Fill petrol only to click, or all the way?

sd8974

Hi,

My mum says she heard it was more efficient to only fill your car up to the click on the petrol pump, rather than filling it up all the way...is there any evidence that this would make any difference?

Shane.

anewman

My car manual says to do it only till the first click. I have followed that advice since the last time I tried filling up more it all shot back out of the car and dripped down.

I'm sure I have read somewhere that if you fill more than the first click, some of the petrol you end up paying for ends up going into some sort of overflow.

I also tend to up end the pump nozzle and lift the pipe to try get the last bit left in the pipe

Stephen_Leak

Erm, isn't "the click" and "full up" the same thing?

sd8974

anewman - Does your car manual say why you should only do it to the first click? Do you reckon this overflow wouldn't just feed back into the tank?

Stephen - Nope. Usually you can get 2 or 3 clicks and then still put more petrol in. I usually take the nozzle out a bit so I can see it going in, so's to avoid the type of accident that anewman mentioned and to get the last out of the pipe!

ariba10

sd8974 wrote: »

anewman - and to get the last out of the pipe!

There is no way you can get the last out of the pipe without cutting it.

anewman

sd8974 wrote: »

anewman - Does your car manual say why you should only do it to the first click? Do you reckon this overflow wouldn't just feed back into the tank?

Doesn't give a reason but my guess is it just says for some safety reason. Perhaps it was just the pump I was using at the time which made it happen.

It says here

http://www.consumer.org.nz/topic.asp?docid=1293&category=Cars&subcategory=Fuels&topic=Economy%20driving&bhcp=1

Fill the tank to the first automatic cut-off click. Overflow wastes your dollars.

sd8974

Ah, I think I understand what it means by overflow now...I think it's more the kind of overflow that spills out of the car and onto your shoes that it's warning about, rather than a type of overflow inside the car where the petrol is lost.

It would be interesting to notice next time I fill up, just how much more petrol you can put in after the first automatic click - have you ever noticed yourself?

Crabman

If you look at the petrol nozzle, you'll see that alongside the large nozzle where the fuel comes out, is a small opening - that is a suction which senses when the fuel is reaching full.

When fuel is sucked up by the little hole instead of air, it clicks. That's why if you click more and more, you're losing more fuel (admittedly not much!) to the little sucker pipe.

balsingh

I know a lot of people who fill to the 'brim'. ie. they can see the petrol at the top of the filler pipe.

Not a good idea because on a hot day, the fuel expands and ends up leaking out through the overflow.

Alias_Omega

sd8974 wrote: »

Hi,

My mum says she heard it was more efficient to only fill your car up to the click on the petrol pump, rather than filling it up all the way...is there any evidence that this would make any difference?

Shane.

It would be more efficient to only fill the car up with what fuel you need.

With the car full of fuel, it weights more. About 1ltr of fuel is about 0.8kgs. Therefore its alot of extra weight.

You think about the car has to get that weight up to speed, and maintain it. Therefore you would find it uses more fuel, but not alot that you would notice.

Maybe 0.1mile per ltr or something..

manda1205

I agree with above, I only put about £10/£15 (half a tank)a week in mine and sometimes I dont use that. I've also been told it's good to let it run empty every month or so, so as not to create too much crap in the bottom of tank. I know a lot of people who just top their tanks up every week regardless and its not really economical. Correct me if I'm wrong though.