Manual transmission driving technique
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Cautions
Please note:
- This article only applies to cars and trucks equipped with a manual transmission, not to motorcycles, which also have manual transmissions but are operated using different techniques.
- This article is intended only as a helpful guide, and is no substitute for practice or training by a qualified instructor.
- Some countries prohibit driving a manual transmission to people who made their drivers license on an automatic transmission car -- you might have to take extra classes to legally drive a car with a manual transmission.
- The extra wear on a vehicle's clutch inevitably caused by a new manual transmission driver is likely to reduce its service life by at least a few hundred kilometres.
Beginning drivers
Driving a car or truck with a manual transmission can be daunting for beginners. In addition to the usual physical and mental skills required to drive any vehicle, a manual transmission beginner must learn to contend with an additional hand control (the gear selector), an additional foot control (the clutch pedal) and a lot more concentration, at first, on what various systems in the vehicle are doing.
Many North Americans would caution new drivers against attempting the additional burden of learning to operate a manual transmission until they have mastered the more basic driving skills involved in driving any vehicle by practicing in a car equipped with an automatic transmission. In Europe, almost all learner drivers start with manual transmission cars, but they may choose to learn to drive with an automatic transmission instead -- for example if they're handicapped, or if they find out they simply don't "get" manual transmission driving. However, such drivers will receive a driving license that is valid for automatic transmission cars only, and must pass a separate test before being licensed to drive a car with a manual transmission.
Theory
Internal combustion engines all share several limitations (compared to electric motors) that necessitate the use of some kind of transmission to make them practical:
- They develop little useful power at low engine speeds
- Their maximum speed is limited to a few thousand revolutions per minute
Due to these limitations, a hypothetical vehicle that had an internal combustion engine but not a multi-speed transmission would have a fixed ratio of engine speed to vehicle speed, and the range of speeds it could attain would be severely limited.
A transmission allows a vehicle to employ a variety of gear ratios in transmitting its engine's power to its drive wheels.
Learning to drive with a manual transmission
Beginning manual transmission drivers should avoid conducting their initial practice sessions on busy streets or in neighbourhoods with many children, pedestrians or cyclists. In fact, it's best to start out in a large, deserted parking lot.
Shift patterns
A car or truck's shift pattern is usually indicated by a small diagram on top of the shift knob. For most five-speed transmissions it looks like this:
1 3 5
│ │ │
├───N───┤
│ │ │
2 4 R
In many Volkswagens and all cars with six-speed transmissions, Reverse will appear in a different position, but the positions of the first through fifth gears are the most common used in the automotive industry. (Racing cars with non-sequential transmissions, and some high-performance passenger cars, use a different pattern that is better suited to high performance or race driving.) If you're unfamiliar with a car's shift pattern, study the shift pattern diagram until you're confident you know where first gear and reverse are located.
Neutral is often not indicated on the diagram, but can be selected by moving the shifter to the middle row between the odd- and even-numbered gears. Note that manual transmissions have no "park" setting. To park, engage the parking brake and (optionally) select first or reverse gear before turning off the engine, making sure you have the clutch disengaged until the engine is stationary.
Basics
Starting the engine
First, always make sure that the car is in neutral before attempting to start the engine, by either depressing the clutch pedal or moving the shifter to the neutral position. If you attempt to start the car in gear a lot of strain will be put on the starter motor and you will move forward uncontrollably. The clutch is in a disengaged state by depressing it and in an engaged state while no pressure is applied. Many vehicles have a switch that automatically disables the starting circuit until the clutch is fully disengaged. In these vehicles it is necessary to hold the clutch pedal while starting, and in those without the switch it is a good practice, as it disengages the gearbox input shaft from the engine lessening the strain on the starter motor.
Once the engine is running, keep the car in neutral until you are ready to move away. Remember to either keep the parking brake engaged or your right foot on the brake pedal until you're ready to move.
Stalling
When a vehicle's engine is turning at low speeds it is unable to provide much torque, and placing excessive demand on it will cause it to stop running suddenly, an event known as a stall. Stalling usually causes sudden, jerking movements of the vehicle.
The following behaviours are likely to cause stalls:
- At a standstill, engaging the clutch too quickly, while the engine is turning too slowly.
- Coming to a stop with the clutch engaged and the transmission in gear.
If you stall the engine, don't panic. It happens to all beginners and even occasionally to experienced drivers, and it's nothing to be ashamed of. Just step on the clutch, start it up again and try again. If you feel like the engine is about to stall, step on the clutch. If you get scared, don't forget to step on the clutch while you're instinctively hitting the brakes, otherwise you'll probably stall.
The clutches in different vehicles vary in their sensitivity and range of movement, so even a very experienced driver in an unfamiliar vehicle can stall its engine a few times until he or she becomes familiar with its clutch.
Moving
Starting off from a standstill can be one of the more difficult manual-transmission skills to master, but with practice it becomes second nature.
Because of their engines' limited torque at low engine speeds, most cars cannot be started moving from a standstill by simply releasing the clutch pedal--they will stall. Instead the engine speed must be increased (using the gas pedal) while the clutch is being engaged. The exception here is a diesel powered car. It is possible to move off from a stationary position simply by slowly engaging the clutch. Diesel cars are less common in North America than the rest of the world.
The amount of throttle required to avoid stalling while starting out varies depending on the particular vehicle you're driving, but in general the engine should be turning between 1000-1500 RPM (indicated on the tachometer) while the clutch is being engaged.
Beginners sometimes find the fine throttle control required to hold the engine speed within this range difficult. It helps to spend a little time practicing with the gas pedal, while the engine is running, the transmission is in neutral and the parking brake is engaged.
To start moving, make sure the clutch is fully disengaged, by depressing the clutch pedal, and the engine is turning at the appropriate speed. Then, gradually engage the clutch by releasing the clutch pedal. If you engage the clutch too quickly, the car will jolt forwards and backwards, and likely stall.
By the time the car is moving faster than a brisk walking speed, the clutch should be fully engaged, your left foot should be off the clutch pedal, and you'll be driving in first gear. You shouldn't go any faster than about 20 km/h (12.5 mph) in first gear, so it's probably best to practice this in a large, deserted parking lot where you won't impede other motorists.
Stopping in first gear
To come to a stop in first gear, disengage the clutch by pressing the clutch pedal with your left foot while applying pressure to the brake pedal with your right foot. The timing isn't important, except that if the clutch is still engaged when the vehicle gets below walking speed, the engine will probably stall.
Once you're confident starting, driving around and stopping in first gear, you're ready to shift into higher gears.
Shifting
For a given speed of travel, the engine speed will vary depending on which gear is selected. So, when you want to change gears, you need to pay attention to the difference between the speed the engine is turning in one gear, and the speed it will be turning in the next.
The difference in engine speeds between one gear and the next varies between vehicles, but in general lower gears will have a greater difference than higher gears. For instance, at 15 km/h (9.3 mph), the engine might be turning at 3000 RPM in first gear or 2000 RPM in second gear, whereas at 100 km/h (62 mph), the engine might be turning at 2800 RPM in fifth gear or 3200 RPM in fourth gear.
With practice, you will become able to time shifts so that you can disengage the clutch, change throttle, shift and then reengage the clutch quickly without any jerkiness. Once again, it starts out difficult but becomes second nature with time.
Upshifting
When accelerating in any gear other than top gear, shift up when the engine is turning at too high a speed for the current gear. The engine speed that constitutes "too high" varies from vehicle to vehicle but is usually marked on most vehicles equipped with a tachometer as a red area called the redline. Running the engine past this speed can cause damage to internal components of the engine.
The vehicle's owner's manual should contain a table of recommended upshift speeds, but as a general rule of thumb consider shifting between 2000 and 3000 rpm. For maximum acceleration, one should shift just before reaching the redline, but for regular, everyday driving, to conserve fuel, one should shift at as slow an engine speed as possible without "lugging" the engine.
To upshift:
- Press and hold the clutch pedal with your left foot.
- Decrease throttle to a level appropriate for the higher gear. If you are experienced enough to shift quickly, you may be able to simply release the gas while shifting, and the engine will roughly sync.
- Move the gear shift knob, depending on the gear that is currently selected:
- To shift from an odd-numbered gear (i.e. 1st or 3rd) into the next highest gear, move the shift knob down, through neutral, to the corresponding position on the bottom row.
- To shift from an even-numbered gear (i.e. 2nd or 4th) into the next highest gear, move the shift knob up to neutral, one column to the right, then up to the new position on the top row.
- Gradually release the clutch pedal, allowing the new, lower engine speed to match up with the vehicle's speed.
If you take longer than a second or so to upshift, the engine will probably have slowed down too much for the new gear, and the car will probably jerk backward a bit unless you increase throttle to compensate. Don't increase the throttle too much though, or the engine will be going too fast for the new gear and the car will jerk forward. Once your skill at "matching revs" improves you can release the clutch pedal more quickly without any jerkiness.
Downshifting
When decelerating in any gear above third gear, shift down when the engine is turning at too low a speed for the current gear. The speed that constitutes "too low" varies among vehicles, but as a rule of thumb, consider downshifting when the engine reaches 1500 RPM. With some practice, you will be able to hear the engine speed and make this judgement.
Due to the larger differences in engine speed typically found between first and second gear, it's probably best not to downshift into first gear unless you plan to be driving very slowly for some time. Instead, stay in second gear and disengage the clutch when you're about to come to a stop. In some special cases (very steep slopes) first gear can be useful, however.
To downshift:
- Press and hold the clutch pedal with your left foot.
- Increase throttle to a level appropriate for the current speed of travel in the lower gear. This is (somewhat) optional, since gradually releasing the clutch will adjust for a slight mismatch, however if you completely release the accelerator while shifting you are likely to have the car jerk somewhat.
- Move the gear shift knob, depending on the gear that is currently selected:
- To shift from an even-numbered gear (i.e. 2nd or 4th) into the next lowest gear, move the shift knob up, through neutral, to the corresponding position on the top row.
- To shift from an odd-numbered gear (i.e. 3rd or 5th) into the next lowest gear, move the shift knob down to neutral, one column to the left, then down to the new position on the bottom row.
- Gradually release the clutch pedal, allowing the new, higher engine speed to match up with the vehicle's speed.
If you don't match the engine's speed properly for the lower gear, the car will probably jerk a bit. Once your skill at "matching revs" improves you can release the clutch pedal more quickly without any jerkiness.
Starting on an upslope
Decades ago, Studebaker invented and used a clutch-brake interlock mechanism called Hill-Holder™, which is currently (2004) available only on Subaru Foresters. Most Mercedes-Benz vehicles also hold the brake automatically until the clutch is at the friction point (sometimes called the biting point). Starting on a hill should be no more difficult than starting normally if a proper starting technique has been taught.
When you have stopped on a hill you must always put the parking brake on. Then, simply set the gas a slightly higher than normal RPM and bring the clutch up to bite. At this moment, let off the parking brake and the car will move up the hill. Some drivers start on hills without using the parking brake, for example by pressing the gas pedal with the edge of the foot and then quickly releasing the brake and clutch. This will result in the car rolling backwards a short distance, however, and the amount of space available behind the car must be considered. Also releasing the clutch rapidly may stall the engine.
Riding the clutch
It is possible to maintain your vehicle's position on an upslope without using the brakes by "riding the clutch" for short periods, namely using some throttle and modulating the clutch's engagement. This is not recommended for any more than a few seconds, since it causes rapid clutch wear; however it is a useful skill to learn as it enables you to control your car on a hill at low speeds.
Advanced techniques
Heel-and-toe
While decelerating, the technique of heel-and-toe shifting allows advanced drivers to maintain pressure on the brake pedal while simultaneously "blipping" the throttle to aid downshifts.
Double clutching
"Double-clutching" (also known as double-declutching in Europe) is an old technique that dates from before the days of synchromesh gear boxes. It can make downshifting (and arguably upshifting) smoother and can reduce transmission wear. It involves depressing the clutch and dropping into neutral, releasing the clutch, using throttle to match revs for the gear to be selected, depressing the clutch again and selecting the new gear. The action (which sounds more complicated than it really is) ensures that the output shaft is running at the right revs before a gear is selected hence creating smoother shifts and reducing wear on synchromesh systems. Some types of unsynchronized manual transmissions require double-clutching. These transmissions may be found in some older vehicles and race cars, as well as on large trucks, especially tractor-trailers.
Shifting without the clutch
It is also possible to shift gears without using the clutch at all, by careful throttle manipulation. When transmissions were unsynchronized this was usually the easiest method, and still works in modern cars, although it requires a lot more practice than the usual methods described above.
On cars with a freewheel, shifting without the clutch is standard procedure.