LinhPTK | May 29, 2017
The focus has turned and efficiency takes precedence in the modern car, but can there be a balance struck between outright economy and dynamic performance?
Times change quickly, and, of late, there are more advances in technology than many thought would even be possible. The primary reason behind this trend is a combination of rising oil prices, getting more out of less, companies wanting to maximize profits and environmental awareness–not necessarily in that order. Car manufacturers have worked endlessly to deliver more from each car. While some focus on design and performance, many have specific models created simply to eke out more out of every drop of fuel.
One of the creations in this respect is a gearbox with more ratios and twice the number of clutches as has been dictated by convention thus far. Twin-clutch transmissions have been around for a while now, but they’ve made do with six or seven speeds. Now though, the new breed are sporting as many as nine ratios and this has more to do than just plain fuel economy.
You see, each time an gearbox shifts up or down a gear, the resulting change of power delivery is complemented by a corresponding increase or decrease in fuel economy, depending on how much work the engine is actually doing. With five gears, there is a certain spread of turns from the output shaft of the engine, to the final drive which actually delivers the power to the wheels. Adding more ratios here will allow better harnessing of the power depending on the situation. This is why there are manufacturers working on nine-speed automatic transmissions. And the names are big – Mercedes-Benz, Land Rover and Jeep.
Mercedes E350 BlueTEC
Mercedes-Benz had introduced the facelift W212 E-Class with the 9G-Tronic automatic transmission in the 350 BlueTEC model. The 3.0L V6 turbo-diesel engine makes a healthy 265 hp and a rather mammoth 457 lb-ft of torque. While this engine has been seen before in other models, including the big GL-class, it always had seven ratios to play with. Now, with the E350 BlueTEC using the company’s new nine-speeder, there have been massive gains in not just economy, but overall feel and driveability as well. The seamless nature of the gearbox is evident from the moment you drive the car. The first ratio is 5.50:1, but the last three ratios are overdrive, with 0.86, 0.72 and 0.60:1 respectively. Emissions are in the 138-148g/km range and the car is stated to deliver a fuel consumption figure as low as 4.7 litres per 100 km, or 50 mpg US! Consider the claimed 0-100 km/h sprint time of 6.6 seconds and you know Mercedes-Benz are definitely on to something. Not too bad for a near five-metre long luxury saloon, is it?
Another exciting prospect is that of seeing the new GLA-Class compact crossover packing a torque-rich but efficient diesel motor with the 9G-Tronic transmission on offer. Having it ready for front-drive application seems to be a matter of when rather than if for the German giant.
Range Rover Evoque
The second car to receive all of nine cogs is the Land Rover Range Rover Evoque. This smart new compact SUV (for a Range Rover) not just took the world by storm with its looks and abilities, but its road presence was the icing on the cake for many. The popular 2.2L inline-four motor makes 190 hp and 310 lb-ft of torque, enough for many in most markets globally. However, the 2.0L turbocharged petrol engine makes 240 hp and 250 lb-ft of torque. Both are paired to a new nine-speed automatic from ZF. One of the key highlights of this transmission is the ability to deliver on either the economy or performance fronts, when not balancing them both, of course. The drive modes allow the car to step up its dynamic abilities with quicker acceleration times when needed, for instance, when overtaking on the freeway, or deliver maximum efficiency by going up through the gears quickly to increase fuel economy by keeping engine speeds low. The low peak torque characteristics of the turbocharged four-pot petrol and diesel motors help these causes in no small part either. The Active Driveline System also switches from two- to four-wheel drive within 350 milliseconds when needed, further aiding the cause of economy when needed, or providing added traction and stability when the situation demands.
The new comer of the Jeep range was perceived as a quirky addition to the range, but under the skin, it boasts of modern powertrains and a cutting-edge transmission. The car was specifically created to cater to the growing demand for compact crossover SUVs and the Jeep brand, being as iconic as it is, decided to make one for themselves. In the US, the Cherokee offers a choice of a 2.4L four-cylinder MultiAir engine with 184 hp and 171 lb-ft of torque or a larger 3.2L V6 with 271 hp and 239 lb-ft of torque. Some markets receive the 2.0L MultiJet turbo-diesel engine with 140 hp and 258 lb-ft of torque. All of these engines are paired to an automatic transmission from ZF which packs, you guessed it, nine speeds. The new Cherokee is being held up in many markets but will soon be delivered to their new homes and their eager occupants. With the 2.4L four-cylinder motor, the company claims an efficiency of 30 mpg (US) with regular gasoline. With a choice of two- or four-wheel drive and a number of trim levels, there are options for many who seek a new Jeep in their garage.
Automatic transmissions have had a lot said about them. Many say that the fun factor is taken away, while admitting to the obvious convenience in city traffic. Others like to have the car shift for them and, in cars with paddle-shifters, some of that fun just kind of makes its way right back in!