Automatics getting better MPG than manuals?

[daemonite]

On a stick shift, leaving it in gear while slowing down to a stop can save you a tiny bit of gas.

Also just shifting at a lower rpm works well also...the only downfall of my manual vs the automatic is the manual has a very long 5th gear.

I drive 65mph at 3000rpm + where as the automatic is about 500rpm less

 

[greenjp]

I'm very curious to see how the numbers change when they start using the revised rules in the next year or two.

Remember folks, the "highway" rating is derived from a test that averages something like 45 or 50 mph. In many cars, this isn't even in top gear! I don't hit 5th in my 9-5 Aero until I'm closer to 60 mph.

jeff

 

[daemonite]

My car actually gets quite close to EPA...

I linger around 26 to 28...EPA rates it at 29

 

[1sttruck]

A couple of friends with similar make diesel pickups but with autos get as good of mileage as I do with a stick, but they're geared a bit taller.

Trying to keep an older running I despise autos. Although I can check engine codes with a jumper wire and the check engine light you need a separate tester for the auto. It seems to have fewer sensors than the engine but more solenoids, and is as complicated mechanically.

 

[Gary Allan]

quote:

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quote:You can use less accelerator pedal and keep it at say 10-15% Throttle Position through the gears.

Gasoline engines are more efficient at higher throttle openings (and, therefore, higher load) so this is not the most efficient way to accelerate.

In a manual you can accelerate at 80% throttle and shift at 2000RPM AND skip gears. Try that with any automatic.

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Sure, brian ..you reduce the throttling losses by opening up the throttle under low rpms.

Try that with an automatic. You just stay in gear longer. Unless you've got "lugging" programing as standard equipment ..or can alter your shift points at will ..you're SOL

So, what's a sensible auto owner to do (common automatic ..not some bang whizzo manual in automatic clothing)

I would think, and empirical data of a lifetime strongly suggests, applying as little throttle as possible to achieve the earliest possible shifting point where your target cruising speed is attainable.

Or is a WOT start from a standstill to cruising speed a neo-economy move?? It never worked for any car I ever owned in my lifetime. However driving with an egg between my foot and the pedal yielded MPG improvements in spades.

 

[brianl703]

No, because at WOT the mixture is richened.

I don't see any reason that the programming for the automatic couldn't work so that you can lift off the gas pedal a bit when you want it to shift up to the next gear..and when you put your foot back in it, it won't downshift unless you really put your foot into it. I think some of them do do this.

As far as not downshifting until you put your foot into it, according to the Scangauge, I was able to get my mom's 2.2L Ecotec Malibu Classic with the 4T40E automatic all the way to 90% engine load (WOT is 100%) in 4th gear without it downshifting into 3rd. I thought for sure it would have shifted into 3rd long before the engine load got that high, but perhaps I underestimated the power of good programming.

 

[radiometer]

brianl703,

I've used a modified version of your above suggestion. It has been with a cool engine and I needed to get going well along without racing said cool engine. I rarely go WOT. I can still move out at good acceleration and ease up on the throttle when I want it to change and it will do so. I can then add some throttle to continue my acceleration in the higher gear.

Works well for me.

 

[sprintman]

Latest Ford Falcon and Territory have ZF 6-speed adaptive learning auto. What a car and what a transmission. XR6 Turbo with that trans is a marriage made in heaven IMO. If only Ford U.S didn't have the NIH problem Americans and Canadians could sample this beast. At least GM arn't reticent about importing Aussie made product, eg Pontiac GTO.