Fuel fill up to max?

[StuAff]

As the fuel tanks in my vehicles are 8L and 12L respectively, I stick to filling them up......

 

[Stephenite]

I fill to about 2/3 tank each time. This amount takes me to around a range of 600km. I don't drive so much these days so this lasts quite a while.

 

[Stephenite]

In my car the low fuel light comes on with 100km left in the tank. I ignore this completely unless I'm on a long trip. When the gauge shows 40km to go then I take interest. At this point I try to drive super efficiently, and will not be dictated to by the car manufacturers/oil producers, but to my partner and kids this is the start of a perilous adventure as we traverse nursery, school, jobs and shopping.

 

[Reynard]

I'll typically throw £20 when it gets to a quarter of a tank. If I'm going on a long journey or going to be using the car a lot in a short space of time, then I'll fill right up.

At current prices, £20 equates to about half a tank.

 

[Stephenite]

[QUOTE 5325130, member: 9609"]I do this too - I have calculated my (after light) distance is 80 mile at 55mpg, i once took it to 72 and managed to get 58.64 litres in. I get this strange urge that when I have very little fuel left I need to drive quicker to get to the filling station quicker - obviously I don't as you need to drive slower and more economically but something in my brain wants to get there quicker - strange.[/QUOTE]
I don't really know how close to empty/absolute zero I can get my Passat '06. As it's diesel I daren't risk it.

I had a brilliant petrol '98 model Golf a bit back. You knew it was about to be empty when it started coughing.

The past week I've been driving a rental - a new Audi A3. As I've only had it a short time I didn't read the instructions. I soon found out though. It's a hybrid and when you brake the drive moment/torque charges the drive battery. This introduces a whole new variable for the miserly motorist

 

[Jenkins]

I work out the cost of what I need for the trip(s), round it up to the next £5 split and put that in - doesn't take long to work out.

For example: weekend at Brands Hatch = 2 x 180 mile round trips = 360 miles. Working on 50MPG = 7.2 gallons = 33 litres (rounded up) @ £1..33/litre at current prices = £43.50(ish) so £45 of fuel into the tank. Usually leaves me with 1/4 of a tank as a minimum, but I hardly use the car other than for long trips during the summer. However, over the winter, I'll just stick £20 worth in as and when needed.

 

[slowmotion]

Never mind this fuel tank extra weight stuff, the real economy is to turn off your windscreen wipers when going under motorway bridges. You know it makes sense.

 

[marzjennings]

Fill to max each time and usually fill again each time I get to half a tank. Been caught twice with an almost empty tank when we need to evacuate town. Don't wish to get caught out again.

 

[Drago]

Is it pointless? Less fuel on board will for many mean more frequent journeys out of their way to visit the filling station, which equals more miles covered, more fuel used.

 

[vickster]

Fill to max each time and usually fill again each time I get to half a tank. Been caught twice with an almost empty tank when we need to evacuate town. Don't wish to get caught out again.

Is fuel still silly cheap in Texas. I recall paying a dollar a gallon or less about 25 years ago

 

[Joey Shabadoo]

Never mind this fuel tank extra weight stuff, the real economy is to turn off your windscreen wipers when going under motorway bridges. You know it makes sense.

On older cars you can stop the wipers vertically on the windscreen for better streamlining.

 

[nickyboy]

Take a large estate, such as a Mondeo. The last one I drove had a 62l tank. Diesel has a density of 0.83kg/l, so a full tank adds 62 x 0.83 = 51kg.
That's about 60% of a full grown person with a mass of 80kg. (Looks back fondly to the time when I was 80kg)
The mass of a 1.6 Zetec Mondeo estate is 1524kg. A full tank is 51/1524×100 = 3%, or as we say in the trade, two tenths of naff all.
You can't run a car with an empty tank, so the 51kg mentioned is very much a worst case.

Very fuel inefficient? I think not.

You're absolutely right. To take this even further, if you fill to the max and refill on fumes you're on average carrying 20.5kg of fuel. If you only fill to half full you're carrying 10.25kg

So the differential is a massive 10.25kg

Faffing around with twice as many journeys to the petrol station I bet uses up what you save on the weight

 

[Electric_Andy]

Fill to the brim, fill up again when low light comes on. I have to go out of my way to get fuel, so filling up more often is counter productive

 

[stephec]

You're absolutely right. To take this even further, if you fill to the max and refill on fumes you're on average carrying 20.5kg of fuel. If you only fill to half full you're carrying 10.25kg

So the differential is a massive 10.25kg

Faffing around with twice as many journeys to the petrol station I bet uses up what you save on the weight

Does that mean it's more economical to do one big weekly shop with ten bags of shopping, or three smaller ones and stick a tenner in the tank each time?

 

[GM]

I put just under £30 in so I can pay contactless, lasts about 2 weeks.