Many of us are tempted by the enticing wafts coming from the Costa coffee machine when we queue to pay for our petrol but the very by-product created by the caffeine-rich hot drink could, one day, also power your car.
Researchers at the University of Bath have revealed that 10kgs of leftover grounds produced by a typical bustling coffee shop on a daily basis could produce around two litres of biofuel.
The study, published in the journal Energy Fuels, found that different varieties of coffee - including Robusta and Arabica - have reasonably uniform composition and physical properties for use as a fuel.
Researchers say that oil can be extracted from the spent coffee grounds by soaking them in a special organic solvent before using a process to transform it into biodiesel.
Although the two litres produced by an average coffee shop's waste doesn't sound like much, researchers are keen to point out that is enough to power a small delivery van for around 20 miles.
But, should the process be scaled up nationally, popular high street shops such as Starbucks, Costa Coffee and Café Nero could be rivalling the major oil companies in just a few years.
"Around eight million tonnes of coffee are produced globally each year and ground waste coffee contains up to 20per cent oil per unit weight," Dr Chris Chuck, Research Fellow at the university, told the Daily Mail.
"This oil also has similar properties to current feedstocks used to make biofuels. But, while those are cultivated specifically to produce fuel, spent coffee grounds are waste."
PhD student Rhodri Jenkins, who was also involved in the study, told the Bath Chronicle: "We estimate that a small coffee shop would produce around 10kg of coffee waste per day, which could be used to produce around two litres of biofuel.
"There is also a large amount of waste produced by the coffee bean roasting industry, with defective beans being thrown away. If scaled up, we think coffee biodiesel has great potential as a sustainable fuel source."