Essence sans plomb

I bought petrol yesterday because the petrol gauge in the car suggested that the car was going to be very hungry if I didn't. I noticed that petrol is a lot more expensive when I pay for it out of my own bank account rather than when I use someone else's credit card. I prefer it when someone else pays for my petrol*. Thankfully it's a small car with a small engine, so its fuel consumption is relatively low.


* This is usually the case because I just occasionally borrow a car rather than have sole use of one, but I have sole use of one at the moment because the usual driver has temporarily acquired another vehicle, but the downside of having permanent vehicular use is that I have to pay for it.