Okay, I just bought a new car, and it is an automatic transmission. Having test drove several different makes and models of cars, I found that cars with CVT transmissions seem smoother, then automatic transmissions that feel like a regular manual gear transmission except – well automatic…. Then I also tried a car with a DSG transmission, and it felt like something in between… which was nice.
Anyway, I wanted to know what’s the difference and here is my main source of information, that I’ve cross referenced with other sites to ensure that the information is correct: http://www.hydraulictransmissionreviews.com/dsg-and-cvt-whats-the-difference-what-are-good/
But here’s a low-down on the difference:
1) Automatic Transmission – It is essentially like a manual gear on a car, but in order to transmit the power of the car to the wheels, it uses a fluid. So where you have a clutch, you have a box with fluid in it, that makes the gear shift smooth. Why a fluid? Well, anyone who’s driven a manual car will know that changing gears is a tricky exercise, it is a balance between the clutch release and the accelerator.
When automatic transmission were first created, trying to get an old computer to figure out how to do it was a huge challenge, so a fluid was used. This resulted in lower performance resulting in less fuel economy. Which is why the general assumption that automatic cars burn more fuel is still more or less correct today.
2) CVT was created to solve that problem – CVT is Continuously Variable Transmission. By using a belt style “gearing” system where power is transmitted to the wheels by tightening or loosening the belt, there was no need for a “gear” box, and so technically speaking, CVT transmissions don’t have gears; or some would say, has an infinite number of gears.
This way of transmission of power made automatic cars very smooth, because gears don’t shift, they become bigger or smaller where necessary. Which also resulted in a much more fuel efficient car since power is transmitted directly to the wheels without going through a fluid medium.
3) DSG is the latest technology (well kind of) – DSG is also known as the Dual Clutch system. This one is complicated to really explain, but essentially what they did with this type of car transmission is to re-introduce the Clutch. My guess here is that computers became smarter.
But because of the introduction of a “clutch”, DSG uses 2 couples to get around the tricky balance of clutch and accelerator that manual car drivers are familiar with. Again, I can’t explain the science of how it works but it results in a traditional gearing system, but with a much smoother and smarter gear shift, which some car enthusiasts will say gives you better torque, better power transmission, and hence better fuel savings.
So anyway, this is what I found out, and please do correct me if I’m wrong.