I remember petrol being around 50p a gallon as a lad (70s), then when I passed my test (1987), it was roughly £1.59/gallon.
My car is a Megane diesel, 1.5DCi. It runs on fumes on a run as long as I'm sensible with the speed and will easily return 60mpg. I don't really notice the cost of the fuel with it being so economical. Even around the doors, town and school runs, it's still returning low 50s mpg. It also has a 6th gear, it little more than ticks over at 55mph or so. I did notice the price of the fuel when I passed the station last week though and I thought, 'blimey, that's gone up.'
I did consider at one point a few years ago trying to run a Peugeot 307 on vegetable oil. When I looked into it though, it wasn't much cheaper as vegetable oil retails at roughly the same, often a little more than diesel and you still have to pay pollution duty on it too if memory serves me right.
I knew somebody in the village that used to use old chip fat etc from the local take aways and restaurants nearby. He used to 'clean' it with filters to remove solids and other things that filters on the car itself wouldn't like. I think there was a heating process used too to burn off other nasties before use. He was getting the oil for more or less pennies but he had to pay duty on what he used but it was still cheaper than pump bought diesel. He was paying roughly about a 3rd to fuel his car this way but he would also run some pump diesel too.
At the moment though, I don't really mind, my car returns the said 60mpg and our other car, low 50s, so it's cheap anyway, relatively speaking.
The knock on effects are what we are noticing more though, inflation and also the cost of delivering goods to the shops has gone up, which hits our pockets harder than us actually buying fuel for our cars.
