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fuel consumption/kms per tank - ve v8

CSP

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vnv8driver don't get pulled into a meaningless argument with commsirac. You can't reason with someone who no matter what thinks they're always right all the time.

He will always believe what he wants and think it's right. Like I have said, I have personal experience with many V6 engines (2 ecotec 1 alloytec 195) and two V8 engines (Aussie 308 and Chevy LS2) so I only speak about fuel efficiency from experience yet somehow I'm still wrong according to commsirac. Go figure...
 

Immortality

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not that it's relevant to the holden comunity but my old mans previous V6 (2.5ltr) mondeo is more economical then the identical mondeo with a 4cyl (2ltr) engine. i can say this with confidence because a gentleman at the same place of employment had said 4cyl mondeo so comparison was simple. indentical model, same year of manufacture etc.

not so relevant but my VN V6 uses only slightly more fuel then my families 2ltr nissan bluebird. again a car we owned from new and new (er) then (the VN). against my VN retuned for unleaded fuel and a few minor mods driven sensibly. if i wanted true economy i'd drive a 1.3ltr daihatsu (can't even spell it) but i like to know when i plant boot i'm going to move. power has saved my ass on more then one occasion. i'll never own a econo box (i don't even fit in em)
 

1991_Vn2nV

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^^^We get alot of people into work complaining about the economy on their 4 cylinder Toyota Camry's, yet all the V6 Aurion Drivers love their economy, with all the Aurion drivers stating lower economy than the 4 cylinder Camry equivalent.
 

commsirac

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the v8 runs at about 500rpm lower resulting in better economy.

.
Maybe you are correct about the rpm(however, it appears you havent comprehended how the number of piston strokes per minute in the current v6 and v8 are basically the same....but it doesnt just come down to reciprocating mass),Yet whatever you claim here is irrelevant to the real data out there. The aus fuel testing reveals otherwise(v8 drivers in denial again), v8s use more fuel to do the tests.....it is as simple as that. As I mentioned previously, if you can state a reason why the tests are flawed that no one has yet identified best you let everyone know now. All those silly members of the public buying smaller engine cars when they should be really buying v12s.....you are joking arent you?

Perhaps in your tafe course you had dynamic compression explained to you? At small throttle settings the effective compression ratio is often less than 5:1 seriously reducing engine efficiency.....they did explain engine efficiency increases with compression ratio? By operating an engine with higher throttle openings, dynamic compression increases, efficiency increases due to this, and other factors.....obviously a smaller engine has to be used if higher throttle openings are to be used.

No, these are not my strange ideas(I dont post rubbish....perhaps get a mechanical engineer to go through it with you), just well established laws of engine design that have been known for nearly a century
Have a look at these:
Welcome to Hefley Engine
(WO/1996/036800) HIGH EFFICIENCY VEHICLE AND ENGINE
 
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Hooray! Time for some physics!
There are 4 main things effecting the economy of a car.
1) Friction: The bigger the tyres the more grip. But inversely you will get more friction, which can be attributed to the mass of the car. Air friction, the car has to push the air out of the way. The faster you go, the more are you have to push through quickly. A (very) general rule is to go 30% faster, you need to double your power. This is the main thing that will effect a cars performance and why race cars are streamlined.
2) Auxilaries: Air con, heaters, subwoofers all increase the revs of your engine to support the alternator, and therefore guzzle more petrol.
3) conservation of momentum (newtons 2nd law): Force=mass x accleration. The heavier the car and the more you accelerate, the more force (pull) is needed. Cruisin at a constant speed you only have to overcome friction (newtons 1st law) slowing you down, but to speed up you need more power. hence why braking, accelerating..braking acclerating etc will ruin economy and why city driving is always worse.
4) Engine efficiency: Combustion engines are not efficient by any means. Energy is lost through heat (friction) and noise producing 35% efficiency (electric motors being around 85-90%).The bigger the engine, the more heat loss. the bigger the crankshaft, the more momentum needed to keep it idling. the more cylinders, the more petrol gets burned per rev. and of course you lose further power through the transmission, gear changes, poor tuning etc. Commsirac is right about the engine side of things.
So to conclude, this argument is stupid. There are too many variables and thats what the standardised fuel tests are for. To eliminate these variables. Unless you can account for all these factors, driving styles and terrains, you cannot compare data! I am sure someone nursing a V8 around in the country might get better economy than a hoon in a V6 who does city driving with the air con on and woofers blaring. bottom line, if you want to be more efficient, get a small motor, drive slowly, lose all the weight. i suggest a bicycle.
 

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^^^We get alot of people into work complaining about the economy on their 4 cylinder Toyota Camry's, yet all the V6 Aurion Drivers love their economy, with all the Aurion drivers stating lower economy than the 4 cylinder Camry equivalent.

i think the main reasons are:

1. Aurion and Camrys weight about the same.

2. V6 doesn't have to work as hard as a 4 to get up to speed.
 

CalaisRider

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.

IMHO fuel consumption carries huge variances. I have a cammed and modified L98.

I run 3.7 diff gears rather than the 2.92 stock version for A6.


On the highway I get between 8.5 and 11 litres per 100 depending on road conditions and speeds at the time.

Around town in Brisbane commuter traffic its commonly up to 19 litres per 100

And when I run Qld Raceway or Lakeside, the average is around 36 litres per 100..

PS: It idles at between 4.8 and 5.4 litres per hr... Stock was 1.8 to 2.2 litres per hr...


Pete
.
 

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How many of these threads do we need. Most people need to go take a cold shower :shutup:
 

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Hooray! Time for some physics!
There are 4 main things effecting the economy of a car.
1) Friction: The bigger the tyres the more grip. But inversely you will get more friction, which can be attributed to the mass of the car. Air friction, the car has to push the air out of the way. The faster you go, the more are you have to push through quickly. A (very) general rule is to go 30% faster, you need to double your power. This is the main thing that will effect a cars performance and why race cars are streamlined.
2) Auxilaries: Air con, heaters, subwoofers all increase the revs of your engine to support the alternator, and therefore guzzle more petrol.
3) conservation of momentum (newtons 2nd law): Force=mass x accleration. The heavier the car and the more you accelerate, the more force (pull) is needed. Cruisin at a constant speed you only have to overcome friction (newtons 1st law) slowing you down, but to speed up you need more power. hence why braking, accelerating..braking


acclerating etc will ruin economy and why city driving is always worse.
4) Engine efficiency: Combustion engines are not efficient by any means. Energy is lost through heat (friction) and noise producing 35% efficiency (electric motors being around 85-90%).The bigger the engine, the more heat loss. the bigger the crankshaft, the more momentum needed to keep it idling. the more cylinders, the more petrol gets burned per rev. and of course you lose further power through the transmission, gear changes, poor tuning etc. Commsirac is right about the engine side of things.
So to conclude, this argument is stupid. There are too many variables and thats what the standardised fuel tests are for. To eliminate these variables. Unless you can account for all these factors, driving styles and terrains, you cannot compare data! I am sure someone nursing a V8 around in the country might get better economy than a hoon in a V6 who does city driving with the air con on and woofers blaring. bottom line, if you want to be more efficient, get a small motor, drive slowly, lose all the weight. i suggest a bicycle.

.

WELL SAID THAT MAN!!!!!:yeah:

If I can go from 8.5 litres a 100 up to 36 Litres a 100 on the same car; there are certainly some variables to consider....:whistling

.
 

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you guys all must have Fu@@ed v6's my ve sv6 manual gets around 7.3-7.5 on the high way and about 9.3-9.8 in sydney.

i drive from Campbelltown to Bowral along the Hume ever day(mon-Fri) for work never seen above 7.5 and i go into the city cruise george st etc most fridays and saturdays. i get about 9.3ish might hit 10 if i red line it in frist and second off most sets of lights.

my car has extractors and a hi flow panel filter in the air box. getting it tuned this week end Dale at CHE tells me to expect 6.8-6.9 down the free way after then tune!!

your not serously calling that city, crumbletown/bowral, boo (for the mexican's.. seymore to woodonga but only 18k's apart)
try livo to bankstown 18kph average speed and i get 14/100..
but 8.9/100 livo to caldwell..
 
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