SGII what 4 parameters do you monitor most?

[mwpiper]

I'm going to concur with jonr at post #8. When I got my ScanGauge I found I was driving too softly. Not only does it increase the likelihood of incoming fire from the people behind you, but it keeps you in low gear longer. I don't floor it (my gas peddle has never known the floor), but I move out aggressively to get through the first two gears. I can watch the instantaneous MPG climb with each gear. Even going up hill, I push it to get into third gear. When you average the longer distance at low MPG, it drags down the total.

PS: FWT FIA to monitor new Hot Air Inlet
TPS to control foot
MPG to see how the foot is doing

[azraelswrd]

update:

MPG
AFC (Avg FE for Current trip)
FWT
TPS

my MPH and RPMs are fairly consistent from the SGII and my instrument cluster

[Q1000]

Fwt Fia
Lph Lhk

[jonr]

It would be nice if it allowed you to load in a BSFC chart so that it could display BSFC.

Or use an accelerometer or GPS input to derive it (with long term averaging to account for hills).

[rjacob]

MPH, MPG, TPS, and either water temp or GPH.

[97Cavalier]

For myself I use:

RPM - MPH
MPG - TPS

With my 4-spd auto trans I tend to keep the TPS <= 20 or 25 depending on how much traffic is behind me and on the highway I've found that my '97 Cavalier gets the following mpg's.

Without A/C: TPS of 10-12 will hold a steady speed on the flats and at 60mph I can usually average between 45mpg - 50mpg.

With A/C: TPS of 15-18 will hold a steady speed on the flats and at 60mph I can usually average between 31mpg - 35mpg.

Jeff

[azraelswrd]

I try to keep my TPS around +4 and +6 above idle for FE while trying to stay between 45 and 55mph.

[PA32R]

Originally Posted by jonr

A really light foot with slow acceleration hurts FE*. People would be better off with a BSFC readout during acceleration. Preferably one that would display negative numbers when you hit the brakes.

* you get good instant FE numbers, but it also takes longer to get up to speed. So it is misleading.

I don't know about that. I don't have an engine map for my vehicle but I assume it looks generally like the ones I've seen. It's clear that ultra slow acceleration doesn't utilize the most efficient areas of the map, but there's another factor.

Looking at the vehicle as the system boundary and outside as the environment (that is, ignoring the rotating masses in the drivetrain, etc.), fuel is used to do two things: overcome resistance (rolling, aerodynamic drag) and to add kinetic energy during acceleration (assuming level ground). If I accelerate slowly, that portion of fuel that goes to add a given amount of kinetic energy is burned over a greater distance - the calculations are quite easy and I can show it if anybody wants. But if I accelerate at half the rate, I'll go twice as far to get up to any given speed and that portion of the chemical potential energy that is converted to added kinetic energy is used more efficiently in that sense.

Combining this with bsfc on the engine map turns out to be a fairly thorny mathematical problem, though I'm working on it using a "generically" shaped engine map with a few tweaks to accurately represent those few spots I know about on my vehicle. Maybe somebody here has modelled this? It's a problem in numerical integration.

Sorry to hijack the thread.

[MKL]

RPM MPH
MPG Lod

[NeilBlanchard]

Hi,

I used XGauge to map the average MPG (normally in the Trip selections) to be available in the Gauge options:

AVG TPS
MPG fWT