Fuel Consumption.

[stono]

I recently brought a commodore vy lumina and am getting around 14.5-15.5l/100km. I was wondering what everyones else VY fuel consumption is because the redbook site says fuel consumption is around 10l/100km. I don't drive it excessively hard or fast.

This is my first commodore and was wondering if this is excessive or normal.
Cheers
Stono

 

[PIMPIN]

I think that sounds normalish....10L/100km would be for highway driving I assume..?

 

[Astranomical]

If i'm correct our VY gets about 10 - 15L/100km

 

[peeete]

in my VX i work on a system that $10 = 100klms

it actually works out about right.

just checked the odo and i got about 210 from $20 @ 94c per litre = about 21L

 

[Rippa]

My consumption

My VY Series I 6cyl Exec gets around 8.2L/100km over the 280k's between Gladstone and Maryborough in Qld averaging around 95kph (few towns to go through pulls it down from the 100-105 I set the cruise on) by the computer which seems pretty accurate based on my calcs. Around town I generally get 12-13. This is running various breeds of premium.

 

[peeete]

My VY Series I 6cyl Exec gets around 8.2L/100km over the 280k's between Gladstone and Maryborough in Qld averaging around 95kph (few towns to go through pulls it down from the 100-105 I set the cruise on) by the computer which seems pretty accurate based on my calcs. Around town I generally get 12-13. This is running various breeds of premium.

so you think you actually think u get better consumption on premium?

 

[Alloytec]

You will get better fuel economy on premium..

the more octane a fuel has, the slower it burns. the less it has, the faster it burns.

a 'fast bang' (low octane fuel) creates less heat because it's not burning for so long, expands quickly after said bang and combined with advanced timing can cause pinging.

a 'slow bang' (high octane fuel) creates more heat (the flame lasts longer - although a litte cooler), expands slower and combined with conservative / retarded timing causes VERY sluggish performance.

therefore, to make the most out of a slower burning (high octane) fuel, you will need to advance the timing to get maximum compression and maximum combustion expansion (generally 50% expansion after the spark is when the pressure increases exponentially - that time is measured in milliseconds and nanoseconds) happening at the same time to maximise the amount of force applied to the top of the piston.

okay. that's the theory out of the way - and the point that a lot of armchair performance enthusiasts will argue.

fact of the matter is, at high revs, any engine can benfit from a slower, more complete burning fuel to reduce the combustion pressure's tendency to go everywhere but where it should - squish up around the spark plug (part to do with volumetric efficiency). if the intake charge doesn't squish properly and you get a nice fast bang with the engine's vacuum pulling the dizzy around to what might be 5º advance, then you get uneven pressure across the top of the piston. uneven pressure means less torque and less efficiency.

a slower burning fuel in the same engine with poor squish will spread slower due to the slow bang. this will allow the pressure to spread more evenly across the piston and while not as fast a bang to push things along, the pressure is even and complete and therefore more torque is generated.

around the city, 98 is useless. you're better using 91 because your engine isn't going to see any kind of prolonged advanced timing or high revs.

head out on the highway (lookin' for adventure...) and the difference is instantly noticeable.

 

[Rippa]

My consumption

Yep according to the trip computer and my calcs I get more k's per litre... on standard it generally goes up to about 8.4 L/100. As explained by alloytec above

That doesn't necessarily mean it's cheaper as the spreadsheet below shows with fuel @ 90c & 95c (copy it somewhere else to see columns)

L/tank L/100km km/tank $/L $/tank $/km
70 8.2 853.65 0.95 66.5 0.0779
70 8.4 833.33 0.9 63 0.0756

So on these figures the premium is actually 0.23c per kilometer more than the regular which over a year of 30000ks will cost me $69. This is based on my highway figures, round town would be different, as alloytec pointed out premium makes much less difference. It also ignores any other benefits the premium might give such as cleaner fuel lines, less emmisions etc.

Of course if I could find the mythical servo where premium was only 2c more or a premium that game me 0.5L/100 advantage it would be a different story.

70 8.2 853.65 0.92 64.4 0.07544
70 7.9 886.07 0.95 66.5 0.07505

I am on the highway most weeks so for 70 bucks a year I use premium... it just feels better.

 

[calaiscruise]

VYII Calais 5.7 V8 Economy

I'd like to share my fuel economy readings for comparison.

I recently purchased a 2004 VYII Calais 5.7 V8 (obviously an auto) and am well please with my purchase...well done GM Holden.

Whilst I knew it would be a bit thirsty, it never gets economy like the AS (Australain Standards) specs you see listed in motor magazines, or on Redbook eg. Hwy 8.5L/100km, City 13.5L/100km. ( I would love to find out the exact testing procedure used ).

I am a normally conservative driver and travel a mix of light traffic 60 & 80 kph zones, and some 90-110 kph zones, I average 14-15L/100km. This is for light acceleration keeping up with the general traffic flow. Of course pressing heavily on the "loud pedal" sends the fuel usage into the clouds

As the Calais has a multi-display trip computer, I usually have the average economy display on, and notice whilst cruising on a freeway section of 100-100kph, it will sit on about 11-12L/100km...or in a 90kph section it can drop to 9-10L/100km.

I'm sure this is normal, as it's recently been serviced, but would be interested to know othe peoples figures.

I have long term plans (having done some internet researching) to install a cold air induction kit, K&N air filter, which I would expect to power, economy and bottom end torque....any suggestions?

p.s. I am impressed by the communtiy spirit to share and solve questions from members in this forum, well done people

 

[RKZ234]

Fuel Economy

If you set the cruise at 102km/h, take it easy when overtaking, you can get fuel economy down to well under 7lt/100 km in a V6.

I've done Coonabarabran (NSW) to Sth East Suburbs of Melb on the one tank of fuel and achieved 6.72lt/100km

I've achieved these figures twice, once in a VY S auto sedan (achieving an avg 6.72lt/100km and a VX Exec auto sedan achieving an avg 6.75lt/100km, so the minor difference is simply explained by traffic conditions.

I know I could do better than that if I was willing to cruise a few k's slower than 102.

6.72lt/100 km is better than 41mpg in the old language!!!

P.S - calaiscruise, our VX S/C V6 was getting 13.5 lt/100 km economy at best on a trip with 10,000 km on it. We had used Premium from brand new. I installed a pod filter (from D&T Performance Adelaide) and instantly got 8.2/100km on a trip from Melb to Toowoomba. Around town economy has improved by about the same margin of 5lt/100km. Comparing cost vs result, a pod is EXCELLENT value for money and very easy to change. Plus the s/charger spins up quicker supplying more power and delivering it more smoothly. By my calcualtions, having driven a further 60,000km since fitting the pod, it has saved us approx $3000 in fuel costs, meaning it paid for itself after about 7,500 km!