In performance mode Subaru have locked the CVT out — any change in revs means a change in speed. CVT transmissions also cannot handle as much power as conventional transmissions, although this is slowly changing.
Small industrial vehicles such as light tractors often use them, and you see them on snowmobiles too. It should be smoother and quieter too. However, the more of those advantages you get, the more the car feels motorboaty, where you get that strange sensation of increasing speed with the engine revs staying the same.
First Name:. Email address:. Great article thank you. We are just about to buy a Mitsubishi Outlander with cvt and this article has really helped me get my head around why everyone keeps saying it takes some getting used to. Smoother acceleration, better gas mileage, driver can pay more attention to the road. Less maintenance. No learning curve for new drivers. CVT you have to replace the whole transmission when it is bad, there is no rebuild and it is expensive.
This is an informative and well written article. How do the pulleys change diameters? The gap between the sides of the pulley is increased or decreased according to the desired effect.
Decreasing the gap has the opposite effect; the belt rides higher, as if in a larger pulley. The trick is, in order to maintain belt tension, the two pulleys have to act oppositely in unison.
I guess only one pulley needs to be actively varied, while the other can utilize spring tension to close the gap thus maintaining tension. I used a drill press that worked on the same principle. No stopping the machine to move the belt to a different pulley… turning the hand wheel on top of the press allowed infinitely variable chuck r. By law these zones are 50, 40 and 60km however when travelling at these speeds the car jerks along.
I drove test vehicle in my usual manner and no gear change problem. I hate CVT. Can anyone offer possible solution please. Are you suggesting the car surges past the speed limit when you take your foot off the accelerator? Thanks Isaac. Hi Isaac, the surge is only there at low speed under 50km. When moving off I accelerate gently in one movement. With reference to the software update, he said on previous model the update would reset driving history so the car would adapt to any new driving style.
Another complaint that drivers tend to make about a CVT is the loud droning sound that occurs during acceleration. This happens because the CVT forces the engine to continuously run a constantly high rpm as it gets up to speed.
As Car Engineer explains, the general public has been less accepting of the CVT due to the difference in noise perception from mechanical or step automatic transmission. CVTs can be expensive to repair or replace when compared to a conventional automatic transmission. Some of the common problems that owners run into include overheating, slipping, and sudden loss of acceleration.
Shuddering is also a common problem. Since CVTs depend on the belts to operate, if these suffer from excessive stretching or too much wear, the transmission can completely fail. According to Mister Transmission , while there are some advantages to having a CVT, traditional automatic transmissions also offer some benefits. Like a CVT, an automatic transmission also has some downsides. Some of these include:. How Stuff Works explains that an automatic transmission uses gear sets, a hydraulic system, and a torque converter.
The hydraulic system regulates the bands and clutches that control the gear sets, and a pump pushes the transmission fluid through. The fluid pressure forces the shift valves to open and close, which opens different gear circuits. Now you know the difference between a CVT transmission and an automatic transmission. Which one works for you?
New Cars. Buyer's Guide. Type keyword s to search. Today's Top Stories. The first automatic transmissions were two-speed automatics, and these were quickly replaced by three-speed and then four-speed automatics.
Each successive change improved fuel economy and drivability, and so the trend continued on up through the numbers to the point where most current automatics generally have eight, nine or even 11 speeds. A higher gear count reduces the size of the steps between adjacent gears, and that has several benefits. Fuel economy improves because the engine is more likely to be operating at its most efficient rpm.
Likewise, more gears reduces the likelihood of back-and-forth dithering on grades because smaller steps keep the engine closer to its sweet spot in terms of power and torque. The presence of smaller steps also reduces the need for a slushy torque converter, a generally inefficient, power-robbing device that smooths what would otherwise be jarring shift-shock at each gear change.
A CVT maximizes the potential of this concept. And of course the degree to which a CVT lives up to the potential described above is only as good as the software that controls it. The main drawback that remains is one of perception and emotion, because a CVT changes how an engine sounds and a powertrain responds under acceleration. However, many have found the lack of traditional gear changes to be disagreeably odd, especially aggressive drivers who are more likely to run the engine hard.
The car can sound like it's perpetually stuck in a low gear. This is why many newer CVTs artificially create stepped gear changes — usually in a "Sport" driving mode, but sometimes in normal operation.
Now place the same gearset at the pedals, but flip it around. This gives the desired acceleration and power whenever you need it. Hence, you get both superior performance and matchless comfort. In effect, a CVT has an unlimited number of gear ratios.
This means that the engine will always be running at the most efficient RPM, for any given speed. And since the engine is allowed to operate in the highest possible efficiency band, it delivers enhanced fuel efficiency in different driving conditions. The best engineering never lets you know just how much work the mechanical parts are doing to give you a smooth drive, and in that respect, the CVT available in the Maruti Suzuki Baleno is right up there with the best.
A smooth transmission mated with a smooth 1.
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