Nine Ratios Is As Far As Mercedes' Auto Gearboxes Will Go
There was a time when the automatic gearbox was a thing of derision; with slow shifts, poor economy and rubbish software that always seemed to pick the wrong gear for any given situation, it’s easy to see why many dismissed automatic gearboxes and have never looked back. As technology has developed, however, automatic gearboxes have progressed to the point where they’re faster and more economical than any human could ever dream of.
Part of this progression has resulted in manufacturers chucking more and more cogs into their gearboxes, with the likes of GM and Ford now offering 10-speed transmissions. According to Autocar, Mercedes has called it quits in the race to offer a gear ratio for every occasion, saying that it has conducted “81 billion different computer simulations for gearbox scenarios and believes nine speeds work best.”
It’s probably a good thing. We’re all for progression, and many years ago it was deemed unfeasible for road cars to be drivable with the kind of power we see in performance motors today, however the gear ratio race was getting a bit silly; shifts are barely perceptible under normal driving, but the constant, minor changes in torque and engine note are noticable to those of us who care about such things. We were starting to reach a point where our cars would be spending more time between gears than actually engaged…
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inb4 “manual is always better”
very manual such better much clutch
10 gears huh? I’m beginning to think Koenigsegg has made a very good point with the Regera by removing the gearbox from the equation.
Apples and oranges here. Explain to me how do you imagine it working with 1500 less hp, namely 200.The ideal solution seems to be CVT, but for today it is too unreliable, requires maintenance and cant really handle bigger engines.
Vin Diesel does not approve.
Just a question: a manual transmission usually has 5+R or 6+R gears and works perfectly fine with it, so why do automatic transmissions have 9+R gears? Do they need more gears or do they have them because it’s something nice to have?
Somebody summon Engineering Explained please.
They don’t actually ‘need’ them, but having more gears means that the enige can be in the optimal RPM range for most of the time. This means beter fuel consumption and performance. The reason auto transmissions have more is simply because the computers are always working out the best gear to be in, providing you with optimum power or efficiency, depending on what you’re asking of it. When it wants to change gear, it can simply do so without a noticeable drop in power. Giving a manual gearbox 9 speeds would be ridiculous, since the driver would have to be shifting every 2 seconds when accelerating / decelerating.
Having more gears aids efficiency or acceleration, because for a given speed there will be a gear that will allow the engine to stay where it’s either the most powerful or the most efficient. Under hard acceleration the engine can stay at the high RPMs where it’s got the most power (VTEC yo), but for cruising the gearbox can find a gear where the engine is running near idle for maximum fuel savings.
It’s like having the best bits of a CVT without actually getting a CVT and dealing with a rubber band for a gearbox.
The highest amount of gears you’d find on a manual box is 7, and even then on very few cars (Porsche/Corvette Stingray) because lets face it, none of us are Dominic.
I’ve summoned him, he should be here shortly 😉
Among many of reasons, I’d reckon one of the biggest factors would be fuel economy. At 8th gear my petrol A4 runs under 1800rpm at 90mph…
Not many have that number of gears really, but it is to keep the engine in its most efficient range of power, if the car is doing more gears is not a problem, but people wouldn’t want to be shifting so much all the time, they like a wider powerband, the more gears also means the difference between each one is smaller as well so makes it smoother
Next Mercedes g365 amgs f12 BB must have like, 50 gears
Please tell Mercedes isn’t going to use the ZF 9 speed….
9 speed auto already available in conjunction with their diesel engines
exept sportcars (SLS, GT) Mercedes develops and builds his own transmissions.
I love the 8 speed auto in my RAM. Keeps the HEMI in the torque band through all 8, really gets her 5800 lb frame going when I need it. In some cases better gearing > more power.
I agree, Dodge has a really good 8 speed.
Jesus, I still cant fathom 8 speed gearboxes yet.
One fact nobody seems to mention, engines have become more powerfull over the years. That means more gears are needed to spread out the power and maintain grip, comfort etc….
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