or down," said Hector Arellano-Belloc, technology spokesman for BMW.

Without getting into the weeds, there are two ways automatic transmissions operate and none of them are interesting. A dual-clutch automatic is best visualized as two separate, constantly spinning set of gears: one spins gears 1, 3, 5 (and sometimes 7) while the other spins gears 2, 4 and 6.

When the car pulls away in first gear, the transmission spins up the second set in preparation. When the car's ready to move on, or the driver commands a shift, bang! The transmission selects the next gear and prepares the next logical gear in one-quarter the time it takes a human to blink. No, really.

For drivers, the noticeable differences will be immediate and long lasting. Most automated manuals still have a clutch that can, at times, seem like the car is struggling to take off — that's the immediate difference.

The long-lasting difference: good automated manuals are slowly replacing manual transmissions in many cars. Ferrari doesn't even make a row-your-own transmission anymore. That's because dual-clutch transmissions are more fuel-efficient — 6 to 10 percent in some cases, weigh less and learning to drive them doesn't require a frustrating afternoon in a parking lot.

Aaron Cole is an automotive freelance writer.



     Back to list