zlacker

>>Techno+(OP)
When see things like this, I always think of the Chinese proverb

"An inch of time is worth an inch of gold, but it is hard to buy one inch of time with one inch of gold"

Which always says to me that its not worth it just use the quickest option

Take the example drcongo posted:

"Yesterday I had to drive to a nearby town, just 20 minutes away, and noticed that every single petrol station there was a good 5p per litre cheaper than my town. I might plug this into a map."

Assume he uses 30 litres a week (high end of average UK usage) that's £1.50 per week saving but assume the extra miles use half a litre, that takes about 65 p off the saving (ill not go into wear and tear) over 30 years of work 50 weeks a year this means a saving of £1,275 over 30 years ... sounds a lot but

20 mins away - this assumes 40 minutes per week over 50 weeks is 2000 minutes, and over 30 years 60000 minutes. Now assume you are awake for 16 hours a day this equates to 62.5 days of free time - more than two months of awake time

so as the saying goes... which would you prefer £1,275 saving or 62.5 days of time

>>maffyo+99
I've also wondered about whether to fully fill my tank or drive on a small amount so that I'm not using fuel to carry fuel. Do you know of any metrics on that?

>>oniony+U9
I haven't made any calculations, and it's more a hunch, but considering you usually need to remove hundreds of KG in order to make an impact on how much fuel is being spent, 40-50L of gas (~40KG difference between full and empty maybe?) would have an marginal effect on how much fuel is spent to carry a full tank vs 10% filled tank.

Besides, with a smaller tank, you'll make more trips to tank it, and also have less choice to go to gas stations that are further away but have cheaper price. Then again it becomes a question of "Do I want more time or more money?", back to square one :)

Edit: Also, someone correct me if I'm wrong, but doesn't the fuel pump use fuel itself as a coolant or something? Never investigated myself, but some car-knower once told me that running the tank on low always isn't good for the fuel pump, or something like that. If that's true, running with 10% of the fuel would mean more maintenance too, potentially removing any savings in the first place.