Manual vs Automatic

safety
transmissions

#1


Posts: 2



manual vs. automatic transmission

#317780 - 01/14/06 04:50 PM

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I need a concsise summary of the pros and cons of manual and automatic transmission. I’m about to purchase a new Honda Civic and I’m wondering if there is a particular advantage, especially in terms of safety, in one or the other type of transmission. Thanks for any input.





This post has been moved to the new Car Talk Discussion Area, by a Car Talk Lackey. The original poster is Setauket.




#2

Automatic is safer if either arm is injured and you can’t shift or steer well. If your left knee is injured, it’s no fun to use the clutch. All things being equal, nothing is equal. I haven’t had any hand bruises since having automatic only. Or I haven’t noticed that I had the injury. I used to get those three times a year. Discouraging.


#3

Manuals promote more driver involvement so you’re more likely to be more focused if/when imminent danger occures. This allows you to pickup on the danger faster and react quicker.

Some manuals get better gas milage than their automatic counterparts. A manual transmission weighs less than an automatic and a clutch is always “locked up” as long as you’re not pressing the clutch pedal. An automatic utilizes a fluid coupling (the Torque Converter) which results in energy lost to friction and slippage/spin, and also the fluid has to be pumped and while I’ve never fully understood the pumping mechanisim of the automatic transmission I am under the impression that it is driven directly by the engine. That takes energy also.

Also, and this is most important to most manual transmission drivers: Manuals are more fun!

If you don’t care for the additional level of involvement and the fuel milage difference (which will be only a couple MPG) isn’t worth it to you, the go with the automatic.

If you have never driven stick, it will take you a few days to acclimate to your new car, which may seem rather frustrating. You will also want to have a passenger who is familliare with stick go with you on your first drive or few to ensure that you’re not killing the clutch. Once acclimated, you will get better quickly, and shifting should become second nature to you within a month or so.

Happy driving!

-Matt


#4

RE: "Manuals promote more driver involvement so you’re more likely to be more focused if/when imminent danger occures. "

Most drivers with more than a few hours’ experience with a manual transmission do not have to pay more attention. The car tells them when it’s time to shift, but the part of the brain that is monitoring the engine isn’t the part that is paying attention to dangerous road conditions or situations.

I don’t drive AT cars very often, so I don’t know if AT drivers are really unaware of what’s happening with their cars. I know that some drivers are paying attention to the road and some aren’t, but I don’t think it matters if they have an AT or MT.

I simply have no interest in any car that doesn’t have a MT. Cheaper to buy, cheaper to maintain, cheaper to replace, and more fun to boot.


#5

Automatics have lock-up torque converters, so once the vehicle speed is over 30-35 MPH the engine and transmission are solidly coupled, just like a manual.


#6

Interesting theory. I’d sure like to see data on this theory. I have found the opposite to be true. While I agree that with practice, shifting a manual gets more routine, it does indeed take SOME attention, so I find it hard to believe that driving an AT actually reduces attention to the road.

I agree with person who says attention depends upon individual.

I drive an automatic, because I have large feet. it is much more work, and for me takes a lot of attention to move my feet on modern foot controls without getting them tangled up.

You don’t know fear until you are in the midst of a fast stop and your feet are tangled up in the pedals, or maybe your foot is on both throttle and the brake! Never again.

So no one wastes time on the usual criticisms, I have had one wreck in the last 39 years, and I was sitting still at the time. So was the car behind me, but the next one…


#7

I have always felt that Automatics should have been limited to the disabled. Manuals last longer, get better gas millage, can’t be driven by someone so drunk they are sure to get in a wreck, and they keep the driver more tuned into what s/he is doing.


#8

I disagree with your assertion that

Most drivers with more than a few hours’ experience with a manual transmission do not have to pay more attention.

Even if it is a background task, I find that I am much more aware of what my car is doing in terms of acceleration and coasting when I drive a stick. Because the transmission does not take care of itself, I tend to pay more attention to traffic conditions and anticipate what is happening. Even though I recently switched from an MT to an AT at my wife’s request, I still tend to shift the lever to put the car into the gear I desire; most AT drivers pay no attention to this, and lose, for instance, the benefit of engine braking.


#9

Manuals last longer, but require clutch replacements that often cost as much as an AT rebuild

get better gas millage, actually, mileage, but that isn’t even true taking into account modern electronic transmission controls.

can’t be driven by someone so drunk they are sure to get in a wreck, yeah, right (that’s BS)

and they keep the driver more tuned into what s/he is doing… well at least we agree on that point.

In the U.S., it’s supply and demand. People demand ATs, so that’s what they get.


#10

I like driving a manual, but I disagree that MT drivers are “more attuned” to what’s going on on the road, and are less likely to get into accidents. If that were true, insurance crash data would support the claim. It’s also totally bogus to claim that severely drunk people can’t get a manual going (or going fast enough) to cause crashes.

I also disagree with the contention that you’ll have lower repair costs with a manual transmission. If you drive your car long enough, you are guaranteed to have to replace the clutch in a MT car. However there are many AT cars out there now that, with the recommended maintenance, will last until you retire the car for other reasons. Of course there are many AT cars with a known history of transmission problems too, and an AT rebuild almost always costs more than a clutch replacement.

Russ


#11

Today’s automatic transmissions are good enough that which is better for you is just a matter of personal preference. If properly driven and maintained, both should last a very long time.

The major difference between them is the learning curve. With an automatic, you can just get in and drive. In contrast, it takes a while to learn to drive a manual transmission smoothly. During the learning period the mechanics of operating the clutch and gear shift are something of a distraction. In time, shifting will become second nature.

The weakest part of a manual transmission is the clutch. What kills a clutch is slipping it as you start from a stop and when you shift gears. If you minimize slipping as you start out and accurately match engine speed as you shift gears, the clutch should last a very long time. We have two daily drivers with manual transmissions. One is 9 years old with 168k miles. The other is 23 years old with 184k miles. Both are still on their original clutches.

Today, there is no practical reason for preferring a manual transmission over an automatic. However, a manual transmission is more fun for those to whom driving is like a hobby rather than just another domestic chore. A car person derives the same satisfaction and sense of accomplishment from driving well that an athlete does from playing a sport well. If this doesn’t resonate with you, you will probably be happier with an automatic.


#12

There seemed to be a belief in my Dad’s generation that Real Men drove manual transmissions while women and girlie-men preferred automatics.

However, with the landing of VW bugs and the earliest Japanese imports, it appeared to my generation that any car sold with a stick shift was too cheap or under-powered to be equipped with an automatic.

There was the argument that automatics were considered less dependable than manuals, but, as time went by, the stats seem to suggest the opposite, though it might be due to more inexperienced drivers burning up clutches.


#13

All of my cars have a manual simply because I find it more enjoyable. An added bonus is that my cars are less likely to be stolen, because most people don’t even know how to drive a manual anymore!


#14

With MT, you can be a snob and pretend that you’re more skilled - just like a race car driver - and race through city streets like a jerk. If that doesn’t hold up, you can justify a MT with some nonsense like MPG, involvement, or cheaper maintenance.

-Skill, any monkey can learn how to drive a MT.
-MPG, doesn’t save much these days.
-Involvement, how involved do you want to be in rush-hour traffic?
-Maintenance, if you can’t afford to fix a car - get a better job.

Everyday life is about comfort and being able to afford to not have to do mundane things like shifting. Keep MT on your sports car and drive for pleasure in your leisure time.


#15

“-Skill, any monkey can learn how to drive a MT.”

It takes years to master completely. There’s a certain point in my commute where I make two heel-toe downshifts in quick succession while turning onto a desolate side street. Operating three pedals with two feet, all at the same time, is entertaining and requires real skill.

“-Involvement, how involved do you want to be in rush-hour traffic?”

Very. I’m bored otherwise. I don’t have to face constant stop/go traffic, so there is no downside for me.

“-Maintenance, if you can’t afford to fix a car - get a better job.”

That’s a silly argument. I like low maintenance cars, and it has little to do with my finances. A clutch change is an easy and satisfying job to do in my driveway. An automatic transmission swap/rebuild is not.

“Everyday life is about comfort and being able to afford to not have to do mundane things like shifting. Keep MT on your sports car and drive for pleasure in your leisure time.”

My everyday life is about enjoying it. If you’re not into cars, fine, but don’t tell me what life is about!


#16

In weekend, around-town driving, the increased “involvement” of a manual is a good thing.

In demanding conditions (ex. severe rainstorms, or a fast, crowded big-city interstate) it can be a distraction.

On long drives, it can increase driver fatigue and actually reduce situational awareness


#17

If you drive your manual like it was an automatic, then yes you will get approximately the same gas mileage. In my M3, I get ~22 MPG average driving normally. Using exclusive MT techniques though, it’s no problem to get 25 MPG, and I can get up to 30 MPG average if I try.

When you’re going over a hill, you coast down the hill with the clutch disengaged in a MT - you’re idling at about 600RPM, so you’re using almost no gas, and yet you’re gaining speed. An automatic would be going much higher RPMs, and would probably be maintaining or even losing speed since there’s the added friction of the engine attached to the drivetrain slowing everything down.

Also, drag starts are not possible in an automatic. In a manual, you rev up to 3800 RPM (on my car, that’s the spot with maximum torque, your car may be different), and drop it into first for a rocket off the line. In an automatic, it would be too slow going into 1st to get a good start.

Also, as someone already mentioned, heel-toeing is not possible in an automatic. So when you’re driving around a corner at the limits of your tire’s adhesion, your automatic transmission may suddenly decide to downshift and that little jolt will break the grip and you’ll start to slide. This causes you to unnecessarily drive well under the car’s limits because you don’t know when that automatic transmission will decide to switch.

Another point: sometimes you want to drive around in high gear (low power, but high mileage), and sometimes you want to race (high power, low mileage). Since the automatic transmission does not see the road ahead, and does not know what you want to do, it is inherently less efficient than you are.

Lastly, automatic transmissions are heavier than manuals.

These reasons are why no serious sportscar has an automatic transmission (go to a racetrack and see how many automatics are there). I know the Mercedes McLaren SLR has an AT option, but if you really wanted to take it to the track, you would stick with the MT version.

Now, everyday driving convenience or cost is


#18

Y’all are forgetting one key thing in all these posts. In the UK; there are few AT so if one wants to rent a car there; one needs to learn how to drive one before on goes. Since the British / Irish drive on the correct side of the road; there is going to be alot of problems for someone to learn to drive a MT and drive on the correct side of the road so one should learn ahead of time (before they holiday in the UK / Ireland)

What about the rest of Europe? Arent cars still mostly MT ?


#19

Yes, most of the rental cars in Europe are manual, and a lot of them are diesel. I drove a Citroen mini-van through France and Italy last September. It was manual and diesel. Since I drive a manual all the time at home this was no problem. Cars with automatics are available, but the rental rate is higher.

Since I rented in France the steering-wheel was on the left side of the car as we Americans are used to. We visited England, but waited until we got to France for the car because I didn’t want to drive a right-hand drive car in France and Italy where they drive on the right as we do.


#20

I drove exclusively manuals for some thirty years. This last decade I’ve been driving both, the last three years being all automatic. No disrespect to anyone, but this stuff about a manual keeping you more alert…it’s balogna. Good driving habits are formed early in life and stay with you forever no matter what you drive.

Automatics cost more up front, $800 in the case of my tC. Automatics require periodic servicing, manuals an occasional clutch assembly. Both are reliable if properly driven and maintained. Because of the up-front cost I’d have to say manuals are typically more expensive overall.

Properly driven, a clutch can last a long time. The only one I ever wore out lasted 295,000 miles.

In my humble opinion, the only real criterion should be which one you enjoy more. You’re going to spend a lot of miles behind the wheel…you may as well enjoy them. I do.