Was looking at Vauxhall Zafira website and as expected the manual version is more economical than the automatic version.
However looking at peugeot 3008 website, the car comes with manual or semi-automatic transmission. It appears the semi-auto is more economical.
Are semi-auto normally more economical than manual cars? Why? To me the word semi means you can leave it in auto mode and it acts like a normal automatic car or move the lever and you can shift the gears yourself.
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Depends.
My Astra 180 auto is more economical than its manual equivalent in day-ti-day commuting.
On long trips at motorway speeds, the manual pips it by a smidgeon.
I drive an auto for the convenience factor.
With the few semiauto cars I've driven of late, actually working the gearbox has proven to be more economical than leaving it in auto, as you can select, rather than let the engine labour and then decide.
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A manual gearbox used sympathetically will I think always trump an automatic.
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I'm the most sympathetic driver I know!
As mentioned, as a day-to-dayer, round the hills and mountains, the auto edges it.
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Nowadays many automatics have a longer final gear ratio than the manual equivalents - they will usually shift into top before a typical manual gearbox user.
This is balanced to a degree with the automatic's inherently lower efficiency (esp traditional torque converter autos) and higher weight.
20yrs ago most autos had 3 gears with possibly an overdrive, now most will have 5 or more ratios - this helps a lot.
Finally, automatics can be 'tuned' to perform well in emissions/economy tests as the testers need to leave the car in 'D', whereas with manuals they must follow specific change-up points that are possibly not the most efficient for the particular vehicle.
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Yes,modern autos are as economical as manuals. I guess you get more consistent fuel consumption in autos than in manuals as in the later it can vary a lot depending on mood of driver on that very journey :)
>> Nowadays many automatics have a longer final gear ratio than the manual equivalents - they will usually shift into top before a typical manual gearbox user.
Exactly!
Last edited by: movilogo on Thu 15 Jul 10 at 08:56
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My brother has a 1.8 petrol Honda Civic 'auto' - a clutchless manual with steering wheel paddles for manual changes.
According to the official figures, it's a few tenths of an mpg more economical than the equivalent manual.
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It's usually automated manuals of whatever type that are more economical, according to the official figures anyway.
I wonder if the savings over say 5 years would be enough to cover the absurd cost of getting it put right when not if it goes wrong, add in compensation for the hell of driving the thing and you're well out of pocket.
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The Honda one is not too bad once it's up and running, but it does suffer from hesitation at roundabout and junctions, which can be unnerving.
I don't think brother is that impressed with the consumption, but he's never run a manual to know if there's much difference.
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I think the best quote i ever heard was from a Citroen salesman talking about Sensodrive before they gave it a fancier title..''it's lovely gearbox on the motorway''.
..will that be the motorway you cruise all day in top gear then?
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Most boxes that are semi-automatic are either robotised manuals, CVT or quite common now, twin-clutch. Therefore they are not a torque converter auto. They therefore do not suffer the inefficiencies of a torque converter and can keep the car near it's optimum power band.
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I thought the reason for this was the (stupid) EU fuel economy test directive. It states the speed that a car must change gear during the test if it is a manual. Therefore many cars have to change gear at not optimal revs.
Autos and semi autos get round this by being able to change gear at whatever revs they want, so they can appear to be more economical.
The EU, dont you just love em!
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I can vouch for the 1.8l Vectra auto being more economical (on motorways at least).
I have driven both the 1.8l Manual and Auto versions on the same routes.
the manual was quicker off the mark (at road junctions and roundabouts) and used less fuel around town, however on the motorway the automatic used less fuel over the same distance.
Sitting at 70mph with only 1,700rpm was really nice in the automatic....... until any hill needed to be negotiated.
I cant remember what revolutions the manual was at 70mph.
With the automatic, it was a chore to drive around town and the sport mode button was used just to get an extra few revs to pull out at junctions.
But on motorways the car was very relaxed.
I wonder how diesel automatics compare to the manual versions in real life, not the 'official' naff figures.
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>> I wonder how diesel automatics compare to the manual versions in real life, not the
>> 'official' naff figures.
>>
Not enough of them around at the smaller end of the market where I want one (slightly large Supermini size, but not next size up!)... all the manuals are far better than the autos...
Incidentally is that 1.8 engine the same one as in the Meriva? If it is I absolutely hate the thing, gutless unless revved hard and then you get low mpg... made me realise that petrols have to go a long way to beat a decent TDi... except in noise levels... but I can live with that! Having said that I will try out the TSi engine if I can find one next year, just to see if the hype is right about them...
Last edited by: hobby on Thu 15 Jul 10 at 17:57
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Computers can take off a plane and land it over a runway anywhere in the world without pilot's intervention.
So, computers can well decide when to shift gear under most circumstances.
So autos can easily achieve better economy. :)
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My Fiancée’s Citroen C4 is a auto and its cheaper to tax (IIRC) than its manual equivalent as apparently it throws out less Co2
“it” decides according to the instruction manual that it changes gear to maximise economy and reduce emissions
Therefore I would say that it is more economical.
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Computers can take off a plane and land it over a runway anywhere in the world without pilot's intervention----
Yeah right --- would you fly on a plane with a computer instead of a pilot....imagine the take off announcement as you trundle down the runway
' Ladies and gentlemen today you are flying on the first plane ever piloted purely by computer . We would like to assure you that everthing is completely under control and nothing can go wrong -- click
can go wrong --click
can go wrong --click
can go wrong --click........................'
Last edited by: retpocileh on Fri 16 Jul 10 at 11:04
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>> Computers can take off a plane and land it over a runway anywhere in the
>> world without pilot's intervention----
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>> Yeah right --- would you fly on a plane with a computer instead of a
>> pilot....imagine the take off announcement as you trundle down the runway
>>
>>
Its true, a Pilot is only there if something goes wrong - Modern Aircraft can take off and land pretty much by itself
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nothing new, pilot's of the 'ground gripper' DeHavilland Trident aircraft regularly put autopilot on just after taking off (less than 50 feet off the ground) and flew auto pilot the whole route to the destination.
And that as you can guess was a 'few' years ago
Last edited by: diddy1234 on Fri 16 Jul 10 at 12:14
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...a Pilot is only there if something goes wrong...
I'll take that as a cue to tell my BA Super Shuttle landing story.
I was on an internal flight from Manchester and it was just as we came into land at Heathrow.
We were quite near the ground when the pilot gave it full beans and up we climbed again.
Everyone looked at each other, as you do.
Pilot then announces via the intercom: "Sorry about that, ladies and gentleman.
"The instruments say there is a fault with the landing gear, but we think it's alright.
"What we are going to do is fly past the control tower, so they can have a look."
Which is what he did.
We then came in again, and this time landed normally.
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>> Pilot then announces via the intercom: "Sorry about that, ladies and gentleman.
Flying down to Bristol from Newcastle, the original pilot didn’t turn up
We where sat in our seats waiting for one to turn up, when a pilot boarded, and said to the stewardess “where are we going then”?
I like to think that he just punched in “Bristol” in the sat nav, and pressed “go” but I know (or at least like to) that the Auto pilot is a little more advanced than that
It was a few days later a work collegue who is a qualified pilot (of some description) told me all about planes abilty to fly them selves, and how they work.
Last edited by: Redviper on Fri 16 Jul 10 at 12:55
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en.wikipedia.org/wiki/US_Airways_Flight_1549
At least in this case, I'd be opting for the human pilot ;-)
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In automatics (incl. conventional ones), you can shift gears manually if you wish so :)
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>>
>> I'll take that as a cue to tell my BA Super Shuttle landing story.
>>
I was once delayed at Thesalonki while and Olympic 737 did various low passes and touch & goes before landing, we watched it from the departure lounge, quite scary, it eventually land safely.
Also ...
... approx a month ago I was landing at Copenhagen and on final approach, shortly before touch down the pilot gave it some welly and climbed away banking to the left at the same time, I was on the right hand side and looked out of the window and could see a plane on the runway, lucky it was not dark, foggy etc. The flight crew apologised explaining that the runway was not clear ...
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...Olympic 737 did various low passes...
I think I was in a small Boeing which was newish at the time.
Might have been a 737 or a 757.
BA also had one or two old crates on the internal routes - I remember one which juddered so much with the strain of taking off, a couple of the overhead lockers burst open.
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>A manual gearbox used sympathetically will I think always trump an automatic.
That would have been true 10 years ago but no longer. ECU controlled-engines and gearboxes know far better than us humans what the best ratio is at any given time for optimum economy. Using a manual gearbox sympathetically is also, sadly, a dying art.
Mercedes claim that models fitted with their 7G-Tronic torque converter auto box are quicker than their manual equivalents but save over 0.5L of fuel per 100km.
I think that it won't be long before most mainstream cars come with auto boxes.
Kevin...
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>> Mercedes claim that models fitted with their 7G-Tronic torque converter auto box are quicker than
>> their manual equivalents but save over 0.5L of fuel per 100km.
Should be quite economical while it's in for it's 14th software update to stop the first/second lurching, not long lived by all accounts either.
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ECU controlled-engines and gearboxes
>> know far better than us humans what the best ratio is at any given time
>> for optimum economy.
Yes, Even if you put my partners C4 into "manual" it still takes over if it thinks you are doing it wrong, and then puts the car back into auto mode again
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Are some auto more economical than manual? - Ian (Cape Town)
