Speed For Optimum Gas Mileage

[dinahmare]

I have a 45 minute commute to work which is a nice easy drive on secondary roads. I pretty much have the option to go anywhere between 40 and 60 mph. I expect the best gas mileage occurs just over the point at which the engine goes into overdrive. Is there a general speed at which this happens? Usually I am happy to do do a lower speed but it occurs to me I should push it a bit when possible to optomize the gas use.

Does anyone have some insight on this topic?

[Hoovie]

There is some info and advice in the Blob Watch topic on the forum.

in essence, the best economy will be gained at the lowest engine speeds, plus the faster you go, the greater the power needed due to wind resistance, so the more gas is used.

If you want to drive at the most economical speed between 40 and 60, check what the Rev Counter is saying once the car is in the highest gear and keep to the lowest speed above 40MPH that doesn't make the car drop down a gear or 'hunt' between gears (I am assuming you have an auto car)

Also when getting up to speed, take it easy and don't accelerate hard and that will make a big difference compared to those drivers that use the Auto kickdown a lot.

[Fujisan]

Agree pretty much with all Hoovie had to say

Basic rule: More speed, more fuel used!

But I think you have to factor in traffic conditions, nobody is saying drive at 40mph in heavy traffic when everybody else is doing 70mph. You have to use your own good judgement as to the balance between fuel economy and a speed you feel safe and comfortable at, for the road and traffic conditions. ;)

Anticipation and road observation are key elements. Avoid heavy acceleration and heavy braking (your just wasting energy spent getting up to that speed)

Keeping the engine at a low constant revs in its highest gear will pay you dividends

And the bonus ball, not only will you be saving fuel and money, you will finish your journey generally more relaxed

Good luck

[john1944]

Agree pretty much with all Hoovie had to say

Basic rule: More speed, more fuel used!

But I think you have to factor in traffic conditions, nobody is saying drive at 40mph in heavy traffic when everybody else is doing 70mph. You have to use your own good judgement as to the balance between fuel economy and a speed you feel safe and comfortable at, for the road and traffic conditions. ;)

Anticipation and road observation are key elements. Avoid heavy acceleration and heavy braking (your just wasting energy spent getting up to that speed)

Keeping the engine at a low constant revs in its highest gear will pay you dividends

And the bonus ball, not only will you be saving fuel and money, you will finish your journey generally more relaxed

Good luck

Does it pay to turn your engine off at traffic lights, and road works, or is there a surge in fuel consumption when restarting.

[chatman]

Does it pay to turn your engine off at traffic lights, and road works, or is there a surge in fuel consumption when restarting.

Re-starting does not use more fuel as opposed to sitting in traffic with engine running. If you know your gonna be sat there for more than 5 minutes turn the engine off. Modern vehicles can handle the stop starts easily. I would not turn the engine off at traffic lights as these commonly don't have long waiting times... rail road crossings and heavy traffic jams do....

[Hoovie]

is the keep running v. turn off window only about 1 minute if you have a car that is warmed up and starts immediately on a key turn?

I tend to turn off my engine when I know there will be a wait due to jams, SALT roadworks, etc. plus at red traffic lights with which I am familiar with the sequences andknow I will be hanging around.

[chatman]

SALT roadworks,

What's this....do they SALT the roads a lot down south then Hoovie ??? ;) ;)

[Hoovie]

SALT = Smelly Arthritic Lethargic Tractors

stuck behind one of them, I turn off the engine and PUSH the car instead to keep up :)

[anchorman]

I have a 45 minute commute to work which is a nice easy drive on secondary roads. I pretty much have the option to go anywhere between 40 and 60 mph. I expect the best gas mileage occurs just over the point at which the engine goes into overdrive. Is there a general speed at which this happens? Usually I am happy to do do a lower speed but it occurs to me I should push it a bit when possible to optomize the gas use.

Does anyone have some insight on this topic?

On your auto transmission the gearbox goes into overdrive at 45mph. So the optimum will be somewhere just above 45mph and under light throttle loads to resist the transmission from shifting down.

Take no notice of my UK colleagues. Everybody here knows that you are never held for more than a few seconds at our ultra efficient railway level crossings! However tractors are a problem and so are Land Rovers and crashed Subaru's.

[bitman]

i don't use the speedo as a reverence but the RPM's. when i accelerate i keep it on 2000 rpm all the way this will give me enough speed to drive on those secondary roads. on dual carry roads i drive about 2200 / 2500 RPM

look at my real time MPG to get an idea.

[anchorman]

Quite right Bitman, its just that the US spec vehicle with auto transmission needs to exceed 45mph to get into overdrive.

[local hero]

SALT = Smelly Arthritic Lethargic Tractors

stuck behind one of them, I turn off the engine and PUSH the car instead to keep up :)

wasn't there a huge SALT 2 conference, i didn't know it was about tractors Oh incidently, what do you call someone who used to like tractors

but doesn't any more,,AN EXTRACTOR FAN, sorry know its an old one. but at least its clean