Sydney to QLD on one tank.

[vt1538]

Drove from Alice to Dwn & back over christmas.14L /100km at 150. But got 13.7/100 at 155 kmh. Not sure if it was a tail wind on the way back that gave the slightly better economy.

 

[Marty's_SV6]

Just came back from a trip to Melb and on the way back to Syd in my dads VY Acclaim S2 we got final figures of 8.0/100 not bad at all.
My SV6 got figures of 7.6/100 driving back from Canberra and had only done 1000ks at that stage.

 

[Hairy Eater]

i'm sure you blokes will loose economy while travelling the outback..... 1 especially during daytime cos of hot air... 2 cos of dry humidity.... i live there and know how hot the air gets during the day... i just bought VX a few weeks ago but havent been on a trip..... after i seen and read about the shitty IRS tyre probs i sold it today.... i like the Commy but not sure which model to get.....

 

[HSVKEV260R8]

Hot air can make minimal difference usually, I was driving in 35-40 deg heat in Nthrn NSW last year in the Clubby R8 and still got under 10l/100kms out of it.

 

[vt1538]

Thats at 110. My freinds car got 12l / 100km at 150 with the same kays as mine.

 

[Fekason]

Two sides to heat.

i'm sure you blokes will loose economy while travelling the outback..... 1 especially during daytime cos of hot air... 2 cos of dry humidity.... i live there and know how hot the air gets during the day... i just bought VX a few weeks ago but havent been on a trip..... after i seen and read about the shitty IRS tyre probs i sold it today.... i like the Commy but not sure which model to get.....

On the one hand, higher temperatures may lead to heavier use of aircon, and have an adverse impact on fuel economy.

On the other, however, higher temperatures effectively give a higher density altitude. That equates to less power available but also less aerodynamic drag at a given speed, i.e. lower power required to maintain the given speed. In theory, fuel economy in a modern fuel injected engine should be slightly better at higher temperatures.

That was not the case in the past with carby engines, for which fuel flow was generally dependent on intake air pressure rather than mass air flow.

 

[familyguy]

Just came back from Taree to Sydney in my VYII Exec (auto) with wife and son and bootload of gear, aircon most of the way both up and back, 655km at 8.8L/100km. I think the magic mark is 2000RPM in top to keep the consumption down. I find if I use the cruise at 115 (giving me about 2100RPM) I cant get less than 9.5L/100km highway style. I know, only an extra 700ml of fuel for 100 long km, but hey...figures are good.

 

[BottFodder]

Agreed... 2000RPM seems to be the "sweet spot" for Ecotecs. Maybe a 100 RPM or so less.

Do any of the ECU experts on the forum know where the V6 is achieving the best volumetric efficiency?

On the Aircon thing - I noticed that when my VYI is stopped the trip computer shows 1.9L per HOUR with the Air on. Turn it off and the number drops to around 1.6L/hr. Does this mean that Aircon costs .3L/hr to run. I realise that raising the RPM above idle will change this. Maybe I should take some readings....

Cheers

BottFodder