Accelerating for good fuel consumption.

[JockoT]

I am struggling with trying to get the best out of my little engine under acceleration. I seems that no matter what I do I find that the instantaneous figure drops down into the low 20's (or lower) as soon as I open the throttle.
I have tried monitoring the Throttle Position Sensor, but the values the ScanGauge show seem to jump all over the place. It varies between 12 and 85 but trying to keep it up near 85 without reaching 85 is almost impossible.
My question is, can I use the loop sensor? If I keep the system running in Closed Loop, with the throttle as wide open as I can to keep it in Closed Loop, is this the best acceleration for fuel economy?
I do not allow the revs to exceed 3000, trying to keep them around the 2500 mark. Should I rev a bit higher, so that when I change gear the revs drop to nearer the point of best Brake Specific Fuel Consumption, instead of below it?

[Fat Charlie]

Let her rip- harder acceleration means less acceleration.

The sooner you're up to cruising speed, the sooner you're out of the bad instantaneous mpg. Even if you can mitigate it somewhat, it doesn't beat cruising mpg. Get into the throttle more sou you can get out of it sooner.

Your short trip mpg will thank you long before you get where you're going.

[ecocruze]

Charlie that doesn't work for my Cruze. I feel for NA cars that's a good fit but anything with a turbo seems your best bet is to accelerate just out of boost. I have tested my acceleration many times and my little turbo eats gas.

[JockoT]

Originally Posted by Fat Charlie

Let her rip- harder acceleration means less acceleration.

The sooner you're up to cruising speed, the sooner you're out of the bad instantaneous mpg. Even if you can mitigate it somewhat, it doesn't beat cruising mpg. Get into the throttle more sou you can get out of it sooner.

Your short trip mpg will thank you long before you get where you're going.

As you are an experience Hypermiler, driving the same make and model as myself, I will certainly give that a try. My Jazz is the base model, difference is it has the 1.2 litre i-DSi engine. But being naturally aspirated I will certainly try that.

[t vago]

Originally Posted by JockoT

If I keep the system running in Closed Loop, with the throttle as wide open as I can to keep it in Closed Loop, is this the best acceleration for fuel economy?

Yes.

Furthermore, you should try to obtain a torque/HP dyno graph of your car's engine. Barring that, try to find the RPM point where your engine torque starts to drop - that's where you want to upshift.

[JockoT]

I have the Power/Torque curve here.

[t vago]

So, looking at that graph, I'd probably try to keep my engine speed between 2500 and 4500 RPMs while accelerating.

[JockoT]

I've never ever rev'd it past 4000, but I'll give it a try.

[ecocruze]

Originally Posted by JockoT

I've never ever rev'd it past 4000, but I'll give it a try.

Lmfao punch it grandpa eco gotta get the carbon out of there at some point.

[JockoT]

I am not against revving a car. Even my Volvo was red lined on a regular basis. Just the Jazz has a gearbox whine (model trait - input shaft bearing), and revving makes it sound like the cogs are coming through the floor to meet you. Not worth fixing though.