Why Manual cars are more fuel efficient than automatic?

[The_lasting_impression]

AoA! I've read and heard here and from the people concerned with automobiles that the manual gear cars are more fuel efficient than automatic ones. The common man logic says that in automatic gear cars, gear shifting is more systematic so it should be more fuel efficient while manual gear shifting may be different for different drivers so it might be more hard on fuel but we are told the otherwise. Will the experts please elaborate?? Thanks in advance

[faiz.aslam.121]

Manual- You can change gears at 2500 rpm and even at 1500 rpm. The latter will drive with WOT and use more fuel. So low (est) rpm's isn't everything.
Automatic- 10% less fuel efficient due to the Torque converter. Drive with a soft paddle and it will up shift quicker.

[kskhan86]

IMO auto tranny cars if driven with light foot tend to shift gears at lowest possible rpms. And eventually always remain at the lower rpm band. E.g. in khi city, u r cruising on 60km/h on a 05 civic pros, its rpm remains on 1.5k more or less. But similarly manual tranny civic 05 rpm remains at 2k rpm in 4th gear & in 5th gear a bit lower than that bt engine stalls a bit. Secondly, in auto tranny cars one lifts his foot from gas pedal, rpm sets itself to lowest mark for that engine speed which is nt the case in manual. One lifts the foot from pedal, rpm remains at that mark until cars motion itself is slowed

[argtr65]

Idle rpm of automatic car is higher side as compare to manual,because of this fuel consumption of automatic car is higher side than that of manual one.

[kskhan86]

No bro. Its nt on the higher side.

[kskhan86]

I dnt want to quote fuel consumption figures of both manual & auto tranny cars. But rpm of auto cars remain.on lower band.

[aliusman420]

Prius is an automatic and one of the most fuel-efficient vehicles

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[bhasnain]

Automatic transmissions were said to be more heavy on fuel due to energy wasted by transmission fluid while turning impeller - Stator - Turbine - Rotor shaft. But these days new generation automatic transmission are very fuel economic and almost equal to manual transmission. Just Google and read.

Manual transmission is only fuel efficient if handled by a sensible driver.

[imrananr]

Prius is an automatic and one of the most fuel-efficient vehicles

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Hybrids are not considered here.....

[sgg1983]

Its sooooo simple... You have RPM in your hands in the manual transmission and shift gears as u desire... put a car into 5th at 60km and RPM will be much lower than in the 4th gear at the same speed.. and also lots of cars are 4gear auto while manuals 5gear.

[aliusman420]

Hybrids are not considered here.....

CRZ manual is very less fuel efficient than automatic Prius.

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[Umairlal]

and what about the consequences of early shifting?

[ZainMahdi]

Manual- You can change gears at 2500 rpm and even at 1500 rpm. The latter will drive with WOT and use more fuel. So low (est) rpm's isn't everything.
Automatic- 10% less fuel efficient due to the Torque converter. Drive with a soft paddle and it will up shift quicker.

Or you can cruise at 1500 with a light throttle. Unless its an under powered 660 cc, it will still maintain its speed . The manual would blow the auto away in this situation.

[ZainMahdi]

and what about the consequences of early shifting?

Define early shifting? I shift gears at 2000 rpm in my Cultus VXR with no problem. It can cruise at as low as 1300 rpm without lugging or knocking. As for engine damage, it can still go above 130 kph at 310000 km.

[imrananr]

CRZ manual is very less fuel efficient than automatic Prius.

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That's what I am trying to tell you here, PRIUS is a HYBRID vehicle, hence it's it is more fuel efficient than conventional vehicles....

[ZainMahdi]

That's what I am trying to tell you here, PRIUS is a HYBRID vehicle, hence it's it is more fuel efficient than conventional vehicles....

CRZ is a hybrid. A hybrid designed for performance rather than fuel economy though.

[aliusman420]

CRZ is a hybrid. A hybrid designed for performance rather than fuel economy though.

a small 1.5L engine and performance-oriented?

[ZainMahdi]

a small 1.5L engine and performance-oriented?

Its 0-100 time is faster than Civic hybrid and Prius. The suspension is also set up for hard cornering rather than comfort. It has a manual transmission which is much more fun than a CVT. Performance isn't all about absolute top speed .

[Xulfiqar]

you guys are trying to compensate for fuel by driving like a "dadi amma" - every engine has a specific usable powerband. Some engines dont even have the torque of a 2 yr olds arm muscle at low rpm.

...

back to the question, the reason manuals get more economy is mostly due to the reason of lack of losses in the torque converter and also due to more gearing control with manual - the automatic transmission cannot "see" what the human can.

[muradi]

Don't know the Reason but manual is more fuel efficient than Auto, Personal experience