Have you ever run out of gas? The gauge on your dashboard is perilously close to the red, with the needle almost pointing to "Empty." Stranded, what do you do? Should you call for assistance, trudge to the nearest gas station or wait for some kind-hearted soul to pull over and help?
The answer could now be close at hand: researchers from Ohio University in the US are not taking the proverbial but claim that urine could power the cars of the future.
According to the UK's Royal Society of Chemistry, Gerardine Botte - an associate professor at the university - has been working on a new technique that uses the unlimited natural resource to produce hydrogen, and all with a fraction of the energy needed to extract it from water.
For some time hydrogen has been heralded as a more environmentally friendly way to power vehicles and an alternative to conventional fossil fuels, particularly because the only emission generated is water. However, its development has so far been limited by hefty production costs.
Electrolysis, Botte says, can be used to break down urine's main component urea to release hydrogen.
Botte has been working on the development of a nickel-based electrode to oxidize the urea using a voltage of only 0.37V rather than the 1.23V needed to split water.
Research was initially carried out using synthetic urine made from dissolved urea, but it turns out that human urine is just as effective - and far easier to source. However, Botte admits that it was an extremely lengthy process to get approval to test it.
If this proves successful, future applications could see this method adapted for use in wastewater treatment facilities.
So not only will your gas tank never run dry again, but you will no longer be hit in your wallet by wildly fluctuating prices.
Whether the oil companies will be enamored by this new development remains to be seen.
Who knows, perhaps drinking - water, of course - and driving may actually be necessary in the future? You just have to be careful where you choose to fill your fuel tank.