Filling the car up.........

discodiva123

When i get paid i always put £30 in so the tanks full, i like to make as few trips to the petrol station as possible, this months thats lasted me til today and ive put a tenner in.

cowbutt

steve700 wrote: »

It's the same principle as driving around with a boot full of stuff that you don't need. The heavier the car, the more fuel it must use to get around.

Not that I know what 45 litres of V-Power fuel weighs................

According to http://www.csgnetwork.com/specificgravliqtable.html the specific gravity of vehicle petrol is 737.22, so 45 litres would be 33174.9 grams, or about 33Kg - about half the mass of an adult passenger (who's on a strict diet and is therefore losing mass every journey!). Given that the mass of a car is usually 1000-2000Kg, 33Kg is pretty much neither here nor there, and will have very little effect on fuel consumption. If you're that concerned, start pulling out your stereo, junk in the trunk, wheel trims, and so on.

snails's_pace

cowbutt wrote: »

According to http://www.csgnetwork.com/specificgravliqtable.html the specific gravity of vehicle petrol is 737.22, so 45 litres would be 33174.9 grams, or about 33Kg - about half the mass of an adult passenger (who's on a strict diet and is therefore losing mass every journey!). Given that the mass of a car is usually 1000-2000Kg, 33Kg is pretty much neither here nor there, and will have very little effect on fuel consumption. If you're that concerned, start pulling out your stereo, junk in the trunk, wheel trims, and so on.

.......... and what are you left with?...a freddy flinstone mobile :D willmmmaaaa!!!

CharliesAngel

buxtonrabbitgreen wrote: »

I fill mine up when I get paid. But OH only puts a bit in at a time. his theory is that if the car gets nicked at least they won't get his petrol too.

Hehe I'm a believer in that theory too....

DKLS

Fill up once a month, I wish, more like a fill up every week. Usually its £35-50 a week.

sinizterguy

Fill it up.

Have seen the calculations on additional fuel used to carry around the tank and it is negligible. Its like throwing a small bag into your car or something.

And you would waste more petrol going back and forth to the petrol station that you would save by not filling it up.

Of course that doesnt apply if you live opposite a petrol station. Or if you pass one on your daily commute and youre disciplined enough to check everyday and top up before you need to have a panic run to the pumps.

Idiophreak

Gemmzie wrote: »

When the thingy clicks it's full, anything past that and you are just wasting money because the tank is full and those extra drops of petrol just run of somewhere. (Cousin's a mechanic)

I'm no mechanic, but I'd be *very* concerned if that were the case.

AFAIK the "click" comes when a certain pressure is reached - this is triggered by a small nozzle within the handle starting sucking petrol, rather than air (ie once it comes into contact with the rising fuel). BUT - once the click comes, the fuel continues to drain into the tank, fill up voids, air filters out etc - thus allowing you to fit more in.

By way of a less scientific explanation...today I filled my car up, the first click at "maximum speed" came around £40.05 iirc...I then squeezed more gently for a minute and got it up to £41.20 or something, then it clicked again. Squeezed it more gently still...£41.70 more gently..more gently...until, eventually, I hit £42.42 - the magic number.

(shows up on the credit card bill well )

The suggestion that 2.5l of fuel has just "sorta wandered off" is pretty weird and not (given it's flamability etc) overly likely imo.

As to when to fill up...it's quite well advised that you don't run your car empty as much as possible - deposits build up in the bottom of your fuel tank over time (dodgy additives from cheap fuel etc) and it's best to leave them there, rather than suck them through your engine. That said, I tend to leave it til the light comes on most times just because I don't think about filling up, basically.

I do worry about "lugging all that extra fuel about" - but my car drives a lot better on a fuel tank (engine likes a drink - and sitting a little lower helps the ride...) so I don't worry too much. And as others have said, I think it's a pretty small difference in the scheme of things.

rayday2

The reason there is a click to tell you it is full is because fuel expands when warm so there needs to be expansion room if you go past that well its not advisable your imagination can work it out! So there is more room past the click and it does not leak anywhere!

smudgemanc26

Well i fill mine up when i get paid so i dont spend the money but it doesnt last until next payday so i end up going and putting £10 here and there in. Today though im driving around with my petrol light on which i know is bad but have no money till tomorrow.

A couple of things i have learnt from this thread is that the petrol pumps click when your car is full (didnt no that i always get scared and just guess at the amount of money i spend whether the tank will be full or not!)

And dont give lifts to fat people cos this will use more of my petrol up! :rotfl: And i cant afford to be doing that now!

toontastic

tsharp wrote: »

You will waste fuel if:
You have the A/C on all the time

However myth busters proved you use more fuel if you have your window down than your A/C on so if your hot use your A/C if you have it not the windows.