We return to the subject of automatic transmissions and their fuel economy, because the progress seen in recent times has been remarkable. Many manufacturers are now offering automatics that are far more economical than in times past, although the infamous EC economy figures will rarely be delivered in real life, just as is the case with manual transmission cars. What is remarkable is that automatics, traditionally thought to be thirsty, are increasingly matching, or come close to many manual transmission cars for fuel economy, and sometimes even beating them.
Jaguar’s forthcoming XE delivers results of 74.3mpg for the six-speed manual, powered by the new Ingenium 2.0-litre engine, and only drops down to an amazing 72.4mpg when fitted with the eight-speed automatic, taking it well clear of all its German rivals. The number of transmission ratios give a clue to this, and in other cars with efficient automatic variants, because a well set-up automatic car has a far greater chance than the manual one of being in the optimum gear for fuel economy at any given time. And this is because it has one or more extra ratios from which to choose, and also because its computer-controlled automatic knows better than almost all drivers which is the best ratio to select in any given driving situation. And, although there are some energy losses in torque converter transmissions, these have been greatly reduced in recent years and, in open road motoring, the transmission will usually be locked to avoid such losses. Many automatics often now offer an economy or efficiency mode and there are added bonuses available here. As well as modifying the ratio change points for optimum economy, some transmissions, like Volkswagen Group’s DSG and S tronic gearbox, slip into neutral and coast when you lift right off the throttle in Eco mode, as with the freewheeling of past times, totally eliminating the engine braking resistance. You’ll be amazed when you see how far you can coast like this, and as soon as you touch the accelerator, you’ll be back into gear.
In contrast, do bear in mind that, whilst it may be fun on entertaining roads to slip the transmission into the ‘sport’ setting that’s usually offered, you will pay for your fun next time you fill up. You also do need to do your research carefully; Volkswagen’s new Passat 1.6-litre TDI engine, using the seven-speed dual-clutch DSG transmission, is more economical than the six-speed manual, but the reverse is the case with the 2.0-litre TDI DSG variants.
Some stepless CVT automatics and automated manuals without torque converters, like Citroën’s ETG, and even some dual clutch transmissions, have driving characteristics that at times aren’t as seamless and smooth as the traditional torque converter automatics; so do drive one before you buy and don’t just rely on favourable impressions of a manual transmission variant. But what sort of fuel economy you get will always depend on the nature of your motoring. Many automatics pull a significantly higher ratio in top gear than the equivalent manual gearbox, and this gives particular benefits in open road motoring and high speed cruising that are not indicated by the EC extra-urban cycle figures, where steady speed cruising is pretty much ignored. Don’t be pushed into, or away from, an automatic for a difference of three or four mpg, because the real life scenario often won’t be that clear-cut. But do avoid older used cars with five-speed automatics, and some with even fewer ratios, which will almost inevitably be very thirsty. If you do fancy two-pedal motoring for ease of driving though, or possibly because one of the users needs an automatic for physical reasons, the chances are that if the EC economy figures are close to those of the manual variant, you won’t pay much extra at the pumps by opting for one, particularly if you drive it sympathetically.