Tuning for maximum fuel economy

[brh26]

I am tuning a new Adventra. LTFT's are slightly negative (-1 average) and have no Knock Retard at WOT or Part Throttle. Everything is running properly. I am wondering if anyone has any suggestions on how I could proceed to maximise fuel economy rather than focusing on maximising power output?

Cheers
Brian

[Dirk_Diggler]

Buy a civic ;D

j/k

I have heard of people tuning for AFR's higher than 14.7 while part throttle and crusing.

The Aussies have a lean cruise that does this or something similar

[Screamn03]

The Aussies have a lean cruise that does this or something similar

This option is banned and thus disabled for the US market.

I'm thinking that maybe if you changed the Stoich A/F ratio on the Fuel Tab to something else like 15.5:1 or 16:1 you may be able to get away with it but I don't know how this will affect the operation of the engine because you'll have to adjust everything related to fuel to compensate. You might end up with problems because I don't know how you would just get it to lean out at cruise only. ???

[jimmyblue]

I think the stoich setting is supposed to be left alone,
it gets into too many things. But, you could go and
change the O2 voltage "pivot" value in the Engine>
Fuel Control>Open/Closed Loop Fueling>O2 Rich/Lean
vs Airflow table, lower by say 100-200mV, and the loop
would shoot for a lower O2 voltage average and make
you effectively leaner throughout closed loop. The
airflow dependence means you could "fade" this in or
out to stay away from ping etc. There's also an airflow
mode definition table you would want to figure out,
as far as where you do and don't want to lean out,
relative to what your car pulls on highway cruise etc.

[Billf6531]

Now that you mention air flow modes, what are the values / what are they related to?

[Chris@HPTuners]

I am tuning a new Adventra. LTFT's are slightly negative (-1 average) and have no Knock Retard at WOT or Part Throttle. Everything is running properly. I am wondering if anyone has any suggestions on how I could proceed to maximise fuel economy rather than focusing on maximising power output?

Cheers
Brian

Adventra's have lean cruise disabled (by setting the enable speeds at 400 km/h) and also the F/A subtarctor and all the enable multipliers are zero'd. For some reason Holden has disabled this for 2004 models.

You can enable it by lowering the enable speeds. email me and i'll send you a 2004 SS bin that has the 2003 numbers in it