Have we all gone mad? Do you really need to change more than 10 gears, and various clutches?

One of the surprises – concerning – the last month has been the knowledge of a revolutionary gearbox of Honda, that would be 11 gears operated through 3 clutches. We talk about surprise relative, both would not be the only manufacturer that is already betting on ten or more ratios in their automatic gearboxes. Even in a continent, like Europe, in which the automatic changes have not traditionally been as popular as the manuals, each time sold more cars without the third left pedal for the clutch, and automatic transmissions are gaining ground to become, perhaps, the standard of the cars that we drive within a few years. But why this obsession with increasing the number of gears and clutches? Do you really have sense?

why it makes sense to increase the number of gears?

The reason for a change with more gear ratios is to minimize the fuel consumption, and therefore maximize the efficiency of a car. With more exchange relations will be more easy to find an ideal relationship for the speed, and the driving conditions, which apply in every moment. It could be said that, in some way, by increasing the number of exchange relations, we would be approaching a change “auto” is able to offer infinite gear ratios, simplifying a lot of it would be that I would get a continuously variable transmission, a CVT, which by its nature offers a great efficiency, especially in hybrid applications.

If we already have changes type CVT, why not use them? The changes of variable type continuous, as the CVT, they are efficient, robust, economic, and soft, in both the lack of gears themselves, also they get rid of the slippage when going from one gear to another. But the reason why they are used, generally, in a very narrow spectrum of gasoline & diesel passenger cars, besides hybrids, is not other than the fact that they are not too intuitive, or rewarding, to the driver.

perhaps that is the reason why it is advocating for changes with technology torque converter and dual-clutch, with a lot of relationships change, to find a balance between efficiency and performance, and create change intuitive. But, as we will see below, in this strategy, there are other drawbacks.


why it makes sense to increase the number of clutches?

There are many advantages of a change of double clutch, but after trying a good change of torque converter, we always wonder if it is necessary to employ a dual-clutch products without a court marking sports.

After you have tested certain changes automatically, modern, with a torque converter, we have come to ask ourselves if certainly it is necessary to use changes of double clutch in products without a court marking sports. Still, we can’t deny the evidence. With the use of a second clutch, this type of change – the famous DSG, as those employed by the Volkswagen Group – to achieve an effect as important as, or more, as the fact of finding the ideal relationship at any time, the to reduce the slippage, and to mitigate the interruption of the torque transmission, when shifting from a gear pair, a gear odd.

The only reason we can think of that a manufacturer, like Honda, could bet on changes over two clutches, it would be precisely that of increase the number of gears while preserving the compact dimensions of the gearbox. The design of a change with several clutches would shorten the length of the block of the gearbox.

But here a new problem, the problems which leads to increasing of exchange relations.


When more clutches and gears don’t solve the problem, but it worse

years Ago, one of the manufacturers of transmissions with the best reputation in the market and good products, by the way, already alerted to the problem of further increasing the number of exchange relations. ZF warned that further increasing the number of speeds of a gearbox would end up being counterproductive.

counter-productive for a very simple reason. On paper, with the use of most relationships change and we get an advantage to improve efficiency, reduce consumption and emissions. And this is one of the main fields of battle in which they are fighting today manufacturers. The problem is that the drawbacks of such a strategy, as the increase of the complexity of the change, the increase of its size and its mass, and, above all, its excessive cost, just doing that the advantage gained hardly compensates for all the inconveniences. And in a landscape in which pose another type of solutions, such as hybridization, that is more than enough for us to wonder if not there are other paths worth exploring.

And maybe that’s the reason why we should watch with care, and great interest, to Honda and this new development. What will have made in Japan a change with a greater number of gears, greater efficiency, without excessive complexity and a mass and a size of contents?