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

[kam327]

Originally Posted By: LotI
...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.


You're just plain wrong on two counts dude.

 

[dparm]

Originally Posted By: kam327
Originally Posted By: LotI
...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.


You're just plain wrong on two counts dude.


Agree. As soon as you take your foot off the gas, the engine cuts the fuel. It's why your instant MPG will show a null value or something like 99.9mpg.

 

[NateDN10]

Originally Posted By: dparm
Originally Posted By: kam327
Originally Posted By: LotI
...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.


You're just plain wrong on two counts dude.


Agree. As soon as you take your foot off the gas, the engine cuts the fuel. It's why your instant MPG will show a null value or something like 99.9mpg.

There was a thread about this a few weeks ago. Some posters were saying that in 5th gear (5MT), the engine would rarely go into DFCO, but it was more common in 4th and 3rd gears.

For me, it depends on how long I'll be coasting. If there's a long, slight downhill I can shift into neutral and not have to touch the gas the whole time. Whereas if I'm in 5th gear, the engine braking slows down the car and I have to accelerate to stay at the speed limit.

 

[KrisZ]

Originally Posted By: dparm
Originally Posted By: kam327
Originally Posted By: LotI
...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.


You're just plain wrong on two counts dude.


Agree. As soon as you take your foot off the gas, the engine cuts the fuel. It's why your instant MPG will show a null value or something like 99.9mpg.


Actually LotI is not wrong. Many older Fords don't cut the fuel completely off and coasting saves more fuel that leaving it in gear.
That's the case with my zetec ZX5.

And plenty of traditional automatic didn't take advantage of fuel cut off, even if equipped with such a feature, simply because the TQ was only locked in the highest gear, in every other gear the engine would simply go to high idle speed whenever gas pedal was lifted.
It is only fairly recent new ATs that can take full advantage of fuel cut off by locking the TQ past the first gear.

 

[Cujet]

Certainly, the difference in MPG is not much of a factor with very modern-design transmissions.

The Prius, for example is an automatic.

However:

The VW TDI (DSG dual clutch automatic) diesel rating is very close for auto vs. manual. But real world MPG of the manual is significantly better.

And from what I hear, the Cruse ECO manual is significantly better than it's auto counterpart.

 

[badtlc]

Mazda only claims a 1MPG improvement with their ATX vs MTX. I drive the 6spd MTX and I don't see anyone with an ATX on the mazda3 forums claiming anywhere near the MPGs I get in mine. My sticker says 39 MPGs HWY, but I get 43-44 MPGs on my work commute which is about 28 miles round trip and around 50/50 cty/hwy driving. My previous cars with ATX, I could not touch the HWY rating on my work commute, only on longer trips.

EDIT: I also think manufacturers intentionally sabotage their MTX MPG ratings a bit (only small amounts) to help push the ATX since they make more on those.

I also have one variable in my situation some others don't with regards to my MPGs. I also run premium gasoline, only. Not sure how much difference it makes, but I do know it gets better MPGs with premium.

 

[surfstar]

Mazda CX5 2.0L MTX 26/35 ATX 26/32

10% difference for hwy - that's significant.

 

[badtlc]

Originally Posted By: surfstar
Mazda CX5 2.0L MTX 26/35 ATX 26/32

10% difference for hwy - that's significant.


Yup. This is why I question it in general. I know why Mazda is willing to advertise the MTX as better MPGs for this case. These values put them 1st place in the CUV market for MPGs. It is great marketing.

The difference is so drastic though, you gotta wonder why it doesn't appear on all models.

 

[surfstar]

Originally Posted By: badtlc
Originally Posted By: surfstar
Mazda CX5 2.0L MTX 26/35 ATX 26/32

10% difference for hwy - that's significant.


Yup. This is why I question it in general. I know why Mazda is willing to advertise the MTX as better MPGs for this case. These values put them 1st place in the CUV market for MPGs. It is great marketing.

The difference is so drastic though, you gotta wonder why it doesn't appear on all models.


Yeah, it'll be interesting to see if they offer the 6MT with the 2.5L CX5 and what the mpgs would be. Or heaven-forbid a 6MT 2.2 diesel! (fingers crossed)

 

[kam327]

Originally Posted By: KrisZ
Actually LotI is not wrong. Many older Fords don't cut the fuel completely off and coasting saves more fuel that leaving it in gear.
That's the case with my zetec ZX5.


Agree, but I thought we were talking about today's modern transmissions, not yesteryear's.

 

[MetalSlug]

I don't note any different on miles on auto or manual . BUT if you watch some car commercial about fuel miles . Listens closer at the end when they talk really fast . You note they say " mpg on this car is equip with manual transmission "

 

[dparm]

I would rather not put the wear-and-tear on the trans to keep shifting in and out of neutral just to gain a tenth of an MPG while coasting. A bit of engine braking is healthy anyways, and saves some wear-and-tear on the brakes.

 

[sciphi]

Depends on the car. A Cruze Eco MT will slaughter other gas Cruzes for MPGs, but it has many changes other than the manual transmission to help it do so. And, the AT (traditional torque-converter Aisin 6-speed) Cruze Diesel will slaughter a Eco MT for highway fuel economy.

 

[KrisZ]

Originally Posted By: kam327
Originally Posted By: KrisZ
Actually LotI is not wrong. Many older Fords don't cut the fuel completely off and coasting saves more fuel that leaving it in gear.
That's the case with my zetec ZX5.


Agree, but I thought we were talking about today's modern transmissions, not yesteryear's.


Here is thing though, not all today's transmissions lock the TQ in all gears, some still only lock in final gear, some only in the top two gears and some in all gears. It's not as clear cut as today's transmissions vs yesterday's.

 

[hattaresguy]

Modern transmissions and computers can shift better and faster than any human can.

Its not the 1980's or 90's anymore for that matter.

The difference aside from speed is that people get tired, computers don't.

Its like passage making on a sailboat. Sure you can helm it manually, but you won't cover distance as efficiently if you let the chart plotter and autopilot do it. I can beat them while I'm at 100%, but after 1, 2, or 8 hours I'm way off that. But the computer is always working at 100%.

 

[Smoky14]

Originally Posted By: 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.

It's NOT a hybrid, just a cheap S model. Normally shifted at about 3K and not babied at all. The DBW in this thing really drives me nuts as it won't let me work the throttle, I guess I'm too stupid. My 99 Acura coupe gets 35-39MPG with a 5 speed manual but is much more fun to drive because the driver determines the throttle position.
Hope that helps.
Smoky

 

[pbm]

I'm happy to have gotten so many good responses to this thread.
What I'm getting is that an M/T is capable of getting the same, if not better, mpg's than an A/T (depending on the vehicle).
I'm getting the urge to pick up a Focus or Mazda 3 M/T as a commuter car. The only problem is the rest of the family doesn't drive stick...we'll see how it goes.
Thanks for the reply's.

 

[badtlc]

Originally Posted By: pbm
I'm happy to have gotten so many good responses to this thread.
What I'm getting is that an M/T is capable of getting the same, if not better, mpg's than an A/T (depending on the vehicle).
I'm getting the urge to pick up a Focus or Mazda 3 M/T as a commuter car. The only problem is the rest of the family doesn't drive stick...we'll see how it goes.
Thanks for the reply's.


I faced a similar issue. My wife didn't know how to drive a stick and swore she couldn't be taught. She finally realized how bad I wanted a stick and agreed to try. She was "good enough" after 2 driving lessons. She only needs to work on partial throttle, slow driving type scenarios (parking lots and traffic jams). She isn't even very coordinated. Anyone can learn if they want to and someone takes the time to teach them properly.

 

[ledslinger]

My wife's 2001 4 cyl MT Accord commonly gets 32 MPG highway. Sometimes more. I drove my brother's wife's 2000 Accord V6 AT on a 400 mile trip and got 31 MPG.

 

[surfstar]

Originally Posted By: pbm
I'm happy to have gotten so many good responses to this thread.
What I'm getting is that an M/T is capable of getting the same, if not better, mpg's than an A/T (depending on the vehicle).
I'm getting the urge to pick up a Focus or Mazda 3 M/T as a commuter car. The only problem is the rest of the family doesn't drive stick...we'll see how it goes.
Thanks for the reply's.


The 2013 Mazda3s have $1500 offers right now. Once the 2014s hit the dealership, I think you could really score a deal on one. Another thread mentioned a dealership in FL that was down to ~$15.5 for a 2013 MTX sedan already...