How low can you go? (fuel economy)

[leelee]

so im averaging between 8.5-10l/100k's... the 8.5 was full highway drive
and im not exactly lightfoot ay... be interesting to see if it drops after i service him this week

 

[Cheap6]

Interesting thread. I think that it is very difficult to compare between different figures though, because driving conditions vary so much. eg. does 'city' mean sitting in stop go traffic or just urban driving in light traffic.

A few things to think about:

At idle a scan shows between 2.5-3.0 l/hour.

Having the engine cooling fan on draws 150W. (Divide that by an alternator efficiency of about 0.8 (80%) to get the engine power requirement).

Having the HVAC fan on '4' draws another 180W.

Having the A/C on does both + the engine power required to pump the refrigerant around.

At idle, A/C off, the engine is probably only making around 3-4kW, just enough to pump air into and out of the engine and overcome friction + alternator load.

 

[savage1987]

VN has run the last 400km at an indicated 9.3L / 100km

V6 auto 500,000+km

 

[Helicopter]

Just for future reference, so that no one else makes the same mistake, I ended up doing the fixup on this tune. The tune that came with his cam kit was burnt on an unmodified V6 memcal and that was the major problem, should be all fixed now and on the way home If anyone else has one of those cam kits. It would be worth checking the memcal to make sure it's not a on an unmodified V6 memcal

Back again,

I've been meaning to provice an update but foamy beat me to it. Yes, I can confirm that his new tune has improved the overall performance dramaticaly.
I don't know what the cam provider was thinking at the time, I suspect very little!

The engine is now very responsive, and goes quite well, still not a tire burner but that could be for a number of other reasons. The fuel consumption has dropped from a city average of 26 l/100 to about 21 l/100. Still rather on the high side but difficult to know what should be expected from an engine fitted with 218 cam.

I'm getting foamy to reduce the idle speed a touch because in drive, when you let go of the brakes the car takes off! I suspect the fuel consumption will also improve a bit as a result. Furthermore fitting a CAI will also add to the story.

Other than that, the tune is great. Oh did I mention Foam also fixed the problem I had of 1st to 2nd gear selection. Before I fitted the cam and memcal, the gear change was smooth. After fitting the cam and memcal, 1st to 2nd came in with a bang, regardless of throttle opening. I contacted the cam supplier and described the problem only to be brushed off, by saying its not the memcal and most probably a shift kit, which I new I didn't have anyway.

Now with the new tune, 1st to 2nd is smoooooth, and if I select 'power setting' it changes nice and quick. Shift kit my ars.....e:bang: This is the same guy who suggested I drill a hole in my butterfly to fix the wild idling problem which was clearly a memcal tuning issue, which Foam fixed anyway.

Lastly, Foamy suggested I run on 98, so yesterday I filled up with V-power for the first time in many months and it was immediately obvious that his tune likes this a lot!

Well done Foamy.:thumbsup:

 

[Cheap6]

That the engine tune affected the shift (presumably via TPS position) is interesting.

(Try tuning LPG very lean with a 4L60 and TV and see what happens to the shift ).

Has anyone done a back to back with the CAI? If fuel economy is the goal, perhaps a HAI may be better:

Throttleless Premixed-Charge Engines

 

[Immortality]

Back again,

I've been meaning to provice an update but foamy beat me to it. Yes, I can confirm that his new tune has improved the overall performance dramaticaly.
I don't know what the cam provider was thinking at the time, I suspect very little!

The engine is now very responsive, and goes quite well, still not a tire burner but that could be for a number of other reasons. The fuel consumption has dropped from a city average of 26 l/100 to about 21 l/100. Still rather on the high side but difficult to know what should be expected from an engine fitted with 218 cam.

I'm getting foamy to reduce the idle speed a touch because in drive, when you let go of the brakes the car takes off! I suspect the fuel consumption will also improve a bit as a result. Furthermore fitting a CAI will also add to the story.

Other than that, the tune is great. Oh did I mention Foam also fixed the problem I had of 1st to 2nd gear selection. Before I fitted the cam and memcal, the gear change was smooth. After fitting the cam and memcal, 1st to 2nd came in with a bang, regardless of throttle opening. I contacted the cam supplier and described the problem only to be brushed off, by saying its not the memcal and most probably a shift kit, which I new I didn't have anyway.

Now with the new tune, 1st to 2nd is smoooooth, and if I select 'power setting' it changes nice and quick. Shift kit my ars.....e:bang: This is the same guy who suggested I drill a hole in my butterfly to fix the wild idling problem which was clearly a memcal tuning issue, which Foam fixed anyway.

Lastly, Foamy suggested I run on 98, so yesterday I filled up with V-power for the first time in many months and it was immediately obvious that his tune likes this a lot!

Well done Foamy.:thumbsup:

thats fantastic. i'd go back to the original supplier with said info above and ask for a response.

 

[Cobez]

With my Foamy tune, my VS Senator (K&N panel filter with the high flow box and CAI), 3" exhaust, is currently sitting on 15.8L/100KM.

Not too shabby at all.

 

[savage1987]

^^ I hope that's around town or at least suburban.. my VR 5L can go down to around 11.5L/100km these days and I still think that's bad

 

[mazzstein]

With my Foamy tune, my VS Senator (K&N panel filter with the high flow box and CAI), 3" exhaust, is currently sitting on 15.8L/100KM.

Not too shabby at all.

dam mate thought it'll be abit lower

Stock Tune (as far as i know)
on the cluster it says 14.6L/100KM

CAI, 3" exhaust

 

[commsirac]

At idle a scan shows between 2.5-3.0 l/hour.
.

The instantaneous readout on my vx oscillates between 1.5-1.6 at idle at running temperature? are we talking about the same thing?