Squeezing extra MPG out of P&G (EOC WHILE KEEPING THE CAR ON??)

[bestclimb]

Jedi,

An MPGuino screen that has instant GPH or total fuel consumed will give you fuel data without needing any distance reference.

Looking at the wiki the "custom"

1. "Custom":
| MG Instant MPG | S Instant Speed |
| GH Instant GPH | C Current MPG |

or

8. "Tank":
| MH Tank MPH | MG Tank MPG |
| MI Tank Miles | GA Tank Gallons |

and

9. "EOC mi/Idle gal":
| CE Current EOC Miles | G Current Idle Gallons |
| TE Tank EOC Miles | G Tank Idle Gallons |

if you do some resets while getting your data the tank gallons will give you how much fuel you used durring each run, or because you are not giving the MPGuino any distance information it will assume that any fuel used is "idle"fuel. so idle gallons will give you how much fuel you used during each run.


From what I remember MPGUino will need 12v(battery +), 0v (ground) and a Fuel injector signal wire.

The two cars (escort and civic) I had my Guino installed in I tapped the signal wire near the ECU.

[vskid3]

I would hook up the VSS to be able to see the actual MPGs. Then you can account for any differences in speed between your test runs.

[bestclimb]

I think Jedi's method without the vss is solid enough. Once he gets GPH(gallons per hour) on the MPGuino calibrated to match the GPH on his OBDII derived fuel consumption instrumentation he will have a solid comparison with what the actual fueling of the engine is vs what the computer is reporting. If those numbers match (or show a strong correlation) on a few runs bliping and not bliping the throttle it will demonstrate that the data he gathered earlier is good rather than an artifact of method he used to get the data.

[maczo]

Thought I'd chime in - I noticed the same effect in my car (using Toque Pro), but while it reports zero flow the moment I lift off the pedal and clutch in, it consistently continues to show zero flow a second or two AFTER the RPM is stabilized at idle. Can't imagine this being true.

[jedi_sol]

90% confirmed!

Hooked up mpguino this morning.

Set to "custom" to display gallons per hour fuel usage

Display shows 0.00 gph for a split second after I step off the throttle!

Per bestclimb, I will calibrate the mpguino gph to match scangauge gph.

I'll also redo my test runs to verify amount of fuel used for both methods

I'll post a YouTube video later tonight.

Maczo, have you tried setting torque app to "read data faster?"

[jedi_sol]

Here is the video. Mpguino has not been calibrated yet, this is just to simply show that the fuel injectors cut off when I step off the throttle.

Fuel injector cut off with pulse and glide: Fuel injector cut off with pulse and glide - YouTube

sorry for the shaky camera this suspension is really stiff

[serialk11r]

So what you're telling me is that if I tap the throttle and rev the engine a tiny bit, that should use less fuel than idling? That is one of the strangest things I have ever heard...I don't have a good enough OBDII scanner to detect this, but I think it might not work on older cars with a less intelligent ECU. My ECU doesn't seem to cut fuel ever below uh, 1300rpm?

[Fat Charlie]

If you can pulse & glide a whole car, it makes perfect sense that you can pulse & glide a DFCO engine.

[maczo]

Yes, I'm using the "faster read" option, maybe the hardware is slow or something else is at play here. Anyway, it reports zero flow waaay longer than what you have in the video above.

And about the video - is the zero flow period really long enough to make the throttle blips worthwile?

[jedi_sol]

I have the mpguino calibrated, but have not got around to testing yet because the mpguino only goes to 2 decimal places. The amount of gas used during idling is very small, so it's hard to find a stretch of road long enough for me to see the differnces between p&g vs throttle blip. I'll continue searching.

More updates:
I recently filled up and got 27.69mpg using my throttle blip technique! BEST TANK EVER!

My previous best tank (using eoc and all aero mods installed) is 27.56mpg!

My previous 3 tanks using p&g only I achieved 25.1-25.4 mpg.

Serialkiller ,
Yes, I agree, older cars with older ecus may not have the throttle fuel cutoff in their fuel maps. However this may simply be that not everyone has a good enough obd2 scanner to test my theory.

But if anybody out there wants to test my theory, I would help us figure out what cars work and what cars don't work

maczo,
I'm thinking this technique works best when doing p&g at highway speeds as the distance travelled during the 0.00gph is greater at higher speeds, thus out weighing the fuel used to initiate the blip, thus bumping up the mpg averages. I noticed even the sgii stops displaying 0.00gph at below 30mph.


So at least the proves that I'm not WASTING gas by throttle blipping.