Two competitors get their personal dose of grease ahead of the race
Much has been said about our throwaway society, and in north-west London 10 cars and their drivers are trying to prove that by recycling cooking oil people can save money and the environment at the same time.
Under the banner "Grease to Greece Rally", crews are preparing for their 2,500-mile (4,023km) journey to Athens.
As the cars take their places outside the Ace cafe, there is a familiar smell in the air. But where is the whiff of chip fat coming from?
I quickly realise it is very much generated from outside.
Standing in a haze of blue exhaust, looking very pleased with himself, is the man who has organised this smelly event.
Last year, Andy Pag, from Croydon, drove a lorry from the UK to Timbuktu in Mali powered with biodiesel made from waste chocolate.
This year he had to go one better. He says the aim is to see if it is possible to travel long distances without filling up at petrol stations.
"We are in the hands of Europe's kebab shops," he said.
Going into eating houses asking for dirty cooking oil is guaranteed to raise a few continental eyebrows but to ensure the language barrier does not stop the wheels from turning, Mr Pag's wife Esther has laminated phrase notes for each driver.
The only van in the rally is driven by Rob Taylor from Lancashire.
Pit stops will involve stocking up on waste cooking oil
That vehicle looks like it would have difficulty making it around London's ring road but he assures me his jalopy has never run better since he converted it back in February.
When asked if it smells when driving, he replied with a smile: "Only from the outside."
Mr Taylor's conversion kit cost £70. A quick look under the bonnet reveals two silver boxes the size of a large cigarette case.
He says a proper heat exchange would cost around £500 but at £70 his model has paid for itself many times over.
In Lancashire, Mr Taylor says his supply of waste cooking oil comes from residential homes and he rarely has to buy diesel.
But he is unsure if it is damaging the engine.
"She has already done 188,000 miles, if the engine goes I'll just replace it," he said.
But Mr Taylor is facing a bigger problem.
He has the ability to carry 600 litres (132 gallons) of waste cooking oil but as yet he has not bought a fuel filter to remove the bits of burnt sausage and kebab that inevitably find their way in the treacle mixture.
Mr Taylor punches his mobile in the hope of constructing something suitable along the way.
Fuel filters aside, Mr Taylor and his co-driver look like they have the ingenuity necessary to reach their destination and perhaps more importantly to get back.
The aim of the rally is to prove that grease as a fuel makes sense
Parked alongside him is a VW Touareg, which has one of the largest diesel engines you can buy but it runs on biodiesel.
You can put cooking fat in it too but it has to go through a filtration system first.
James Hygate bought the VW three years ago and has done 20,000 miles (32,186km).
He runs his own green fuel business, which started out as a hobby in 2003.
However, he says the credit crunch has seen commercial activity treble in the past six months.
"I think people are sceptical whether this oil can be converted into biodiesel but it is changing," he said.
"At the moment we're selling about 100 filtration units a month and the number of people using them is growing."
Mr Hygate goes on to say the cost of the fuelpod can be recouped in the first year.
The rallygoers say it all makes sound economic sense. And that is what this rally is all about, says organiser Andy Pag.
Standing in front of his red Peugeot 406, it is time for this adventure to begin.
As the bearded environmental campaigner heads off, he says what he wants more than anything is for us "to give grease a chance".