fuel economy test DA9 LS integra

**Runt** · 09-01-2008 07:43 PM

hey guys

have you ever turned upsided down a full 2l bottle of water and found that it takes more time to empty out the first half than the second half? try it, full bottle will always take longer to empty to half way than a bottle filled to half way and emptied at the same time, same happens to your fuel tank, its about vacuum, the more air you have in a bottle the easier it is for the remaining liquid to get out..

also to add to this when your car gets to half tank you have more air in the tank, that allows the fluid to shake and swirl about more than it would in the confinements of a full tank, making more gas fumes and more pressure...

with one way out its actually trying to push past your pump making your car less efficient, put in a new pump, it should better this. but not eliminate it.

it happens to every car, older cars its more noticeable though.

i had little to no toys growin up.. plenty of bottles though!

cheers will

**ACTI0NMAN-1** · 09-01-2008 09:08 PM

Originally Posted by Runt

hey guys

have you ever turned upsided down a full 2l bottle of water and found that it takes more time to empty out the first half than the second half? try it, full bottle will always take longer to empty to half way than a bottle filled to half way and emptied at the same time, same happens to your fuel tank, its about vacuum, the more air you have in a bottle the easier it is for the remaining liquid to get out..

also to add to this when your car gets to half tank you have more air in the tank, that allows the fluid to shake and swirl about more than it would in the confinements of a full tank, making more gas fumes and more pressure...

with one way out its actually trying to push past your pump making your car less efficient, put in a new pump, it should better this. but not eliminate it.

it happens to every car, older cars its more noticeable though.

i had little to no toys growin up.. plenty of bottles though!

cheers will

I understand what you are saying, but the actual pressure in the tank isnt enough to make a drastic effect on the fuel economy. infact it would be so minute i doubt you could record it.

**Spoon DA9R** · 09-01-2008 11:36 PM

the fact that the fuel that leaves the tank is so much less than water that POURS from a bottle...i seriously double it'll be noticeable at all..ur injector will still pump the same about of fuel whether is full or half full tank...

**Runt** · 11-01-2008 07:56 PM

meh....

I realize this, bottles of water, just a visual aid...

either way, my car is completely stock mechanically, im getting on average 380k per tank on vpower, thats pretty poor.

i need to service it.. pump, fuel filter, air filter plugs, should make a difference.

does anyone have a proper explanation for the second half rapid use fuel mystery???

until i see other wise i dont think im far off.... i could be way off... which is more than likely the case!!

**aus91integra** · 11-01-2008 08:57 PM

change ur o2 sensor.. it will improve your fuel economy

**Spoon DA9R** · 15-01-2008 03:24 PM

Originally Posted by Runt

meh....

I realize this, bottles of water, just a visual aid...

either way, my car is completely stock mechanically, im getting on average 380k per tank on vpower, thats pretty poor.

i need to service it.. pump, fuel filter, air filter plugs, should make a difference.

does anyone have a proper explanation for the second half rapid use fuel mystery???

until i see other wise i dont think im far off.... i could be way off... which is more than likely the case!!

380?!?!? thats pretty bad man...get a look at it soon..i get around 480 average...

**DA9jeff** · 18-01-2008 06:42 PM

just wondering why some people use premium - I thought that our cars are tuned to run on 91ron (as it says in the handbook) and unless you advance the timing, there would (should) be no noticable difference to power. You may go a little further but seeing as the ignition is set to run 91ron (ie more retarded) it seems like a waste of money, espec if your only getting 380ks from a tank of premium!

ps I often run to 600kms and often have 5-6litres left, but my car is serviced regularly. (and im usually driving in the power band)

**JHMDA9** · 19-01-2008 08:47 PM

I get about 500 around town, with a bit of what they call "spirited" driving.

**EuroAccord13** · 19-01-2008 10:27 PM

I get 9.21 litres per 100kms now.. Up from my previous 8.19 LOL!!! That's about the same as my Euro....

**string** · 20-01-2008 02:12 PM

I get pretty much spot on 10L/100km, 80% city driving, 100% spirited.

You don't use the second half quicker, you're just being fooled by the gauge into thinking that half way means it's half full.

**Runt** · 21-01-2008 04:22 PM

Meh... 91 feels worse than it does on high octane... thats pretty gutless.
i got 450 once with heaps of freeway driving!

i guess 380k is pretty good for me considering i used to drive a turbo that would get me 300max!