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Scientific Journal?

| 01 September 2007

Aim: To investigate the change in acceleration, speed and other driving practices after adding a full tank of petrol to my car.

Hypothesis: The car will feel heavier, have a slower acceleration in standard driving situations, have a greater acceleration when rolling freely down hills, have a higher responsiveness to the clutch and make James happy when he looks at the gauge.

Materials:

  • Car, preferably mine;
  • Money, preferably yours;
  • Fuel Docket, makes it cheaper;
  • Road, with or without traffic;
  • Dead weight named Alastair.

Method:

  • Drive car until almost empty of petrol, get a 'feel' for it.
  • Visit petrol station, park next to empty unleaded pump.
  • Swear continuously while trying to remove the petrol cap (It's a bitch, ain't it?).
  • Fill up tank.
  • Pay for petrol.
  • Replace cap.
  • Drive the car out of petrol station.
  • Run car through a number of scenarios to test its 'feel' compared to before the tank was filled with petrol.
  • Stop driving like an idiot and go home

Results:

  • Car is distinctly heaver.
  • Engine revolutions are far lower than before.
  • Car is harder to accelerate.

Conclusion: The car is feels heavier due to the quantity of petrol filled in the car. Because petrol is slightly less dense than water, and I filled the car with 41 litres, I expect that the car has had 40 kilograms added to the weight of the car. It should be noted that in pre-testing the car had 80 kg of weight added to it yet no noted weight gain could be felt. This could be because Alastair sits in the front passenger seat, where the petrol resides at the very rear of the car. As the car is a front wheel drive, the car would have to be doing a greater amount of pulling to the petrol than to Alastair, who resides almost on top of the engine (he has long legs). This means that the car is pushing Alastair, where it is pulling the petrol. This is why a greater weight could be felt with the added petrol.

Adding petrol is a contributing factor for acceleration from a stopped position in two separate ways. The car was also noticed to have a far lower engine revolution with the added petrol. While an explanation for this is not known, it makes the car much more likely to stall when accelerating away from a stopped position. Also, the added weight of the petrol will slow the cars acceleration. This acceleration is the most noticeable difference in the movement of the car.

On a downward slope, the car is much faster to accelerate when the clutch is placed in (the equivalent of placing a car on wheels, with no engine). This is obviously due to the added weight of the car, as the same experience can be duplicated by adding my dead weight (Alastair).

It should be noted that my hypothesis was completely correct, except for it's higher responsiveness to the clutch. The car is clearly more possessed when filled with petrol, this could be because all the dinosaurs don't like being in liquid form. Due to these observations, it is clear that the car uses less petrol when it has a full tank, mainly due to the lower engine revolutions. It is also clear, that I prefer a full tank of petrol.

People are welcome to duplicate this experiment by filling my car with petrol; I will gladly accept all the petrol you want to give me to continue gathering results for this ongoing experiment. Government funding will also be accepted.

EDIT: Al ain't as fat as I first thought he was... All you potential partners should know he's actually 75kg...

3 opinions:

Anonymous said...

NEEERRRDDD!
that is all!
catch

Anonymous said...

your car probably revs lower when it has a full tank because it does not have to drive things such as the fuel pump as hard as when it is almost empty because the petrol will force itself down the line because of the weight on top of it. i dunno how much difference it would make but its a possibility. also may depends on your aircon as well because it has to drive the compressor. long comment but hey im will to contribute to science.
- JD

Anonymous said...

and wen does al become a read DEAD wieght?? lol
maybe thats what the thump was haha
have fun driving!!
xx