* Manual transmissions typically offer better fuel economy than automatics. Increased fuel economy with a properly operated manual transmission vehicle versus an equivalent automatic transmission vehicle can range from 5 % to about 15 % depending on driving conditions and style of driving -- extra urban or urban (highway or city). There are several reasons for this:
o Mechanical efficiency. The manual transmission couples the engine to the transmission with a rigid clutch instead of a torque converter that introduces significant power losses. The automatic transmission also suffers parasitic losses by driving the high pressure hydraulic pumps required for its operation.
o Driver control. Certain fuel-saving modes of operation simply do not occur in an automatic transmission vehicle, but are accessible to the manual transmission driver. For example, the manual-transmission vehicle can be accelerated gently, yet with a fully open throttle (accelerator pedal to the floor), by means of shifting early to a higher gear, keeping the engine RPM in a low power band. By contrast, in an automatic transmission, the throttle position serves as the indicator of how fast the driver wishes to accelerate. If the accelerator pedal is floored, the transmission will shift to a lower gear, resulting in high engine RPM and aggressive acceleration. The thermodynamically efficient combination of open throttle and low RPMs is unavailable to the automatic transmission driver. Fuel-efficient acceleration is important to achieving fuel economy in stop-and-go city driving.
o Fuel cut-off. The torque converter of the automatic transmission is designed for transmitting power from the engine to the wheels. Its ability to transmit power in the reverse direction is limited. During deceleration, if the torque converter's rotation drops beneath its stall speed, the momentum of the car can no longer turn the engine, requiring the engine to be idled. By contrast, a manual transmission, with the clutch engaged, can use the car's momentum to keep the engine turning, in principle, all the way down to zero RPM. This means that there are better opportunities, in a manual car, for the electronic control unit (ECU) to impose deceleration fuel cut-off (DFCO), a fuel-saving mode whereby the fuel injectors are turned off if the throttle is closed (foot off the accelerator pedal) and the engine is being driven by the momentum of the vehicle. Automatics further reduce opportunities for DFCO by shifting to a higher gear when the accelerator pedal is released, causing the RPM to drop.
* Manual transmissions are still more efficient than belt-driven continuously-variable transmissions.
* It is generally easier to build a very strong manual transmission than a very strong automatic transmission. Manual transmissions usually have only one clutch, whereas automatics have many clutch packs
* Manual transmissions are generally significantly lighter than torque-converter automatics.
* Manual transmissions are typically cheaper to build than automatic transmissions.
* Manual transmissions generally require less maintenance than automatic transmissions
* Manual transmissions normally do not require active cooling, because not much power is dissipated as heat through the transmission.
o The heat issue can be important in certain situations, like climbing long hills in hot weather, particularly if pulling a load. Unless the automatic's torque converter is locked up (which typically only happens in an overdrive gear that would not be engaged when going up a hill) the transmission can overheat. A manual transmission's clutch only generates heat when it slips, which does not happen unless the driver is riding the clutch pedal.
* A driver has more direct control over the state of the transmission with a manual than an automatic. This control is important to an experienced, knowledgeable driver who knows the correct procedure for executing a driving manoeuver, and wants the machine to realise his or her intentions exactly and instantly. Manual transmissions are particularly advantageous for performance driving or driving on steep and winding roads. Note that this advantage applies equally to manual-automatic transmissions, such as tiptronic.
o An example: the driver, anticipating a turn, can downshift to the appropriate gear while the steering is still straight, and stay in gear through the turn. This is the correct, safe way to execute a turn. An unanticipated change of gear during a sharp turn can cause skidding if the road is slippery.
o Another example: when starting, the driver can control how much torque goes to the tires, which is useful for starting on slippery surfaces such as ice, snow or mud. This can be done with clutch finesse, or possibly by starting in second gear instead of first. The driver of an automatic can only put the car into drive, and play with the throttle. The torque converter can easily dump too much torque into the wheels, because when it slips, it acts as an extra low gear, passing through the engine power, reducing the rotations while multiplying torque. An automatic equipped with ESC, however, does not have this disadvantage.
o Yet another example: passing. When the driver is attempting to pass a slower moving vehicle by making use of a lane with opposite traffic, he or she can select a lower gear for more power at exactly the right moment when conditions are right to begin the manoeuver. Automatics have a delayed reaction time, because the driver can only indicate his intent by pressing the throttle. The skilled manual transmission driver has an advantage of superior finesse and confidence in such situations.
* Driving a manual requires more involvement from the driver, thereby discouraging some dangerous practices. The manual selection of gears requires the driver to monitor the road and traffic situation, anticipate events and plan a few steps ahead. If the driver's mind wanders from the driving task, the machine will soon end up in an incorrect gear, which will be obvious from excessive or insufficient engine RPM. Related points:
o It's much more difficult for the driver to fidget in a manual transmission car, for instance by eating, drinking beverages, or talking on a cellular phone without a headset. During gear shifts, two hands are required. One stays on the wheel, and the other operates the gear lever. The hand on the wheel is absolutely required during turns, and tight turns are accompanied by gear changes. If the hand leaves the wheel, the steering will begin to straighten. In general, the more demanding the driving situation, the more difficult it is for the manual driver to do anything but operate the vehicle. The driver of an automatic transmission can engage in distracting activities in any situation, such as sharp turns through intersections or stop-and-go traffic.
o The driver of a manual transmission car can develop an accurate intuition for how fast the car is traveling, from the sound of the motor and the gear selection. It's easier to observe the lower speed limits like 30 km/h and 50 km/h without glancing at the instrumentation.
* Cars with manual transmissions can often be started when the battery is dead by pushing the car into motion (or allowing it to roll down a hill) and then engaging the clutch in third or second gear. This is called a push start or commonly, "popping the clutch."
* Manual transmissions work regardless of the orientation angle of the car with respect to gravity. Automatic transmissions have a fluid reservoir (pan) at the bottom; if the car is tilted too much, the fluid pump can be starved, causing a failure in the hydraulics. This could matter in some extreme off roading circumstances.
* It is sometimes possible to move a vehicle with a manual transmission just by putting it in gear and cranking the starter. This is useful in an emergency situation where the vehicle will not start, but must be immediately moved (from an intersection or railroad crossing, for example).