MPG's --- A/T vs. MT

[pbm]

I have noticed that many models are claiming that their A/T version gets better
MPG's than their M/T version. The 2013 Ford Focus and the Mazda3 both claim to get 2 MPG's better with their A/T. Is this what you've experienced or is this difference "on paper only"? One of the many advantages of a stick shift was better MPG's..is this no longer true? Thanks

PS: I understand the new A/T's (with their 6 speeds or dual clutches etc..)..are much more efficient than older designs. I'm just asking what 'real world' experiences have been?

 

[rjundi]

A well driven manual with an aware smart human can achieve higher MPG than an automatic. How? A human can see far ahead and anticipate the proper shift well ahead and proactively. An automatic is reactive to conditions occurring at he moment.

 

[Shannow]

I agree, but an auto can be trained (programmed) to beat any govt test cycle...and be absolutely woeful to drive out in the real world.

When they recall them and reprogramme them, do they have to resubmit them ?

 

[kam327]

Originally Posted By: rjundi
A well driven manual with an aware smart human can achieve higher MPG than an automatic. How? A human can see far ahead and anticipate the proper shift well ahead and proactively. An automatic is reactive to conditions occurring at he moment.


I disagree. Today's modern automatic will upshift as much as possible to keep RPM's as low as possible in all conditions which is how they achieve the better fuel economy. When I shift my Focus manually I find I'm letting the RPM's get higher on average just because the car operates more smoothly that way. And I doubt that the everyday driver is manually shifting as efficiently as the testers were that determined the EPA ratings.

 

[Smoky14]

Well I have a 2012 Fusion 2.5L with a manual 6speed. Worst mileage so far has been 30.8 the best was 37.9. This is measured not the readout. Normally gets about 33MPG in everyday use.

Anyone have a 2.5 with auto to compare?

Smoky

 

[nitehawk55]

Some auto's now have a higher OD gear now then the manual so mileage on the hwy will be better under the right conditions .

 

[skyactiv]

Auto makers know anyone buying a stick vehicle in the U.S. is an enthusiastic driver. Many stick vehicles have gear ratios and a final drive ratio for better performance rather than all out fuel economy. The Chevy Cruze ECO manual is a welcomed exception.

The 2013 VW Jetta with the bottom feeder 2.0 gas engine is rated 34 highway with a stick and nose dives to an embarrassing 29 highway with the 6 speed automatic. The automatic saps power from the lousy 115 horsepower engine.

 

[LotI]

Originally Posted By: rjundi
A well driven manual with an aware smart human can achieve higher MPG than an automatic. How? A human can see far ahead and anticipate the proper shift well ahead and proactively. An automatic is reactive to conditions occurring at he moment.

...and, you can't coast in an automatic. My average mileage with my ZX-2 was 42 by coasting...approaching lights, down long hills, reducing speed limits. The car is rated at 30 hwy the new way, 33 old. An idling engine going 55 mph gets 250+ mpg according to my Scanguage II.

 

[ksp7498]

Realistically, a MT will always get better mileage than a traditional torque converter automatic because the torque converter is not 100% efficient but a mechanical clutch is. Once you throw CVTs and DSGs into the mix I expect they would all perform very closely.

Something is definitely weird about the EPA test cycle, though. My MT Fit is rated 27/33 but I get 34-38 combined depending on how much highway cruising. Even with tons of city driving the lowest I have ever seen is 33, and I don't baby it either. I routinely run it up in the 5-6k rpm range.. I can't imagine how I could get it down to 27.

 

[sparky123]

On my 12' Golf, the auto transmission, when in 6th gear, will coast (idle rpm) at speeds below 40mph. With buttery smooth transmission shifts, light clutch action, etc...nothing as good as a manual. Honestly, I wish I could reprogram my auto transmission as I dislike the transmission going into higher gear at the lowest speed. 1-5 aren't bad, but 6th gear at 32mph lugs the engine a bit. (Thank goodness the engine 2.5L has lots of torque and quickly downshifts if gas is applied.)

 

[DuckRyder]

Just remember that the Dual Clutch "Automatics" are not really automatics but automated manuals they do not have the loss through the torque converter that a real "automatic" has. Mechanically most Dual Clutches are closer to a manual than an automatic.

Our TDI regularly best the EPA numbers with DSG.

 

[dparm]

Originally Posted By: rjundi
A well driven manual with an aware smart human can achieve higher MPG than an automatic. How? A human can see far ahead and anticipate the proper shift well ahead and proactively. An automatic is reactive to conditions occurring at he moment.



Lately I've discovered that my brain is not good at deciding which gear to be in on the M3. In manual mode, I am doing about 10-15% worse. When I leave it in full-auto, the car is shifting into the higher gears much earlier than I would've expected, and seems to be quite happy loafing along in 7th gear at 1500rpm, even in the more aggressive Drivelogic selections.

 

[KrisZ]

From the EPA test it's a simple matter of ATs being programmed to take full advantage of the test.
Someone mentioned that the EPA tester is being more efficient at shifting manual transmission than average person, well it's not the case. The EPA protocol has certain RPM shift points that the test driver must adhere to, he/she definiteley does not drive to maximize fuel economy in the test, they simply follow the protocol, where the AT transmission shifts however it likes. And like mentioned already, gearing is usually different in MT as well, so it's hard to do a true apples to apples comparison.

 

[Danh]

Originally Posted By: LotI
Originally Posted By: rjundi
A well driven manual with an aware smart human can achieve higher MPG than an automatic. How? A human can see far ahead and anticipate the proper shift well ahead and proactively. An automatic is reactive to conditions occurring at he moment.

...and, you can't coast in an automatic. My average mileage with my ZX-2 was 42 by coasting...approaching lights, down long hills, reducing speed limits. The car is rated at 30 hwy the new way, 33 old. An idling engine going 55 mph gets 250+ mpg according to my Scanguage II.


For many cars, coasting in gear results in fuel shutoff, so by putting the car in neutral and "coasting", you may actually be hurting your mileage as fuel is required to keep the engine running rather than the inertia of the car itself.

 

[dparm]

Something we aren't bringing up here is that sometimes the AT models have a better top gear and/or lower FD.


M3 6MT
6th gear = 0.872
FD = 3.678

M3 M-DCT
7th gear = 1.000
FD = 3.154


Curiously both are rated 14/20mpg, 16 combined.

 

[HerrStig]

Originally Posted By: nitehawk55
Some auto's now have a higher OD gear now then the manual so mileage on the hwy will be better under the right conditions .
One of the problems with agressive OD ratios in manual applications is "lugging" especially in small 4 cyl engines, a torque converter can reduce that problem by smoothing the power flow. It seems the newbie manual driver, in particular, doesn't understand when to downshift.

 

[Smokescreen]

On the highway it is entirely possible to do better in an auto. The better final drive ratios plus locked up torque converter and no slippage so it often yields lower rpms sometimes by a couple of hundred or more. My lifetime average of over 190,000km is above 38mpg.

In the city you can do close if you drive slowly, but you just don't have as much up-shift ability if revs are below 2000 sometimes. Deceleration fuel cutoff really has allowed autos to make great strides in the city.

 

[coolbird101]

Originally Posted By: Smoky14
Well I have a 2012 Fusion 2.5L with a manual 6speed. Worst mileage so far has been 30.8 the best was 37.9. This is measured not the readout. Normally gets about 33MPG in everyday use.

Anyone have a 2.5 with auto to compare?

Smoky

We have the same 2.5 in our Mazda with auto., our worst mileage has been 25 with the best being 30, typical everyday driving brings about 27.5. We have taken one long hwy trip with it, driving 80 - 85 mph delivers about 28 mpg.
Is your car a hybrid? I have no idea how your getting those mpg's, way out of line from what we are seeing.

 

[Kuato]

I wonder how all this lugging in higher gears affects the longevity of the head gasket.

 

[dparm]

Originally Posted By: Kuato
I wonder how all this lugging in higher gears affects the longevity of the head gasket.




Not sure. My father always told me not to lug an engine as it stresses just about everything: pistons, con rods, oil, output shaft, clutch/torque converter/flywheel, motor mounts, etc.