Bo and Kathleen Lundgaard haven't filled their 2000 Volkswagen Golf at a gas station since March.

Instead, the couple has been running the car on something a little less pricey: fryer oil.

The Lundgaards, who have owned Tony's Pizza for nearly 10 years, take used oil from their fryers and from other restaurants around the city and convert the dirty muck into liquid gold biodiesel.

"It's like a little treasure,” Kathleen said of the oil this week.

"(Restaurants are) like, ‘Here, just take it!' and it's like, you don't realize what you're throwing away, man!

"But then who has the inclination, the space and the know-how to actually get down and buy all the tanks and everything?”

Turning the "treasure” into fuel is quite a process.

Bo goes around town picking up 16-litre jugs of used oil up from about half a dozen local restaurants every week. He says that while the pickup is the hardest part of the conversion, the hard labour is worth it, not only for him, but for the restaurants as well.

"They're happy that we're picking it up. Otherwise, it just ends up in the dumpster,” said Bo.

The oil then has to be filtered and treated with methanol and lye, then washed and dried before it can be used.

And, because lye isn't available locally, the Lundgaards had to go to Edmonton to buy 150 pounds of the corrosive alkaline substance before they could even start.

They also had to purchase several tanks and a hot water heater for the set-up.

Bo, who learned how to treat the oil through research on the Internet, has taken over the garage to make the magic happen.

"It looks like a little mad scientist lab in there,” Kathleen said.

One batch of biodiesel takes about three days to make, but the hard work pays off; as each batch yields about 30 gallons.

Because the Golf has a diesel engine, they didn't need to make any modifications to the car, which they use not only for getting around town, but for delivering pizzas.

The price of gasoline – which jumped to between $1.38 and $1.41 per litre at local stations this week – was the Lundgaards' main impetuous for making the switch.

They used to spend about $90 for a tank of gas. Biodiesel costs them $17 a tank.

"If we were to make a road trip to Skagway and back, it would be about $8,” said Kathleen.

Their new energy source is environmentally friendly, too. Biodiesel is not only cleaner-burning than gas, but a renewable resource as well, since it's made with vegetable oil or animal fat.

"I tell people, ‘We've gone green!'” said Kathleen with a laugh.

The Lundgaards have also found a way to utilize biodiesel at home, by burning it in their furnace. The switch wasn't quite as smooth indoors, however.

"We thought we could just put it into the tank,” said Kathleen.

"The whole house just smoked up.... it was bad. Our house was just black smoke. It looked like there had been a fire in our house, but there wasn't.”

It turned out to be an easy fix, however. The Lundgaards replaced the furnace burner and by March, they were successfully burning biodiesel for heat, saving the family about $400 per tank fill.

There are some drawbacks to using the new fuel, however.

Biodiesel gels up when it gets cold, so while the Lundgaards can use the fuel in their furnace year round, it won't be a viable option for the car once the temperature starts to drop.

Right now, they are planning to use pure biodiesel as late in the year as possible, then switch to a 50/50 mixture of biodiesel and petrodiesel before going to straight diesel when things really get chilly.

Another difference between petrodiesel and biodiesel is the smell of the exhaust.

"It smells like dirty oil,” said Kathleen. "Not like French fries, like some people say. It just smells like used fryer oil.”

Overall, the Lundgaards are more than happy with the results. So much so, in fact, that they are planning to buy a diesel engine VW Jetta and run it on biodiesel as well.

And while the savings haven't quite paid for the start-up yet, Kathleen is looking forward to the day they do, likely by the end of next winter.

"I'm going to mark it on the calendar,” she said, laughing.