Will your vehicle transmission choice affect your mileage?
Entering the market for a new vehicle can be scary, to say the least. Magazine ads and salesmen are throwing words at you for which your previously adequate Fast and the Furious education failed to prepare you. Your trendy Aunt Sally, who lives in the city, is giving you completely different advice than your buddy Bill, who regularly attends the rodeo. You’re concerned about vehicle costs, and not just the stuff you pay upfront. The price of fuel is only rising, and you want to know which features in your vehicle will help you minimize that cost. In this post we’re going to talk about types of vehicle transmissions, and the impact that decision will have on your mileage.
The two main transmissions that you are likely familiar with are the automatic and the manual, so we’ll take a look at those first:
Manual transmissions tend to be the most fuel efficient option, although other transmissions are catching up quickly. The manual transmission features a clutch and a gear stick, both of which are controlled by you. The clutch connects the transmission to the engine and the gear stick allows you to select the gear. Because there is no complicated technology required to choose the gear for you, which would use up engine power, the manual transmission is typically more efficient.
The conventional automatic transmission is by far the most popular in North America. An automatic transmission shifts the gears for you, meaning you no longer need to worry about operating a clutch or stick. This requires the use of high pressure hydraulic pumps to drive the torque converter, which connects the transmission to the engine (the job of the clutch in a manual). Power is needed to drive those hydraulic pumps, making the automatic transmission require more fuel. That being said, technology has improved to the point where there is usually a difference of just a few miles per gallon, if at all, between automatic and manual vehicles of the same model. From a cost perspective, it is important to note that a vehicle with a conventional automatic transmission will set you back upfront anywhere from $600 to $1900 more than a manual, with the average extra cost around $1100.
Newer transmissions on the market include continuously variable transmission and the dual-clutch transmission, also known as the semi-automatic:
The dual-clutch transmission is a combination of a manual and an automatic – the transmission works in the same manner as a manual, however the driver does not operate the clutch. There are actually two clutches, which are both operated by a complex system of electronics and hydraulics. Drivers still have the option of changing gears themselves, but without the third pedal. The idea behind the dual-clutch system is that the gears can be shifted much faster. Semi-automatic, or dual-clutch transmissions, are more fuel efficient than traditionally automatic vehicles, however most are still less efficient than their manual counterparts.
Finally, the continuously variable transmission uses a basic pulley system to change from a low gear to a high gear continuously, rather than having a set number of speeds. This allows for an infinite number of gears, and makes for a much smoother ride. A CVT works to keep the engine at its optimum power range, increasing mileage by about 1-2 mpg depending on your driving habits, according to edmunds.com contributor Scott Memmer. Most hybrid vehicles operate on a CVT transmission. Again, CVT transmissions cost more upfront than manual transmissions – probably around $1200 extra.
The debate over which type of transmission is “the best” continues, even just in terms of fuel efficiency. In order for you to be able to judge for yourself, below is a table comparing mileage of several vehicles that are available with different transmissions. Based on this data, larger vehicles like trucks and SUVs appear to be more fuel efficient with automatic transmissions than manual, while manual transmissions in smaller vehicles are either a little bit more efficient, or equal to automatic transmissions. CVT was consistently more efficient than manual, with just one or two outliers. Dual-clutch, or semi-automatic, appears to have little consistency in terms of measuring mileage against manual transmissions. It is difficult to compare conventional automatic transmissions with either semi-automatic or CVT, since most models are only offered in one type of automatic transmission. Take a look for yourself!
|All measurements in miles per gallon||Manual Transmission|
|Dodge Challenger SRT8||14/23||14/23|
|Suzuki SX4 Sedan||23/33||25/32|
|Mitsubishi Outlander Sport||24/31||25/31|
*All factors, except for transmission type, are the same in each vehicle comparison (engine, drive, year, fuel type, etc.)
*All mpg data taken from the Environmental Protection Agency green vehicle guide or manufacturers websites. This means that mileage will vary, so you may get different mileage out of the vehicles above. If you would like to find out how to calculate your personal mileage on a potential vehicle, check out MyCarma.