Manual vs Automatic Transmissions

An often debated topic in the automotive world, and one that I have a clear stand on: drive an automatic if that’s what your into, drive a manual if that’s what you’re into and that’s that. But, for those of us who love the control and intimacy that you get with a manual gear box (not sequential, dual clutch, paddle shifter bullshit but a real manually shifted transmission with a clutch, shift linkage and an actual shifter/shift knob), it seems that our days are numbered 😦 and thats a damn shame as no other transmission set up (imo) can provide the engagement that three pedals and a shifter can.

Look at BMW, Ferrari, Lamborghini, Mercedes, and even Honda and Mitsubishi. They are all turning to paddle shifters or super high-tech and fast automatic transmissions. I’m all for progression but not at the expense of being in much more control of your car. Now I’m sure some of these fancy transmissions are a lot faster like the dual-clutch in the Nissan GT-R or Mitsubishi EVO but, simply put, it’s just not as fun whether its faster or not.

While perusing, I found this very informative, wish I could provide proper reference but it was just a guy replying to the question. I’m in no a way a licensed mechanic but I do know a few things but this little excerpt definitely taught me more and made me love manuals even more :).

Manual transmissions generally offer better fuel economy than automatic torque converter transmissions; however the disparity has been somewhat offset with the introduction of locking torque converters on automatic transmissions.[3] 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.[4] Manual transmissions do not require active cooling and generally weigh less than comparable automatics.[3] The manual transmission couples the engine to the transmission with a rigid clutch instead of a torque converter which slips by nature. Manual transmissions also lack the parasitic power consumption of the automatic transmission’s hydraulic pump. Additionally, they require less maintenance and are easier to repair due to the fact that they have fewer moving parts and are, mechanically, much simpler than automatic transmissions. When properly operated by an experienced driver, manual transmissions also tend to last longer than automatic transmissions.

Manual transmissions also generally offer a higher selection of gear ratios. Many vehicles offer a 5-speed or 6-speed manual, whereas the automatic option would typically be a 4-speed. The higher selection of gears allowed for more uses of the engine’s power band, allowing for higher fuel economy and power output. This is generally due to the space available inside of a manual transmission versus an automatic since the latter requires extra components for self-shifting, such as torque converters and pumps. Automatic transmissions are now adding more speeds as the technology matures. ZF currently makes an 8-Speed automatic transmission, which is used on the Rolls Royce Ghost and the Bentley Mulsanne. The automatic transmission in the Nissan 370Z also has 7 speeds.

Manual transmissions are more efficient than conventional automatics and belt-driven continuously-variable transmissions.[5] The driver has more direct control over the car with a manual than with an automatic, which can be employed by an experienced, knowledgeable driver who knows the correct procedure for executing a driving maneuver, and wants the vehicle to realize his or her intentions exactly and instantly. When starting forward, for example, the driver can control how much torque goes to the tires, which is useful on slippery surfaces such as ice, snow or mud. This can be done with clutch finesse, or by starting in second gear instead of first. An engine coupled with a manual transmission can often be started by the method of push starting. This is particularly useful if the starter is inoperable or defunct or the battery has drained below operable voltage. Likewise, a vehicle with a manual transmission and no clutch/starter interlock switch can be moved, if necessary, by cranking the starter while in gear. This is useful when the vehicle will not start, but must be immediately moved e.g. off the road in the event of a breakdown, if the vehicle has stalled on a railway crossing, or in extreme off-roading cases such as an engine that has stalled in deep water.

Currently only fully manual transmissions allow the driver to fully exploit the engine power at low to medium engine speeds. This is due to the fact that even automatic transmissions which provide some manual mode (e.g. tiptronic or DSG), use a throttle kickdown switch, which forces a downshift on full throttle and causes the gearbox to ignore a user command to upshift on full throttle. This is especially notable on uphill roads, where cars with automatic transmission need to slow down to avoid downshifts, whereas cars with manual transmission and identical or lower engine power are still able to maintain their speed.

In contrast to most manual gearboxes, most automatic transmissions have a free-wheel-clutch. This means that the engine does not slow down the car when the driver steps off the throttle, also known as engine braking. This leads to more usage of the brakes in cars with automatic transmissions. (the commodity Nissan’s or Honda’s automatic gearboxes disables the free wheel operation completely if the driver has selected a gear position other than “D” – either “1″, “2″, or “D with overdrive off”. This works by blocking the free-wheel sprag using a multi-disk clutch called the “overrun clutch”)

The smoothness and correct timing of gear shifts are wholly dependent on the driver’s experience and skill. If an inexperienced driver selects the wrong gear by mistake, she/he can do damage to the engine or transmission.

Attempting to select reverse while the vehicle is moving forward causes severe gear wear (except in transmissions with synchromesh on the reverse gear). Most manual transmissions have a gate that locks out reverse directly from 5th gear however, to help prevent this. In order to engage reverse from 5th, the shift lever has to be moved to the center position between 2nd and 3rd, then back over and into reverse. Many newer six-speed manual transmissions have a collar under the shift knob which must be lifted to engage reverse to also help prevent this.

Choosing too low of a gear with the car moving at speed can over-rev and damage the engine. There is a learning curve with a manual transmission; the driver must develop a feel for properly engaging the clutch, especially when starting forward on a steep road or when parking on an incline.

Some automatic transmissions can shift ratios faster than a manual gear change can be accomplished, due to the time required for the average driver to push the clutch pedal to the floor and move the gearstick from one position to another. This is especially true in regards to dual clutch transmissions, which are specialized computer-controlled manual transmissions. Even though some automatic transmissions and semi-automatic transmissions can shift faster, many purists still prefer a regular manual transmission.

Manual transmissions place a slightly greater workload on the driver in heavy traffic situations, when the driver must often operate the clutch pedal. In comparison, automatic transmissions merely require moving the foot from the accelerator pedal to the brake pedal, and vice versa. Manual transmissions require the driver to remove one hand periodically from the steering wheel while the vehicle is in motion.”

Thanks smart man! I didn’t blindly take the information as correct either, I also confirmed a few things here and there just to make sure it wasn’t just incorrect rambling lol.

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