Saving gas - on a familiar (lightly travelled) roAd
About five years ago on the death of childless step-uncle's wife, we were worried about his safety, as he'd had three hip replacements and despite suffering substantial pain in back, hip and leg, was, in his mid-80s, keeping some beef cattle in the barn. With a partner in the house to call help if he fell into a snowbank and couldn't get out, help was summoned. No watchful partner - no call for help. And he wouldn't carry one of those buttons on a string around his neck that he could use to call for help. So I stayed here with him for a couple of months, until his cattle went to pasture.
A couple of years later, when uncle died, his executors wanted to have the place look occupied, so I travelled from the edge of the city on mostly rather quiet roads, often late at night, to sleep here and spend time. The trip was 20 km. (12.5 mi.) according to my little Dodge Colt's odometer (old Ford van said it was 18km., plus a bit, I think).
Travelling daily, I became familiar with the minor variations in gradation of the road (though often at night made it slightly more difficult). My little Dodge Colt had 1.5 litre engine, and a standard tranny, and I would push in the clutch and turn the key off when running downhill, or to a "STOP" sign, turning the key on and letting out the clutch to re-start at a low point (or just as I arrived at the sign ... and with some practice, if there is no traffic, one can often arrange to be going quite slowly on arrival at the sign (or traffic signal, in the city).
I found that I was able to coast for 16.6 km. of that 20 km. journey ... just could not make 17.0 km! If anyone had told me that I could have achieved that proportion (over 80%!) of the trip with engine not running ... I would have said that they were crazy!
I didn't arrange it most efficiently, though, for often I'd be travelling quite slowly at the low point on the road, and would push the throttle rather hard, in third gear rather than fifth, in order to achieve speed while travelling up a rather short upgrade, in order to turn off and coast down the next downhill portion.
The most effective system would be to keep the gearshift in fifth gear throughout, and to avoid pushing the throttle hard while travelling up the rises: gentle throttling is way the best for gas saving.
Didn't do it much when travelling using the '80 van - automatic transmission - too much using of the starter. You know what starters cost, even at the recycler's ... even supposing that, on that older, simpler van, I might have been able to install it myself.
Some police persons that I've asked haven't said that coasting is illegal ... but they say that the driver is to be in full control of the vehicle at all times.
I couldn't have asked the driving examiners while travelling on my three road tests ... but I should have asked them before the trip, or on our return.
The driving instructor said that coasting's not permitted.
While it's somewhat more difficult to turn the steering wheel while the engine's off, I have strong arms and could compensate. And I can have the engine running in less than one second.
I had residual pressure in the braking system to allow for two pushes, sometimes three.
I only turned the ignition part way off - eough to leave the radio running, and not lock the steering wheel.
Have a frugal week, everyone.