Does this seem normal?

[sergei]

Here is more speculation on the topic running on low will lead better fuel economy:

1L or petrol produces ~ 6-7MJ of energy.
it takes ~13kJ to propel 33.5kg to 100kph (E=0.5*m*v^2).
in other words ~0.2% of said 1L of petrol or ~2mL.
So each time you accelerate full tank to 100kph it takes extra 2mL (or cc) of gas. Remember your injectors are capable of injecting ~ 210-290cc x4 per minute at full load.

Did you factor in that the chemical energy is produced in heat and sound as well?

Yes, hence 1L of petrol worked out 6.8MJ and not 34MJ that is released when it is burned.

[diss7]

Here is more speculation on the topic running on low will lead better fuel economy:

1L or petrol produces ~ 6-7MJ of energy.
it takes ~13kJ to propel 33.5kg to 100kph (E=0.5*m*v^2).
in other words ~0.2% of said 1L of petrol or ~2mL.
So each time you accelerate full tank to 100kph it takes extra 2mL (or cc) of gas. Remember your injectors are capable of injecting ~ 210-290cc x4 per minute at full load.

Did you factor in that the chemical energy is produced in heat and sound as well?

Yes, hence 1L of petrol worked out 6.8MJ and not 34MJ that is released when it is burned.

So based on your maths, what extra fuel would be required if the car was twice the weight?

[sergei]

Here is more speculation on the topic running on low will lead better fuel economy:

1L or petrol produces ~ 6-7MJ of energy.
it takes ~13kJ to propel 33.5kg to 100kph (E=0.5*m*v^2).
in other words ~0.2% of said 1L of petrol or ~2mL.
So each time you accelerate full tank to 100kph it takes extra 2mL (or cc) of gas. Remember your injectors are capable of injecting ~ 210-290cc x4 per minute at full load.

Did you factor in that the chemical energy is produced in heat and sound as well?

Yes, hence 1L of petrol worked out 6.8MJ and not 34MJ that is released when it is burned.

So based on your maths, what extra fuel would be required if the car was twice the weight?

To accelerate 1.3t to 100kph is required ~0.5MJ, or ~0.07L of petrol (~70mL).

BTW it does not matter how fast you do accelerate. What it matters is when you accelerate you need to have engine in it is top efficiency range and that equates at ~3/4 of throttle for petrol and a lot less for diesel (since no compression losses on that).

[gepsk8]

i hate that people still fill their cars with $20 gas, (back in day) it just not same as when gas was 89 cent litre, people need starter putting $30 or $40 in for same effect, just remember time filling up pay is so close if put $20 or $40 in, maybe 4 mins in it, as if you go back put $20 cost more in fuel (stop starting) and your own time like 10mins.

and cant talk about fuel in $ need talk about litres.

sounds like car need love, plugs, lead, cap, rotor, change oils, Filters.

oh yea, 4age one of those Wynn's carbon inlet clears will help to clean all shit out of inlet manifold, will help bit gave me 20 extra K's to tank when i did it

maybe injector check for spray pattern

[FYADUP]

Thanks for the imput guys - some more helpful than others.

allencr & Sergei - Im sorry if it seems that way, but as I mentioned I wasn't in the situation where I could do it. I was in the middle of nowhere unfortunately. But thought it might be useful to put it up anyway?

gepsk8 - I understand what you eman, but I don't always have the money to do it at various times - not always enough to fill it up anyway.

Will do another full to full test and see how we go...

Jason