Julian Edgar has posted the first of a two part series about an electronic project device called "FuelSmart" that he's impressed with:
Quote:
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If you have a manual transmission car and the engine uses a MAP sensor, this device can improve your fuel economy by up to 15 per cent.
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To be clear,
it's not a vehicle mod, but instrumentation using vehicle sensors to help the driver use the go pedal smarter to save fuel.
See:
FuelSmart - Part 1
Essentially it monitors throttle position (via the TPS), and engine load, via manifold absolute pressure (MAP) sensor. If the unit detects
inefficient engine operation, it lights up a red LED. EG, under low load and a mostly closed throttle. The LED is the driver's reminder that s/he can get better economy either by giving it more gas, or increasing load (upshifting) if you're trying to accelerate or climb.
Or if you're approaching a stop, it's a reminder to fully release the throttle and go into DFCO mode (Deceleration Fuel Cut Off), rather than very lightly motoring along in a very inefficient engine operating range.
The article also explains the pros/cons between this device and a simple vacuum gauge.
My main criticism with the piece is it muddies the waters about what "pulse and glide" is (discussion of BSFC often includes a P&G description, as this one does). It essentially describes "Pulse and DFCO",
not Pulse and Glide. DFCO necessarily occurs in gear, with engine braking slowing the vehicle as a result.
DFCO is not a true glide. A true glide occurs in neutral and will out-distance DFCO.
Engine-off gliding will beat DFCO every time in terms of better fuel economy.
Full details:
FuelSmart - Part 1