By Malcolm Brabant
BBC News, Greece-Albania border
The campaigners explain how the cooking fuel works
Chip fat-powered rally driver Andy Pag was cock-a-hoop as he steered his sticker-covered car into the forecourt of a sleepy Greek taverna just over the border from Albania.
"Today we have successfully completed our mission," he declared, punching the air with delight.
"We have arrived in Greece, powered by nothing but grease!"
Nine days after leaving a "greasy spoon" cafe in North London, he and his team of adventurers had achieved their ambition to traverse Europe without using fossil fuels.
Instead of filling up at petrol stations, they have been pulling into restaurants and charming often bemused chefs and owners into donating their waste cooking oil.
There were some casualties on the way. Two drivers fell for the charms of some Croatian girls and decided to remain on the Dalmatian coast.
And another man dropped out when his wife ordered him to attend a family wedding or face a divorce.
"We have shown that it can be done," said Esther Obiri-Darko, a London chemistry teacher, and Andy Pag's partner.
"The Germans had fantastic oil. I think they change it every day."
But in some places they struggled to get supplies.
"Some people just didn't get it," said Esther. "But most people wanted to help the environment and were happy to help."
Cocktail of oils
On arrival in Kalpaki in Greece, the team found a warm reception and obtained a donation from taverna owner Theodora Eleftheria.
Mrs Eleftheria led them to a covered plastic barrel containing a toxic-looking cocktail of waste vegetable oil from frying potatoes, and olive oil used for traditional Greek dishes.
Andy and Esther rubbed the oil through their fingers, sniffed it, and declared it to be perfect for their purposes.
The car has been specially modified to run on waste fat
Esther cut a square of muslin and they filtered the oil into a plastic tank.
A gaggle of Greeks gathered around the bonnet of Andy's ancient red Peugeot.
It has been converted to run on vegetable oil. Others on the expedition were using bio-diesel made from converted waste chip fat.
Andy lifted up the bonnet, and showed them a centrifuge used for purifying the grease.
"The oil gets very hot and so it gets very thin. And then it goes into the centrifuge where it spins around and because it is very thin, it separates all the water and all the food remains. And all the clean oil comes out the bottom."
Mrs Eleftheria had summoned her brother-in-law - a mechanic - and it was clear that he would soon have a major engine conversion job on his hands.
"I want my big cars to run on this system," said Mrs Eleftheria.
"I think it is very nice for our children. The Earth is telling us to do something. I think it is the best thing to do."
The statistics of Andy's odyssey are impressive.
He has travelled more than 2,000 miles (3,200km), using about 45 gallons (200 litres) of chip fat. His car has been doing more than 40 miles to the gallon, which he claims is better than normal diesel. And he has also saved more than 350 euros (£300) in petrol station bills.
Andy Pag (l) said international cooking habits might hamper the journey
"Hopefully, it will give people a bit of confidence to try alternative fuels, maybe using bio-diesel or converting their cars to vegetable oil," he says.
"When I first did it I was really nervous that I was going to wreck my car. But I am now confident that it is a really viable alternative. As far as my driving life is concerned, I really can't see why I would want to buy any fossil fuel ever again."
And with that Andy and Esther jumped into their car, overloaded with jerry cans of scavenged chip fat and a giant tent.
They were heading to a campsite in Ioannina where they were going to set up the centrifuge and purify the day's pickings.
Then they were planning a leisurely cruise down Greece's western coast towards Athens and a celebratory reception at the British Embassy.
But this is not the end of the road.
Next year Andy plans to circumnavigate the globe with a mixture of cars, boats and planes.
And the aircraft, he says, will be powered by aviation fuel made from plastic bags.
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