Filled my car up this morning, and was wondering, as 52 litres entered the tank, does having a full tank vs filling up half way make much difference to fuel economy?.

I know its a bit anal, but there you go!!, do you "fill up"?, or just put a bit in here and there?

I always fill up to the top, the way I see it I'm going to use it either way and this just saves me more trips to the petrol station

I drive literally past the door of the filling station everyday, so filling up more offen wouldn't require a special trip.

The only reason I fill up, is pretty much because I can't be arsed to fill up more than I have to!!

I fill up the Daily hack all the time, and the weekend toys only get £20 or so at a time as they only come out for a few hours each weekend. No point in filling them up.

If you fill up every time, you know the amount of fuel used so working out accurate MPG is possible.

I do it because it means less trips to the pump though.

Usually I refuel with either 20 or 40 euros, depending on how much I have to drive during the week.

And just to note, I try to never let the fuel gauge drop below half.

Quote from Matrixi :

And just to note, I try to never let the fuel gauge drop below half.

Why is that?

Logically I would say that a 60L full tank is like the weight of a passenger (woman ) and an heavier car means higher consumption....that said I am lazy and always tank full...

Quote from Framaris :

Logically I would say that a 60L full tank is like the weight of a passenger (woman ) and an heavier car means higher consumption....that said I am lazy and always tank full...

Well, yeah, exactly, but just HOW much more consumption is the question.

I always fill up (~25 litres), but my capacity is only 30 including reserve. I do from 400 to 500 km on that, depending on weather and type of driving. If I only do grocery runs, I get like 300 Funny thing is, I get worse mileage running VPower or Ultimate.

Quote from danowat :

Well, yeah, exactly, but just HOW much more consumption is the question.

Depend on the car, try to tank full and write down how many kms you did with it, then tank 3 times 20L and addition the kms you did with it, should give you the difference....

Thats the thing though, its hard to get accurate consumption figures when you don't brim the tank.

I normally run at 1/4 tank or under. Makes me save fuel more and makes me think i have to make the fuel last as when i have a full tank, i dont worry about it and dont care how much throttle is used.

it's not really a lot what you'll save.
But, if you want to save money, just fill it half.
I mean, it'll only save you a couple of quid in a year.
And when tanking twice as much, it is possible that you sometimes have to tank for a higher price.

So no influence on your wallet, little influence on the environment.

They did something like this on mythbusters.
They tested if it saved fuel if you drove with the pick up lid open or closed.
Which makes me wonder, why would you care if you drive a pick up?
Closed was better for the consumption though.

Yeah, I saw that mythbusters, its along the same line as, driving with the window/s open vs using the air-con.

Since I always tank full and I drive 25.000 to 30.000kms a year I use other means to save some fuel, like having my tires a bit harder dan normal to reduce the contact patch and I use michelin energy tires which makes me save about 10% fuel when driving normally...

I did think about those "energy" tyres next tyre change, do they actually make that much of a difference?

I normally fill it when it gets below 1/4. If your car has a in-tank pump then the fuel acts as a coolant, low fuel could cause it to overheat.

Quote from danowat :

Why is that?

Shrug, I like to keep enough fuel in my tank so if I like to take a bit longer shopping trip on seconds notice, I don't have to drop by at a gas station before that.

Sure the car will haul a bit of excess weight in the form of fuel, but atleast I'm not prone to running out even if I'd decide to take a trip to lapland for example, where gas stations are rare to come by.

Well I don't think it makes much of a difference is you drive only in cities, but for me who drives (cruise) long distances it does!

Ye you should always fill up the tank full

I fill it up as long as the budget allows me to do so. Don't care about the extra weight of 20 liters of petrol, there's already enough crap in the car I could take out (20 kilos of tools in the trunk). I don't care much for mileage though.

If it drops below 1/4 of a tank, I'll put £10 or £20 in. Depends how rich I am at the time.

Quote from BlakjeKaas :

Which makes me wonder, why would you care if you drive a pick up?

Interesting concept. If I have to haul stuff all the time and need a pickup truck, then I don't care whether I would get better fuel mileage or not. But if I don't have to haul stuff a lot and drive a car, then I would....

Ever think that not everyone wants to drive around in a little tin box that can't get up to speed just to worry about fuel mileage? I liked to go 4wheeling as recreation and also camping, which even some trucks wouldn't make it to my camping spot. Thus, I chose the truck based on my needs, which was to climb down the near vertical slope, cross the river, and climb up the near vertical slope. Because of that, I didn't care about the mileage I got in my truck?

I have to fill the wife's because she can only go 3 days to work on a full tank. Usually I have hardly anything left in the checkbook after that, so I fill mine up with about $10 worth. I can go all week on $10.

Quote from Bean0 :

If you fill up every time, you know the amount of fuel used so working out accurate MPG is possible.

I do it because it means less trips to the pump though.

My pov exactly!