Your car’s transmission performs one of the most important functions in your vehicle. Understanding how it works can help you realize when it isn’t functioning correctly and how to avoid practices that may damage it. Read on for some insight into this fundamental part of your vehicle and the differences between automatic and manual transmissions.

The transmission of your vehicle can be described as a funnel. It takes very narrow outputs of energy from the engine, and translates it to a large range of speeds in a variety of ways. For instance, on flat ground, driving at 50 mph can be done with low RPM in a higher gear than if you were trying to maintain 50 mph going up a steep incline.

If it were not for the variable gearing provided by transmissions, you would have cars are stuck in a gear ratio and only able to accelerate to a certain speed. (For example, if you wanted a car to have a top speed of 100 mph, then it would be like driving a car in 4th gear all the time.) As you would soon find out, you would have no acceleration starting out with this gearing, and then you would redline almost constantly when you were on the highway. This car would wear out extremely quickly and be almost impossible to drive.

Put another way, a car without a transmission is like a one-speed bicycle—not particularly useful for anyone other than children. The gears your vehicle has are what give it usefulness and more capability.

That said, there are several key differences between an automatic transmission and a manual transmission. Automatic vehicles have several benefits when it comes to their transmission. They tend to be less expensive to maintain, because manual transmissions use a clutch plate and at some point the clutch will need to be replaced (which is a fairly major expense.) In an automatic, hydraulic fluid is used in lieu of a clutch plate, so if you’re looking to keep down costs on transmission maintenance an automatic may be the best way to go.

Another benefit of automatic transmissions is that they allow for computer control, whereas manual transmissions generally do not. (Manuals can have automatic clutches, but this isn’t widespread.) For this reason, it’s likely a vehicle with an automatic transmission will perform better in terms of emissions and fuel economy because the engine and transmission can be synced much more closely and narrow the margin of error.

It seems that automatic transmissions are often the best choice for the average motorist—but manual transmissions are not without benefits. In heavy duty applications, such as big-rig semis, construction equipment, etc., manual transmissions are preferred because they’re inherently stronger and able to take more abuse. This is often the case in racing applications as well, where manual transmissions are also preferred because they weigh less than automatic transmissions.

Mechanically, the main difference between a manual transmission and an automatic are the number of gear cogs. In a manual transmission, there are many gear cogs, usually one per gear, and you manually change to each gear. In an automatic, a single gear is paired with other auxiliary gears to get the same gear-range.

For more information on transmission maintenance and transmission repair, or to contact one of our expert transmission mechanics, visit As your Colorado transmission specialists, we’re happy to assist with all your vehicle’s needs. Those who know, go to AAMCO!