I used to drive most of my way to work in 6th gear with just a tiny bit of throttle and the fuel computer reading anything above a couple of hundred MPG. I lived at about 1000 feet and worked 15 miles of straight motorway away at about 300 ft. Thing is I couldn't get more than 35 or 40mpg on the way home when I had to climb the same hill, so overall 50-60mpg was my best average. I could get just the same with the cruise control set to 75mph on a 350 mile journey from Scotland to Birmingham, which is up and down over Dumfries and Galloway and the Lake District, with every motorway gradient in between, so I don't think it really makes much difference. It all averages out.
Wouldn't you coast further in neutral than with the clutch down? The wheels are not having to spin the driven side of the gearbox and the clutch plate.
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Originally Posted by Bluepete
I am lead to believe that with many modern engines, when the road speed is above the engine speed, the injectors turn off.
In other words, on downhills, just take your foot off the gas, leave the engine engaged and the fuel stops flowing. This gives higher mpg than coasting as the engine needs fuel to idle whilst coasting.
Pete  |
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Originally Posted by punyXpress
But wouldn't you get engine braking?
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Correct, these guys want to coast as far as possible, so engine braking is not desirable.
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Originally Posted by Ed
What if the car's automatic  It's a while since I had a manual car. I don't like 'driving' in neutral as the brake servo don't work. |
Just plan ahead and avoid your brakes. You burn fuel to generate speed, then when you brake you take that kinetic energy and turn it into heat. Even in an automatic, if it's modern FI, a closed throttle will shut off the injectors.
When you hit the 1/2 mile sign exiting a motorway, move over to lane 1 gradually loosing speed with your foot light on the throttle, when you see the 300 yd sign, foot off the throttle completely, and let the car slow down naturally. You'll be down to 50 mph or so by the time you hit the slip road and usually down to 15-20mph by the end of the slip don't touch the brakes unless you have to stop at the end.
With the likes of roundabouts and junctions, throttle off as soon as you see it, earlier if it's downhill, and let your car slow gradually, just the same as above. If you can watch the traffic and anticipate ahead as you approach the roundabout or junction, you can try and time it so that you don't have to brake at all, you arrive just as there is a gap in the traffic flow, and you accelerate gently away again.
Your average MPG is also directly related to how far down your foot is on the accelerator pedal, go for a 'light touch' approach with your foot, only using just as much throttle as you need, and you'll use less fuel.
Another trick with an auto box is if your feel it's holding a gear for too long when accelerating, lift your foot slightly as though you were up to the desired speed, and it'll change up a gear, then reapply throttle gently to get back up to the speed you really wanted, but not hard enough to make the box kick down again.
It'll all drive the people behind you nuts, but who cares if you are saving money.