4AT vs. 5AT fuel efficient

Is a 5AT more fuel efficient than a 4AT, if we consider the same car?
If yes, in which road condition?
The number of RPM on a 5AT is different (lower) than a 4AT for the same
speed?

Thanks,
Chris

 

What year and model are you talking about?

It really depends on other features of the engine and tranny
and driving needs.

www.fueleconomy.gov is a great resource for comparing fuel
efficiency of different years and models, especially since
individuals may now report their personal experiences with
fuel efficiency.

 

In general, maybe. Look at the final drive ratio for the two cars.
The four speed may actually have a more fuel efficient top gear. The
problem is that you'll give up performance for this.

 

Element 2004 - 4AT vs. Element 2005 - 5AT

 

depends how well the ratios are matched to the power/torque curves of the
engine. small differences in rpm's don't mean too much when it comes to
cruising economy - you can have lower rpm's but higher gas consumption if
the curves aren't a good match.

 

| >Is a 5AT more fuel efficient than a 4AT
mysterios deserve no info

| In general, maybe.
Often 5th / 6th gear is usable only on Germany's autobahn, &
unusable in most countries unless user can ignore speed limits.

 

Incorrect. In my Fit, 5th lets me loaf along at around 3000 RPM and
65 mph. When I need to get around someone, it's usually because
they've dropped my speed below 60. So I drop to 4th whle signalling
and pulling out.

 

| 5th lets me loaf along at around 3000 RPM and 65 mph.
65 mph = 104.6 kph, @ this speed my SM4 ( final & 4th
gear combined ratio = 3.132335, axle height 30 cm via 205/
65R15 tyres, zero toe-in ) needs just 104.6 x 8750 ÷ 33 x
3.132335 ÷ 30 = 2895.8 rpm.
Either your 5th gear's ratio is too high, or axle ( tyre ) height
is low.

| I drop to 4th whle signalling and pulling out.
Sounds like a manual gearbox. Your gearbox is automatic ?

 

Manumatic. But my Civic was a manual and the same general effect
applied. It's just that I can now stand on while shifting and
signalling.