The Difference between an Automatic and a Manual Transmission
On the surface, the obvious difference between manual and automatic transmissions is simple and self explanatory. As the name would suggest, a manual transmission requires the operator to shift gears manually, whereas an automatic trans does all the work itsself. However, the inner workings of the two are much more complex.A manual transmission consists of a cluster of reduction ratio cogs on a shaft that is driven by a manually operated clutch (usually in the form of a pedal on the floor of the vehicle operated by the driver's left foot, or a lever on the left handlebar in the case of a motorcycle)and an idler gear which meshes with th gears on the shaft and turns the output shaft, usually with a final ratio of 1:1.An auto transmission uses hydraulic pressure in a device called a torque converter to drive a pump which pumps fluid through a series of fluid clutches, which are controlled by a series of circuts to vary the final drive. It is more complex than that, but that is the best way that I can explain it.The advantages of an automatic transmission are that gear changes are much quicker, and power delivery is much smoother, making them much better for stop-start style driving, or towing, but the disadvantage is that the torque converter saps quite a lot of power from the engine, and increases fuel consumption.The advantage of manual transmissionsis that the power is more direct, and therefore more efficient, and also provides more control, especially when going downhill, as the direct drive provides engine braking.The disadvantage is the level of skill required to operate one correctly. The level of co-ordination required is slightly beyond what some "drivers" are capable of.A manual trans is best for hard, sporty driving, and the auto rules for cruising.The choice comes down do the individual. Many people choose the manual for reliability, but the most indestructable transmission in history would have to be the Chrysler "Torqueflite" transmission of the 60's-70's, a heavy but bulletproof auto, now much sought after for drag racing.
