mind boggeling presumption? (manual more efficient than automatic?)

[dmafanp]

The Argument between getting a manual or a an automatic is trivial. A modern automatic tranny will shift at peak torque, perfectly everytime. With a manual there is human error. Some of the new vehicles have automatic trannys that surpass manual in the epa. would you save more suel over time haveing consistant shift points or variable shift points assuming one wants to save the most amount of fuel possible and is not the only driver of the car (wife).

[P-hack]

Lol, the manufacturers use "sportier" gearing in a lot of manuals. Look at auto vs/manual in cars designed for efficiency and it becomes much clearer that manual has the lead. And it enables lots of other techniques, where the automatic designers "automated away" your options for more efficiency. You say human error, I see humans doing a much better job at saving fuel when they learn what is going on. Human error exists on many levels, I could say that being "lazy" about shifting and rationalizing automation even though it is demonstrably less efficient than a skilled driver (what a concept!) with a stick is a huge human error, since we are discussing efficiency.

Automatics are getting better, but more pricy too, and they are heavier, and sloppier, harder to repair, and the shift points are built for your average mash and go driver. Heck most of the time you can't even safely EOC in them, they lose big time right there, no contest once you relearn how to drive.

[dmafanp]

This is great I would love to take a smash and go driver using both manual an auto and compare te differences in real world scenarios clearly the manual would win but I want numbers thanks

[P-hack]

Well there is this: EcoModder Fleet list - EcoModder.com

You have to go scroll down pretty far before you get into serious numbers of automatic cars. There are a couple fairly high mpg priuses, but I can tell you from first hand experience it is much harder to drive them uber-efficiently than a stick. You have to outsmart a layer of automation to get there.

Or look at something like a 2014 yaris, users are reporting ~30% better efficiency with the stick:
Fuel Economy of 2014 Toyota Yaris

[Mista Bone]

Automatics are heavier and you have to use energy to pump fluid around.

Now once everything is locked up the only real difference is all the extra spinning weight. Think how some here worry just about wheel weights.

The perfect tranny for MPG would be a CVT. With proper programming the engine would stay at its peak economy based on load and throttle inputs.

But they still have reliability issues.

The one thing missing, the transmission nor ECM can look ahead and judge terrain or traffic conditions...YET!

[cbaber]

Automatics have improved drastically over the years, but mainly in adding gears. Some of them are up to 8, 9 speeds?! Automatics usually have higher highway speed RPM which really hurts fuel economy.

I will always prefer a manual. An automatic won't ever let me "chug" around at 900 RPM in 5th gear in town. The most fuel efficient gear at any given speed is the one with the lowest RPM, regardless of engine load (unless you go into open-loop rich mixtures). Automatics can't control the engine/transmission as completely as the driver can.

What has changed in manual transmissions over the last few decades? Almost nothing. They are bulletproof if you drive them correctly. Automatics are more expensive to repair/replace/maintain. CVT's are even worse in that area, but have become much better.

Also, there is just something fun about slapping the gears around. It feels sportier. You are more connected to the car.

[MetroMPG]

Learning about how manuals are operated during the EPA test -- with prescribed (non-eco) shift points and prohibited coasting -- makes it clear why it's far easier to beat the EPA (by a bigger margin) with a stick than a slushbox or CVT:

http://ecomodder.com/forum/showthrea...ing-27416.html

Originally Posted by dmafanp

This is great I would love to take a smash and go driver using both manual an auto and compare te differences in real world scenarios clearly the manual would win but I want numbers thanks

It's going to depend on the individual car, but here are numbers for a couple:

2014 Mitsubishi Mirage 1.2L:

Automatic CVT
40 mpg (US) -- combined EPA rating
39.2 mpg (US) -- average of 17 actual owners

Manual 5-speed
37 mpg (US) -- combined EPA rating
42.7 mpg (US) -- average of 11 actual owners

source: Mirage fuel economy log - MirageForum.com

2012-2014 Nissan Versa 1.6L sedan

Automatic CVT & 4-speed
32.5 mpg (US) -- combined EPA rating (average of CVT & 4SP)
32.7 mpg (US) -- average of 14 actual owners

Manual 5-speed
30 mpg (US) -- combined EPA rating
35.6 mpg (US) -- average of 6 actual owners

source: Micra 1.6 real world fuel economy / mileage reports from owners - Micra-Forum.com

Fuelly - analyze

Fuelly sucks because it doesn't break out transmission type or engine size in its data, but if you comb through details/results for a specific vehicle, you can sometimes put together a comparison based on drivetrain.

assuming one wants to save the most amount of fuel possible and is not the only driver of the car (wife)

This is a HUGE wildcard. I regularly hear manual drivers (I'm talking non-performance car types) driving down the road near the speed limit (50 km/h / 30 mph) in 2nd gear in my neighbourhood. If you don't have the knowledge/skill/motivation, you're better off in an automatic for several reasons, not just MPG.

[hamsterpower]

Originally Posted by cbaber

Automatics have improved drastically over the years, ... An automatic won't ever let me "chug" around at 900 RPM in 5th gear in town.

Actually... I bought my wife a 2012 VW Golf 6 speed auto last year. It really does an amazing job. I cruze around town (35-40ish) in 6th at 1000RPMs in auto mode. I can easily beat the EPA with 37MPG average without using manual shift mode. In fact it is so quiet it is hard to beat the auto around town in manual shift mode. I do wish I could neutal coast from manual shift mode, but I can from auto mode. Not that I really need to as it coasts well most of the time already.
The manual mode is better on the highway as I can leave it in 6th and stay easy on the accellerator. In auto mode every rise causes a down-shift.

The cruse control could be better though. I rented a Mazda 3 with "Sky active". (whatever that is?) Also an auto, that cruse control was great. I'm pretty sure it was engine off coasting on cruse control at times.

[user removed]

Almost 10 years ago the consortium of the EPA, University of Michigan, Ford, Parker Hannefin and some others predicted some amazing numbers for fuel economy in vehicles. I have posted that document here before.

Their precitions included an 80% increase in economy through powertrain improvements, with all other improvements combined for a total 120% improvement.

They also predicted that a class 2 truck with a GVW of close to 10,000 pounds would achieve 58 MPG. I have the chart that breaks down the stages of improvement.

The date those predictions were supposed to be in place is NOW.

I have my own favorite powertrain configuration, where the transmission replaces friction brakes completely, the exception of the emergency brake, but it will be a while before a functional example is built.

The original post title is provocative. Extreme techniques, combined with very low average speeds, about half of my own, will always produce exceptionally high MPG averages. Where you live can make a huge difference. That's great for those who are in that situation, which is not and never will be my own. Mag Pearl is number 36 close to the top 10%. Only 9 of the 35 higher vehicles are less than 14 years old, and some of them are models never sold in the US.

The gap is closing. My Fiesta's automated manual transmission is one pathway to the future of shiftless driving, My dream is another. Only time will tell which one prevails, but when all the factors are combined with the capability of the vehicle to anticipate where it is going and when it must stop the automated choice will prevail.

regards
Mech

[P-hack]

Originally Posted by Old Mechanic

...Only time will tell which one prevails, but when all the factors are combined with the capability of the vehicle to anticipate where it is going and when it must stop the automated choice will prevail.

If you have a coordinated system of transport (kinda like public transport) then there are efficiency gains to be had eliminating the reactive component of driving, i.e. the central controller will space everything out just right and stoplights won't be necessary, the cross traffic will weave, usually without incident. But we are not talking about driving anymore...