automatic gearboxes vs. manual ones

Fred · 2009-05-20T19:04:13+00:00

Hello,I hope this isn't a flame or a FAQ but what are the pros and cons ofautomatic and manual gearboxes? I've only ever driven manual carsbefore. I've just been on holiday and rented a car which wasautomatic. I get the impression that Britain is the only county thatdrives manual cars; is that true? Why?I found the automatic a pleasure to drive. The only problem I had wasthat if I went up along a motorway slip road I would put my foot downto accelerate to motorway speed and the gearbox would drop a couple ofgears and rev loudly. I really wanted it to stay in the gear it was inand accelerate. If I approached a hill I would press the gas tocounter the gradient and the same thing happened. I am used to drivinga sluggish diesel, so perhaps I was heavy footed? Was it my fault oris this a "feature" of an automatic gearbox to do this?How should they be driven properly? I wasn't given much instruction!I have spoken to some people who think they are "something else to gowrong". Is that true? Are they prone to break? I guess they areexpensive to repair?What is the life of an auto gearbox? Is it better than a manualgearbox and clutch? I wonder whether the reverse is true: is a manualmore likely to wear out or fail because it can be driven badly,whereas does an auto change more smoothly and gently?I see that autos have a slightly lower fuel economy. Why is that? Isthe gearbox/gear changing not as efficient or is it that the autogearbox is much heavier than a manual and weighs the car down?Finally, is there such a thing as a diesel automatic? (Thinking of changing my car and weighing up the gearbox options)TIA

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BobC 17 years ago

Not just UK, but the Why is the big question. I have a company car, so no choice but if I did have one it would be auto. Wife has had several small autos. Won't drive my car 'cos it's not. I think autos are brilliant. Why doesn't everyone have them? Slight increase in fuel consumption?

The US is thougth of as being all auto but I was suprised when I first went there how many manuals there were. Far more than I expected. When renting I had to specify I wanted auto, default was manual.

The king of auto is Australia. Virtually unheard of for a car to have manual. If you want a manual you get a "Ute" (translates to 4x4 or SUV). If you buy a car manual is an optional extra that you'll pay more for, opposite way round to here.

You get used to it with time. A rental period probably isn't long enough. You get to be able to predict when it's going to change and it start to do it when you want.

The only time I've found an auto a pain was driving up and down mountains in Tasmania. Car was a 5 speed auto and it went up and down the box like a yoyo as I went round the hairpin bends. Solution: manually select the gears. On that box you could select any of the five manually.

Never had one fail yet and have had some pretty old grotty ones, eg a Micra K10 which cost =A390. Box was perfect and still was when I sold a year later.

You have a fluid flywheel which is slipping all the time. That generates heat which is a loss. However, all the autos we've had lock the fluid flywheel when up to a certain speed, eg had three Micra K10s and they all locked at 42mph. Locked up... no slip... no loss in economy. So on the motorway consumption OK, round town not so good.

I believe so.

I'd go for auto, but it's personal. I guess plenty of other will tell you why you shouldn't!

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Adrian 17 years ago

BobC gurgled happily, sounding much like they were saying:

No, it doesn't. A ute is a pickup.

Riiiiight.

No, you don't. You have a torque converter. Fluid Flywheels were one of Fred Lanchester's many inventions, and went together with pre-selector gearboxes in pre-war Daimlers.

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Kostas Kavoussanakis 17 years ago

All the time. I don't necessary change down, but count on the gear to slow down. Esp. true downhill.

Kostas p.s.: Thanks for the answer Duncan and Adrian!

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Chris Whelan 17 years ago

My driving is a bit old-school, so probably more than is the norm by today's standards!

Imagine you accelerate briskly from a set of lights, approaching a roundabout. Whilst accelerating, 2nd gear is held. You lift, and brake briefly as you enter the roundabout. When you start to accelerate in the roundabout, the box has changed up to 3rd. You press harder, and in the middle of the corner, just where you don't want a gear shift, it drops back to 2nd.

I hadn't driven a modern auto for a while, and thought that they might suit me better now, but a couple of goes in my son's (Y-reg) BMW soon convinced me that I just don't get on with them.

I think they are something you either love or hate; I'm in the latter group!

Chris

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Dave Plowman (News) 17 years ago

Used on some autos too. The GM hydramatic as used by Rolls in the '50s was a four speed with fluid flywheel as were M-B autos of that time. The original Mini also.

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Chris Bartram 17 years ago

Modern conventional autos (and IME even more so DSG) are much better at doing changes properly. The worst I ever drove was a 1986/7 Mk4 Escort. Practically guaranteed to be in the wrong gear 50% of the time.

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Chris Whelan 17 years ago

[...]

Oh, they do them properly; just not when *I* want them to!

Actually, my brother-in-law has had a succession of Passat autos. They have such a jerky change that my elderly, non-driving mother used to think he was a really poor driver. She always complained of neck pain after travelling in his car!

Chris

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SteveH 17 years ago

You need to try a 1970s vintage VW auto with a gutless 1.5 engine in a MkI Golf Cabrio.

I don't think there was any such thing as a 'right' gear in that.

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SteveH 17 years ago

Driving technique.

The Alfa Sillyspeed (robotised manual) is often described as jerky. In fact, it is when Mrs H drives it - but you can easily adjust your driving technique to smooth things out.

The trouble with autos is that most people believe is that you can 'plant your foot and forget' - you get the best out of an auto by learning how to modulate your right foot to get the best out of them.

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Chris Whelan 17 years ago

[...]

Precisely the sort of reason why I fail to see the point of them.

If you have to learn a particular technique, you might as well learn how to drive a manual properly.

Chris

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SteveH 17 years ago

Hmmmm.

Maybe.

For me, an auto is a god send as I have dodgy knees due to sporting injuries suffered in my late teens.

Driving a manual in traffic or the hills / mountains is a very painful experience.

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Conor 17 years ago

If it was like that when he drove an auto, it'd be the same when he drove a manual.

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Dave Plowman (News) 17 years ago

Then it's poorly designed. Like most of the early SMG type transmissions. My SD1 Rover is 25 years old - and has a GM 3 speed box. You don't need to 'modulate' your right foot for a smooth change.

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Dave Plowman (News) 17 years ago

It's simply not true with a decent auto in good condition.

Like I keep on saying many base their opinions about autos on some worn out clunker.

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Duncan Wood 17 years ago

& on 2 hrs driving experience, drive an auto like you'd drive a manual & it'll be crap, drive a mini like you'd drive a Capri & you'l end up in a ditch.

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Duncan Wood 17 years ago

Yup, if you want perfect road feel then nothing compares with riding a fixy but it's not a sensble ay of getting from London to Edinburgh.

Ah, now in traffic I'd agree, but the right (wrong) inclineis perfect for showing up most automatics.

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Chris Whelan 17 years ago

[...]

Newest one I've driven is my son's Y-reg Beemer; have they really improved that much in the last 8 years?

Chris

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Dave Plowman (News) 17 years ago

Probably the same series box as the ZF 5 speed in my older one. What was wrong with it? I've come across a couple that have a rough 1-2 change at low speed - but that's a fault. Otherwise it should be pretty good. But yes, they have improved since then in all sorts of ways.

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Conor 17 years ago

If its been poorly maintained, it'll be a bag of s*it. Many people don't bother changing the oil filters in them for example.

A fair bit but nothing to do with the fault on the gearbox you drove.

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Chris Whelan 17 years ago

It's not been poorly maintained. It's not a bag of s*it. Oh, and there's no replaceable filter in the box.

I wasn't complaining about a fault, or anything specific about this gearbox. I just haven't driven any auto yet that would make me say "That works well; I'll have to get one."

Chris

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