Auto Gearbox have worse fuel efficiency? Whose fault?

[Nf0rc3r]

Auto gearboxes has advanced a lot since its beginning. Some in fact have same or even better fuel efficiency ratings then their manual counterparts.

But when put to practical use, auto gearboxes always have worse fuel efficiencies den the manual counterpart. Why?

 

I feel its the driver. Driving a manual forces the driver to look further ahead, brake less, anticipate lights better because of the troublesome need to change gear if they do not pay attention.

Auto drivers don't really has this extra incentive to keep a lookout for situations like these and thus step on the accelerator and brakes more often.

 

Watcha think?

[Bicolor]

Watching lots of friends and relatives drive, I noticed that many don't really know how to, or don't bother to, make use of optimal shifting of gears, holding down the accelerator at roughly the same kind of pressure and thus delaying upshifts unnecessarily. I'm a relative beginner with auto cars, so I might not be completely right, but I've always heard from a friend who is very particular about getting good FC that better fuel economy is gained by enabling upshifts when the time is right, by going light-footed and lifting off whenever you feel the speed and RPM is just right for the next gear. And from my brief experience driving an automatic car last week, it appears to be true. Looking ahead and braking early, gently and steadily also results in better FC - I do notice that most local drivers tend to brake heavily quite late.

 

My father usually prefers to rent auto cars, and his method is usually flooring the accelerator till he reaches the desired speed. Probably no coincidence that he always complains about the cars he gets having lousy FC.

 

Of course in a manual car one has more control of gears and engine braking which can allow one to reach a better FC more easily, but I believe driving habits do play a big part too. The 2.5l auto car I rented recently (Toyota Mark X) gave me the third best FC of any car I've driven so far.

Edited May 30, 2010 by Bicolor

[Lammy84]

total nonsense.

Go check up on how autoboxes work, they have poorer FC ALWAYS, where in the world did u read where an auto box has a better FC than a manual tranny? Unless you are talking about those auto boxes like DSC where they have a automated manual clutch.

 

Tradditional torque converter clutch have poorer FC simply because they are less efficient than their manual counterpart. Some of the energy is generated by the engine is lost through the transmission, auto boxes simply lose more of the energy as compared to manual ones. Take a 200 horsepower engine and mate it to a torque box and a manual, the resulting wheelhorse power is always lower in the torque box.

[Watwheels]

A lot of factors like distance, driving pattern, tires, tire pressure, type of car(SUV or sedan), power to weight, etc and gearbox(of course) plays a part on FC. Driving in sgp hardly make much significance on FC regardless of whatever gearbox or how the driver drives. So why the blame game? I dun see the point hence I voted "Dun Care".

[Pisces69]

Auto gearboxes has advanced a lot since its beginning. Some in fact have same or even better fuel efficiency ratings then their manual counterparts.

But when put to practical use, auto gearboxes always have worse fuel efficiencies den the manual counterpart. Why?

 

I feel its the driver. Driving a manual forces the driver to look further ahead, brake less, anticipate lights better because of the troublesome need to change gear if they do not pay attention.

Auto drivers don't really has this extra incentive to keep a lookout for situations like these and thus step on the accelerator and brakes more often.

 

Watcha think?

==============

 

Autoboxes lose some of the power due to the "slip" in the way the autobox functions.

 

With the present "lock-up" in autos, they now have much better FC than b4 & can even rival a manual.

 

An auto can get better FC only if the manual driver constantly over revs his engine & ends us wasting fuel. Usually if a manual is driven properly it sud get better than the auto counterpart but nowadays the difference is very very slight only.

 

[Ithunk]

driver....driver has to haf a super light foot

[SimonTan]

Auto CVT type, got better economy than manual or not?

 

I don care about fuel economy because the difference is few hundreds at most.

The ease to brake, swerve, power up is priceless for auto cars.

Taxi drivers used to drive manual, so their braking and swerving stunts on the road was limited!

But with most taixs auto gears now, I see lots of dangeouus stunts,last lane change, e-brake stunts, etc.

 

The road has become more dangerous lately. All thanks to auto gears. Oh not forgetting auto gears licence are dairy to get as the fear or engine die on slope and parking are vertually not a worrying point now!

[Lammy84]

Auto CVT type, got better economy than manual or not?

 

I don care about fuel economy because the difference is few hundreds at most.

The ease to brake, swerve, power up is priceless for auto cars.

Taxi drivers used to drive manual, so their braking and swerving stunts on the road was limited!

But with most taixs auto gears now, I see lots of dangeouus stunts,last lane change, e-brake stunts, etc.

 

The road has become more dangerous lately. All thanks to auto gears. Oh not forgetting auto gears licence are dairy to get as the fear or engine die on slope and parking are vertually not a worrying point now!

 

you really dont know about cars right?? take a tradditional auto and manual, most people without retarded hand eye coordination can do it better in the manual than auto..

[Suv8]

total nonsense.

Go check up on how autoboxes work, they have poorer FC ALWAYS, where in the world did u read where an auto box has a better FC than a manual tranny? Unless you are talking about those auto boxes like DSC where they have a automated manual clutch.

 

Tradditional torque converter clutch have poorer FC simply because they are less efficient than their manual counterpart. Some of the energy is generated by the engine is lost through the transmission, auto boxes simply lose more of the energy as compared to manual ones. Take a 200 horsepower engine and mate it to a torque box and a manual, the resulting wheelhorse power is always lower in the torque box.

 

CVT is best. Infinitely variable gearing linked by computer to engine management system. 6 or 7 speed autoboxes tries to imitate that by providing better gearing to economise fuel..

 

e.g old Jazz CVT gives better FC than latest Jazz using a 5-speed auto.

 

but these days who would drive a manual? 10% of buyers p.m or p.a ?

 

[Lammy84]

==============

 

Autoboxes lose some of the power due to the "slip" in the way the autobox functions.

 

With the present "lock-up" in autos, they now have much better FC than b4 & can even rival a manual.

 

An auto can get better FC only if the manual driver constantly over revs his engine & ends us wasting fuel. Usually if a manual is driven properly it sud get better than the auto counterpart but nowadays the difference is very very slight only.

 

lock up or no lock up, its the moving off/slowing down that kills fuel economy and autos dont "lock up" until higher revs typically, unless u are talking about manual boxes with automated clutches.

[The_Bear]

total nonsense.

Go check up on how autoboxes work, they have poorer FC ALWAYS, where in the world did u read where an auto box has a better FC than a manual tranny? Unless you are talking about those auto boxes like DSC where they have a automated manual clutch.

 

Tradditional torque converter clutch have poorer FC simply because they are less efficient than their manual counterpart. Some of the energy is generated by the engine is lost through the transmission, auto boxes simply lose more of the energy as compared to manual ones. Take a 200 horsepower engine and mate it to a torque box and a manual, the resulting wheelhorse power is always lower in the torque box.

 

You are talking about the mechical cause and he is talking about the human effect. So he could not be total nonsense unless...

[Pisces69]

lock up or no lock up, its the moving off/slowing down that kills fuel economy and autos dont "lock up" until higher revs typically, unless u are talking about manual boxes with automated clutches.

==========

 

Thats why I say autos have almost as good FC as a manual. It still loses abit of economy until it locks-up.

 

But for those drivers who over-rev their manuals, then their FC wil b worse.

 

[Lammy84]

You are talking about the mechical cause and he is talking about the human effect. So he could not be total nonsense unless...

 

um comparing 2 differeent types for gearbox for FC then taking human effect into play is like comparing 2 different audio system then juding the better 1 by which user turns up the volume higher..

[Lammy84]

==========

 

Thats why I say autos have almost as good FC as a manual. It still loses abit of economy until it locks-up.

 

But for those drivers who over-rev their manuals, then their FC wil b worse.

 

take the same driver who likes to over-rev and have him drive both the auto and manual, the auto will still come out worst off.

[Krado]

Watcha think?

 

I take public transport to work everyday for the best FC, since the car doesn't even have to start the engine.

[The_Bear]

I take public transport to work everyday for the best FC, since the car doesn't even have to start the engine.

you neh neh pok FC.

[Nullifi3d]

I would say an auto toyota wish will have better FC compared to a manual lotus elise; same engine no?

[Krado]

you neh neh pok FC.

 

Learn-ed from you.