Sunday, 11 July 2010

On Automatic Transmissions




Dear reader, it will have not escaped your notice that there has been something of a revolution in the world of self-shifting transmissions recently. Starting in 2003, when VW launched their DSG system in the Golf R32, double clutch gearboxes (DCT) are now offered by every serious volume manufacturer. Even Porsche finally got their PDK transmission onto the market, only 25 years after using it first in the 956/962 sports racers.

Now I’m not disputing that DCT doesn’t offer some clear advantages over the old-style torque convertor gearboxes. There is little loss of power through the transmission (although interestingly I note that Porsche quote slightly lower top speeds for their PDK cars), the changes can be snappy as you like, and most systems offer a stack of closely arranged gears; at first 6, then 7 and now 8 speeds. DCT systems are also technically superior to the older generation automatic clutch transmissions, with their jerky changes, and the smell of burning clutch should you try and 3-point your Ferrari 360 F1 on a hill.

But inspite of various internet warriors claims to the contrary, they are undoubtedly automatic transmissions; they all lack a clutch pedal, they all have a fully automatic mode, and I’ve yet to find any manufacturer offering a PDK ‘manual’ as standard with a torque converter automatic option.

The manufacturers like to market these systems with all sorts of motorsport associations, emphasising the flappy paddles that can be used to select ratios in semi-manual mode, and of course playing on the fact that the F1 teams having been using something like it for years.

But road use is nothing like racing. In racing, there is only one objective – to reach the flag first, and everything else finds itself subservient to that goal. Add all those fractions of a second gained by gear changes measured in hundredths, and they mean the difference between a podium and nowhere. And unlike racing drivers, modern transmission CPU’s don’t miss gears, buzz engines, break gearlevers, or generally do very much else to wreck expensive and highly stressed racing transmissions.

Of course, that’s the real reason why manufacturers have introduced DCT transmissions in road cars. Its because we all use the gearboxes ‘wrong’ too. All the time. We insist in lugging along in top when we should use intermediates to gain performance, we rev the thing like blazes for no reason, we slip clutches, jolt gear changes, change up too early or too late, insist on sequentially down changing all the way through the gears when we come to a stop, and a hundred other abuses committed by the lazy, ignorant or overly enthusiastic drivers.

So DCT’s offer a much ‘better’ solution, they are more efficient, reduce emissions, are controlled by algorithms smart enough to enhance any driver, and can be overridden if desired. Just how good they have got can been seen when Audi report that 95% of DCT owners stick it in ‘D’ and let the CPU change gear, and Ferrari’s latest 458 supercar will be almost 100% DCT transmissions.

DCT is the new manual, and anyone who disagrees is a bearded old Luddite.

That’s me then. I’ve detested automatic gearboxes with a passion since I could drive, and no amount of marketing twaddle will convince me that the new tech. ‘boxes are anything better than a slightly less bad automatic.

Within a few miles, my usual happy interaction with the controls of my mode of transport turns into a one sided shouting match, as the wretched thing drops two gears to scream off down the motorway for 200 metres when all I wanted was a smooth torquey surge to ease past a truck, or changes up two gears as I ease off around the roundabout’s apex in preparation for a nippy exit. How can any algorithm, no matter how well conceived, decide if I am going to approach slow moving traffic with a view to overtake at the first opportunity, or cruise along behind because I’m turning off soon anyway? Or understand that I’ve just entered a 30mph limited village after 5 miles of flat-out hooning, so I just want to quietly potter through in 5th, not hold onto 1st until the 7500rpm red line, or a thousand other scenarios I encounter in my daily driving?

And while the DCTs might make gearchanging ‘better’ for most of us, for me there will always be the satisfaction of a perfectly timed, toed blip on the throttle as I brake and come down through the manual box, judging the amount of that blip on how many revs, how fast, and how heavily I’m braking.

I appreciate a lot of drivers won’t know what I’m on about, for them a car is simply another white good, maintained and fuelled under sufferance, and whose only function is to get them from A to B in comfort and with a suitable amount of prestige. Which brings me nicely back to Hong Kong, where almost every car you see has an automatic transmission, and the passage of every Ferrari is marked by the computerised blip of the throttle as the driver slows for another set of lights.

Perhaps it was put best in BIKE magazine recently, when the writer considered the new Honda VFR1200, which he was testing in DCT form; “So this is an option that broadens motorcycling and allows customers who haven’t got as much experience to forget about changing gear and to concentrate on the pleasure of the ride instead. Some customers won’t want this – that’s fine, that’s a choice. What we’re offering is an alternative way to enjoy riding. It’s not the future, it’s a future.

1 comment:

ChAsE said...

Automatic transmission and Manual transmission accomplish exactly the same thing but both are done in completely different way. In Automatic transmission, computer detects the speed and throttle of the engine to change the gear.

car gearboxes