Automatic vs Manual transmission cars

Don’t worry, this post is not advice on how to live your life. Actually, on second thought, it is. Well, no, not really, it’s mostly about cars. And life.

Maybe I should start off with my main point:

Things which are “easy-to-use” often come with hidden drawbacks.

Some examples:

  • Point-and-shoot digital cameras (vs Digital SLR cameras) – Due to their larger sensors, SLR cameras can give much sharper images and more beautiful out-of-focus backgrounds. As well as much better performance in low-light situations, and more versatility with a variety of lenses. However, the compact size and low cost of point-and-shoot cameras make them a perfectly valid choice for casual photographers.
  • Automatics cars (vs manual cars) – Unlike point-and-shoot cameras, there is no valid reason (special circumstances aside) I can think of or find that justifies wanting a car with an automatic transmission – if you’re blessed with two legs.

At this point, I’m going to drop the illusion of making a general argument about “easy things” and just rant about automatic cars instead.

What’s the actual difference between auto and manual?

In a manual transmission, the connection of the road wheels to the engine is controlled by a clutch, the plates of which are mechanically locked together by friction. When the driver wants the clutch to be engaged, there is absolutely zero slippage between the plates, and absolutely zero power wasted in the clutch (neglecting friction in bearings.)

An automatic transmission car replaces the clutch with a torque converter, which is loosely defined as a couple of turbines slopping goo at each other. The engine and road wheels are never properly locked together, and power is dissipated away in the torque converter as heat. Some automatic transmissions get around this by using a lock-up clutch to prevent slip when the car is moving, but power is still wasted sloshing goo around when the car is idling, whereas a manual car lets the engine spin completely freely.

While the driver provides all of the energy required to control the clutch and change gears in a manual, an automatic transmission relies on a hydraulic pump to effect gear changes. This siphons away yet more power from the engine.

How does this make automatic cars worse?

    All cost figures on this page are given in New Zealand dollars (NZ$). It’s not a crazy currency like the Japanese Yen: at time of writing, NZ$1.00 = US$0.83 = AU$0.76 = £0.52 = €0.62

  • More expensive to buy
  • Manual transmission are mechanically simpler and smaller than automatic transmissions, so they are cheaper to build. I’m going to use the Mazda2 as an example, just because it’s the successor to the car that I currently own. The auto version costs $1400 more.

  • More expensive to fuel
  • The manual version of the Mazda2 uses 6.4 L per 100 km. Because of all of the energy wasted sloshing goo around, the auto gulps 6.8 L per 100 km. That’s over 6% more. When there was an uproar when the price of petrol went over $2.00 per litre, auto drivers were already effectively paying $2.13. The average NZ household spends just under $2000 per year on petrol, so owning an auto will cost an extra $125 every year (on top of the extra $1400 for the car.)

    The case above involves a model of car where the manual and auto versions feature the same engine. In some cases, automatic cars have to be fitted with slightly more powerful engines to overcome the inefficiencies of the automatic transmission, which only serves to further increase the costs of running the car.

  • More expensive to maintain
  • Automatic transmissions require a larger quantity of a more exotic lubricant to run, as well as hydraulic fluid (which is not present in manual transmissions.)

    I retrieved a fairly comprehensive database of car purchase, fueling and servicing costs from the NRMA. As a general rule, buying an automatic car will cost you at least $2000 more than buying an equivalent manual. Assuming that you drive 15,000 km per year, it will also cost an average of $80.16 more per year. However, if you’re on a tight budget, and wanting to spend less than $30k or $20k, then the disparity between annual running costs shoots up to $120.34 or $147.87, respectively, every single year.

    Extra purchase price Extra annual costs
    (15,000 km/yr)
    All new cars $3,126.80 $80.16/yr
    New cars < $30,000 $2,664.90 $120.34/yr
    New cars < $20,000 $2,480.60 $147.87/yr

  • Lack of control
  • You’re driving along a flat road. A little way off, the road rises up a hill. You decide to accelerate gently before reaching the hill to gain a little bit more momentum to travel over the hill without losing speed nor stressing the engine that much. Let’s see how this situation plays out with a manual and auto (and these are true stories; there is a road laid out like this near my house.)

    In the manual car, I’m in 4th gear as I approach the hill. I accelerate gently, gain a bit of speed, and make it over the hill. No gear changes, no surprises, end of story.

    In the auto car, the transmission has decided it wants to be in 3rd gear. As I press the accelerator and gain a bit of speed, the car lurches as it changes up to 4th gear, incorrectly assuming that the road will remain flat. As I reach the hill, the car realises it messed up, and lurches again as it changes back to 3rd. This all costs momentum, and I depress the accelerator a little further to make up for wasted petrol. The car then thinks I want to overtake someone, lurches as it downshifts to 2nd, and from the engine comes a screeeeeeeeam as the car starts up the hill at ridiculous speed.

    Of course, I’m exaggerating quite a bit. I’ve sort of learned to avoid this kind of situation in an auto, but this whole situation seems absurd. I can see where I’m driving, I can see the road conditions ahead. I know which gear the car should be in. Why should I have to learn how to trick the automatic car into selecting the right gears?

    The car is blind, it has no idea what’s coming. While some autos may be smarter than others, even the smartest automatic transmission in the world still has no idea whether the road is about to rise or fall, or whether I’m about to overtake someone else. As I approach a passing lane in a manual, I can downshift, even ride the clutch and build up some momentum in the engine’s flywheel, and then get a burst of acceleration at the instant that I want it. By contrast, all you can do is stamp on the accelerator in an auto, which then downshifts, revs the engine, and then starts to accelerate, costing seconds and causing frustration.

  • Can’t do hill starts or push starts
  • Imagine you’re stuck in the middle of nowhere, with no other cars around. You try to start the car – nothing happens, the battery is flat. Let’s explore the two possible scenarios, in the form of badly-drawn comics. First, the automatic:

    In short, an automatic car with a flat battery is completely helpless in isolation. You have no choice but to call for help and ask for a jump-start, and let boredom and frustration set in. The story plays out very differently with a manual transmission:

    And I’m not making this up. When we left our headlights on in a carpark, it was an exciting opportunity to finally try a push start! I pushed the car along, my friend in the car dropped the clutch in second gear, and the engine roars to life. A fun group exercise – as opposed to an hour stuck in the car bickering about who left the headlights on.

  • Potentially dangerous in hilly terrain
  • Hilly country roads require lots of braking. Excessive use of the foot brake can lead to overheating and brake fade. It’s very natural for a manual driver (without even thinking) to stay in a lower gear when travelling down a hill to make use of engine braking when travelling downhill, keeping the foot brake cool.

  • More boring
  • Every time I drive an auto, I almost fall asleep and crash.

Conclusion

An experienced auto driver is at first annoyed and frustrated by the difficulty of using a clutch. But in time, as the driver gains experience, the frustation goes away, and driving the manual becomes completely natural. Zero disadvantages remain after this brief (in the scheme of things) learning curve.

On the other hand, an experienced manual driver is at first annoyed and frustrated by the sensation that you’re not driving a car, but merely suggesting what to do to a clueless computer in the bonnet. And this never changes, because no amount of practice changes the fact that an automatic transmission will always be guessing.

Why force yourself to suffer an entire life of:

  • Lack of control
  • Vagueness
  • Frustration
  • Fear that a failed battery will delay you for hours rather than minutes (or ignorance of that fact)
  • Fear that a failed engine will leave you completely unnecessarily stuck (see the “Appendix” below), even if you have friends willing to tow you
  • Higher running costs

When the alternative is a few months of frustration followed by a life of:

  • Complete control
  • And, in short, none of the idiotic limitations listed above.

With these points in mind, there are only three reasons I can see for choosing
an auto over a manual:

  • Having only one functioning leg (although I’d personally seriously consider putting a hand-operated clutch on the steering wheel if I’m ever unfortunate enough to end up in this situation)
  • Not understanding all the pros/cons listed above
  • Or: stunning, stunning shortsightedness.

What do you think? Have I missed something? Am I wrong? If you think so, let me know in the comments below.

Appendix: Bonus material

That concludes my main rant against automatic cars. However, a few points emerged during my research which I omitted from the main rant since I wanted to keep things “short”, and these points could be construed as unlikely or pedantic.

So these aren’t intended as arguments that will make you immediately say “that’s a dealbreaker”, but are more intended to serve as further weight for the argument that automatic transmissions are just unnecessary, inelegant, and fundamentally a ridiculous solution to the problem of delivering power to a car’s wheels.

  • Being towed
  • Auto: You can put the gear selector into neutral, but without the engine running, there’s no hydraulic power to actually disengage all the gears. In other words, if your engine won’t run, then you cannot actually put the car in neutral. Thus, to be towed, the driven wheels of the car must be lifted off the road to prevent severe transmission or engine damage. So that rules out being towed out of a tight spot by your friends, because who carries a dolly with them in their car?

    Manual: Put car into neutral. Your arm actually directly engages neutral. The wheels will now spin safely, no damage to engine possible. Done.

  • Towing other things
  • In the past, many automatic transmissions were simply too weak to not be damaged by towing a trailer or another car. This doesn’t seem to apply to more recent models, though.

  • Autos are heavier
  • Using the Mazda2 again, the auto is 25 kilograms (2% of the whole car) heavier than the manual.

  • You can’t do handbrake turns in an auto
  • This is critically important stuff!

  • Behaviour in case of uncommanded acceleration
  • There have been news reports of cars accelerating without the driver pressing the accelerator pedal. Although Toyota has been cleared of wrong-doing, my mind still boggles because this whole story seems nearly impossible with a manual car.

    For those of you who have never driven a manual, it is completely different to driving an auto. When you drive a manual, your right leg makes the engine whirr, and your left leg ties the whirring to the wheels of the car, and you start moving forward. In an auto, you merely suggest movement using the accelerator, and it’s up to the car to decide how that motion gets delivered. As a manual driver, if you don’t like the way the engine is whirring, you would instinctively stamp your left foot down to cut the cord between the bad engine and wheels.

    It appears that in the majority of claimed ‘uncommanded acceleration’ cases, the drivers were mistakenly stamping on the accelerator rather than the brake. Straight away, this seems less likely in a manual, because your left leg is always on the clutch, so your sense of proprioception should give a good clue of where the brake pedal should be.

    When you want to stop in a manual, you press both the foot brake (to slow down), and the clutch (to avoid stalling.) Even in an emergency situation, this automatic connect between pressing the brake and clutch together would surely hold. If you were do mistakenly press the brake and accelerator together (i.e., both feet move right one pedal), then the brakes would win, and you’d stop (and stall) the car – no crash. If you mistakenly press the clutch and accelerator together (more likely, as there’s never any reason for your left foot to leave the clutch), then the car will coast and the engine will scream at you. You either realise what is going on and move over to the brake, or use the handbrake instead, or maybe even shift gear and engine brake instead.

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11 Comments

  1. Jack

     /  March 20, 2012

    Handbrake turns should’ve been part of the main rant!

    Reply
  2. Andrew

     /  March 21, 2012

    Just read all the posts. These are easily editorial-level rants/diagrams/even comics. How much time do you put in to each one?

    Reply
    • Robert

       /  March 21, 2012

      That’s very kind of you to say! It’s hard to say how long it takes, because I don’t do them in one hit… For this article, it was seven months from the initial brain-dump to “publication”, but it’s not like I was working on it regularly, it was only seven days that I did anything on it, and probably only a few hours in total. The comics took an extra few hours, but that’s OK because I was curious about the process by itself.

      Reply
  3. Whilst walking around Graz and examining the parked cars (~100) I found only three with automatic transmission. I have a strong suspicion the locals have been keeping a watchful eye on rs20.mine.nu

    Reply
  4. casty

     /  September 20, 2012

    AFAIK, you cannot push manual lead free gas cars either. Because the catalyst can be sunk into non-burned fuel and get damaged (or something like that).

    Reply
    • Robert

       /  September 20, 2012

      I assume you mean push-start (manual cars can be pushed around all day in neutral, the engine doesn’t even turn over). So yes, push-starting your car every day will probably start to do some damage — but doing a few times over the life of a car will do no appreciable damage, and will get you out of some otherwise very annoying situations.

      Reply
  5. Krutou

     /  April 23, 2013

    “An automatic transmission car replaces the clutch with a torque converter .. engine and road wheels are never properly locked together”

    This is false, modern automatic transmissions lock together at the highest 1-2 gears (4, 5 and/or 6).

    > Lack of control – In good ol’ 2012, there shouldn’t be any automatic cars that have dumb electronics that can’t properly address hill climb. This is further aided by presence of “shiftable automatic” transmissions.

    > Potentially dangerous in hilly terrain – Brake fade is rare in decently built modern cars. The presence of “shiftable automatic” transmissions avoids this problem altogether.

    > More boring – Subjective. Every time a moron drives a manual, they ruin their car or crash.

    > Being towed – False. Most automatics also happen to be FWD. Roll the front wheels on a 2-wheel tow trailer and call it a day. Many manual cars are RWD to be sporty. To long distance tow manual RWD cars via 2-wheel tow, you must remove the driveshaft or risk wearing out the transmission.

    > Behaviour in case of uncommanded acceleration – Because manual transmissions are immune from throttle problems. /sarcasm

    This article is over 50% uninformed bashing on automatic transmissions based on information thats either old or gathered from poorly engineered vehicles.

    Automatics are not the performance machines manuals are, but they’re not nearly as bad as this article makes them out to be.

    In modern times, manual transmissions are relegated for driving enthusiasts and racing (and really poor people). Automatic transmissions are relegated for the average consumer who doesn’t really care about driving enjoyment on during the traffic jam on the way to work.

    Reply
    • Robert

       /  May 21, 2013

      I concede the point that modern transmissions lock at higher gears. Doesn’t change the story at lower gears.

      I’ve driven a brand new car with an automatic transmission, and it still can’t see the hill before you’ve got there, obviously — so it still does stupid things when I accelerate gently before the hill. And if you’re invoking shiftable automatics and a defence for automatics… kinda makes you wonder why you’d not just use a manual in combination with the best automatic transmission on the market: your subconscious mind.

      Manual transmissions are of course not immune to throttle problems, but you completely missed my point that in a manual, a throttle problem is not at all dangerous — just cut the cord with your left foot, your engine revs like crazy but at least you’re still alive.

      And what is this rubbish that all automatics are FWD and all manuals are RWD. That’s the weakest correlation ever, and just wrong for any given make/model of car that comes in auto/manual option. And what is this about “towing long distances being damaging”? How is towing any different to coasting? How long are these distances you speak of? I’m not suggesting to tow a car from one side of the US to the other. You’ve made a compelling (albeit irrelevant) argument for preferring FWD cars. My original point that manual cars are easier to tow very much holds true despite your attempt to discredit it.

      With all that in mind, your 50% figure is laughable. Also interesting how you didn’t mention my researched cost of running info (apart from dismissing people who keep an eye on costs as “really poor people”), nor the push starting argument. Honestly, I’ve push started manual cars in tight spots, and I’ve been stranded for hours due to my friends with autos getting a flat battery. These point alone are worth a whole lot.

      Reply
  6. ExcessPhase

     /  June 8, 2013

    You forgot to mention that automatic cars also essentially prevent you from accelerating full throttle at low RPM. Usually one would expect that the automatic would exploit all available torque even at low RPM — but every automatic I saw prefers higher RPM to more (real) throttle.
    I once drove an automatic up a hill — a long climb on the freeway. The automatic was unable to keep the engine at constant speed — one could either accelerate or slow down — including an down/up shift for accelerating or decelerating. I think people in the USA are slaves to their machines — they simply think this must be like that — and of course everybody going faster than they is simply an idiot (“Why should I yield the left lane when driving 50mil/h uphill on a 65mil/h road?”).
    Still today people with powerful cars slow down on every uphill part of the highway. I think this is also partly caused by engine castration — especially honda/acura achieving max. torque at 5000 or even 7000RPM. And sometimes I think the automatic is unable to exploit torque at low RPM — it prefers higher RPM to more throttle at lower RPM.

    Then there is DSG — I really love the idea — doing double clutching on downshifts.
    But even in manual mode these cars downshift on full throttle and ignore an upshift command on full throttle — so they are essentially useless.
    Of course this can be modified — but I will not buy a car which I first have to modify to achieve something I consider sane (accelerating at low RPM with full throttle).

    Reply
  7. syaid

     /  January 13, 2014

    i swear to god that yesterday and last few month with 2 different car i almost crash it due falling asleep while driving. because i’m not connected with the car response. i’m not driving fancy car just a regular city car. this thing remind me to choose manual due long journey after work and my fatigue raise my risk to get crash if i’m not alert while driving. i took 2 test manual and auto. and i made my mind to go with manual for my own safety.

    Reply

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