full tank or half tank?

NewAgeSensitiveBoy SG

my 2 frens got conflicting schools of tots wif regards to fuel efficiency, so who is right?

A says he always pump full tank and try to maintain the tank as full as possible cos the more space in the tank means more space for the petrol to vaporise resulting in vapour loss of fuel. this way he says saves more money

B says he tries to maintain his fuel level the lowest possible and only pumps maximum half tank for his car. logic being more fuel means more weight means more power required to move the car.

So who do you guys think is correct?

spadeTwo SG

fuel is so light Rolling Eyes
and how litres can he pump ?
is the 2nd guy logic is right....
ask him go for fat loss programs

SBS9828X SG

if both are right, just get a smaller fuel tank Laughing

Kuali Baba SG

Bear in mind that petrol vapour is also lost through the filler cap, even when it is closed.

popikachu SG

Get a bicycle lor... Mr. Green

kikenfire88 SG

no matter full tank of half tank, they also deplete with time, vapourise fuel will either leave the tank or condenses and return into droplet form on the wall of the interior tank.

2nd may be right to say that less weight means less torque need to start off, but that means that lesser pressure to force ur wheels to the ground, meaning lesser grip and stability decreases.

just my $0.02

[email protected] SG

lighter will also help fc. that's why unload any unnecessary stuff from your car. e.g. golf set, books, car shampoo, ...etc (used maybe once in a month but carry with u all time)

look at F1 race as example.

1. driver run with full tank, less pit stop (save time) but slower top speed cause heavy

2. driver run with half tank, more pit stop (waste time) but higher top speed

all this brilliant F1 team calculate every possibilities or so call strategy to win the race. the driver may run with full tank if their team take longer time for pit stop.

my $0.01

veron soh SG

Nope,modern cars are equip with 'Charcoal filters',the vapours will go there,& turn it back to petrol,then goes to the engine.

AndrewPKYap SG

I think hor, because the tank is air tight, the vapor loss argument is flawed…

AndrewPKYap SG

not that I am saying the other guy is right either… because the time you waste having to keep topping up must be taken into consideration…

Kuali Baba SG

Those cars are more sensitive to weight changes. An F1 car has to have a minimum weight of 605kg (with driver on board) and can take up to 130 litres of fuel. (It's not just about top speed but also reduced inertia under braking and higher cornering speeds)

Your average family saloon weighs around 1200kg and carries up to half as much fuel as that. The effect on the latter will be less pronounced though the principles do apply.

Thanks for the correction about the filler caps, Veron.