Battery powered conversions. I'm getting warmer.

[Craig T]

I used to run Range Rovers on LPG. It was very good at the time but all the stations I used to fill up at have now removed the LPG tanks?

Hydrogen is a difficult one as it's not very good as a gas pumped straight into the engine like LPG is. Hydrogen is very slow burning really so an engine will run on it but very poorly. Look at the film of the Hindenburg and see how slow that burnt. If that had of been filled with petrol vapour bits of it would have been 50 miles away from where the fire started.

Running an engine on oxygen and acetylene gas mix would be exciting until the pistons melted....

Craig.

[Wittsend]

... It doesn't really matter

The sun is the same in a relative way but you're older
Shorter of breath and one day closer to death

[Theshed]

How old is my hand-me-down iPhone 5?

My phone Nokia, or Samsung can't recall, is now 5 years old and works fine for me. I did embarrass my son by throwing it onto the floor in the Apple store when returning his 6 month old and broken I-phone. Just to prove a point you understand. 

[jonhutchings]

Though I have a company supplied iPhone, my own phone for personal use is a Caterpillar B30 e.g https://www.amazon.co.uk/Dual-SIM-Display-1000mAh-Battery-Waterproof-Black/dp/B00X6BSR00

I bought mine in 2017 brand new for £40, I still only have to charge it once a week. The best bit is it makes the sound of a CAT diesel starting up when you turn it on and off, and the only alert sound you can have is the horn from a cat bulldozer