When used properly, it is in most cases, since the manual transmission is more efficient (lower internal losses), especially when compared with the traditional automatic transmissions with a torque converter.

It depends.

Generally, if an automatic transmission has the same, or fewer number of gears, then the manual will have better gas mileage, as there are some losses associated with the torque converter.

Now that automatics can have 8+ gears, they tend to outperform manuals in terms of MPG. A well driven manual could potentially equal or exceed them in some cases, however, as far as the average user is concerned, the automatic is better.

This brings up another point- in that the gas mileage you will get out of a manual transmission car is more dependent on how it is driven than the same car equipped with an automatic.

With that being said, I believe that CVTs will become dominant in the mass consumer auto market as they are the best option in terms of utilizing engine power efficiently and getting good gas mileage.

It can be if you drive appropriately and don't drive in too low a gear and drive on the highway a lot since it is less weight and you can ensure you kep the revs low but for city driving most people are better off with an automatic with lots of gears or a cvt transmission

That used to be true, these days with lock up torque converters there is not much difference. New generation 7-8 speed automatics promise to be more efficient yet.

Hi this depends upon the nut behind the steering wheel.