[Geezer]

I'm possibly the only person in this thread that has actually done this with a real-time MPG meter.

Oh yeah? I made my own digital MPG meter and stuck it in my VW in 1974.

[wolfekeeper]

Sure, I'm not saying that, sounds fun, but a 1974 VW probably didn't have a fuel injection system, this cut-off trick is done by the fuel injection system.

I used to routinely do this trick on my beemer, I also did mild hypermiling techniques including this one with it during the tanker strike; a 2.7 liter automatic is not the best type for that though, but it did seem to work!

[CliffordK]

I know that my old 84 Renault Encore had an electronic idle speed adjustment screw...
Until something fouled up with the system, and I replaced it with a bolt.

Anyway, I think the car had some kind of electronic in carburetor injection.

[peppercorn]

I'm possibly the only person in this thread that has actually done this with a real-time MPG meter.

Good to hear it! Shame ya beemer was an automatic though - at least in economy terms.  Some ecomodders go as far as fitting an injector kill-switch - so taking manual control of their fuel feed. It can apparently be of use if using the Pulse & Glide style of motorway driving (if you're courageous enough to do it!).

[Geezer]

Sure, I'm not saying that, sounds fun, but a 1974 VW probably didn't have a fuel injection system, this cut-off trick is done by the fuel injection system.

Yes, it had a carb, but it actually did have a fuel shut-off solenoid (althought that was there to make sure the engine would stop when you turned off the ignition!)

[wolfekeeper]

I'm also having range problems.  I was getting 35-40 miles this summer.  But, this winter, the range seems to be plummeting to under 20 miles  []

I think all battery techs. suffer from reduced efficiency in the cold (something to do with increased internal resistance perhaps?).
What you need is some nice low-value fuel (in terms of capacity to do useful work at cost) that is onboard simply to warm the batteries and the cabin.  The simplest vs cheapest heater would probably be Propane, but it's hardly in keeping with the electric 'values'.
I reckon Torrefied Wood (think efficiently produced charcoal) is a pretty interesting and underutilised source of cheap heat (and even mech work) especially if you want to move said source around (ie. vehicles).

You can also use electric heaters when plugged in, and the battery may be able to power the heater itself when it's not (with some reduction in range). That's how the Tesla works, it has the same potential problem.

[peppercorn]

You can also use electric heaters when plugged in, and the battery may be able to power the heater itself when it's not (with some reduction in range). That's how the Tesla works, it has the same potential problem.

Yes, Tesla have gone for the simplest solution to cabin heating; with the Tesla being marketed as a sports car (esp. as it's a two-seater, usually with a soft top) I doubt the average driver is necessarily too worried about a heater anyway!
The thing to remember is electricity is pretty much the highest value energy source there is - so wasting it on making low-value heat seems rather a crime really!
OTOH, I can see that a (mains) plug-in heater option both to pre-heat the battery-box (improving range) and cabin pre-heat (or even a small onboard P.C.M. module) could represent the best compromise between fuel value and simplicity.
Personally I'd still want a small butane heater or similar for those longer journeys though; at least for a car with a 'proper' tin roof [].

[Geezer]

Personally I'd still want a small butane heater or similar for those longer journeys though; at least for a car with a 'proper' tin roof .

Ewe could always take a hot-water bottle with ewe.