Which is more fuel economic?

Question

I was just wondering, since I'm getting a new car in a few years, so I just wanted to know... Is an automatic or manual transmission more fuel economic? (Just in case, I don't 'dirt-bag' cars, meaning I don't accelerate aggresively, or go more than 5 km/h over the speed limit.)

Answer 1

On paper, a manual transmission will always be more efficient because an automatic transmission does not convert all of the input energy into mechanical motion, there is slippage within the transmission as well as with the torque convertor.

However, in practice, a driver can use bad driving habits which quickly offset the differences in efficiency. For example, not shifting soon enough/running the engine at higher RPMs will quickly rob you of fuel effiency.

Additionally, due to the substantial improvements - both in technology and design practics, the differences between automatic and manual transmissions are not that great anymore. Many (if not all) modern automatic transmissions have locking torque convertors as well as locking clutch packs internal to the transmission which have been optomized to provide maximum effiency <while still providing a comfortable ride>.

In the end, I would suggest you use your expected driving routine to determine which transmission you get. If you expect to drive in bumper to bumper traffic on a daily basis, you will quickly grow tired of using your clutch and regret not getting a manual transmission. Same can be said if you live in a very hilly area where life can be much more difficult if you have a manual transmission. On the other hand, if your daily driving is rather benign, then you may find having a manual transmission is no big deal. Either way, if you don't know how to drive a manual transmission, I recommend you learn, if for not other reason than as a "what if" skill.

I've owned, and have no strong preference one way or the other. My previous truck was a stick & my current truck is an automatic. Both have served me well.

Good luck!