Paul Patrzalek’s house in La Mesa is impossible to miss: Outside in the front yard sits a 10,000-pound truck with a camper shell that looks — and sounds — not unlike a tank. It’s beige in color, adorned with the Mercedes logo. The cab is bright white, and the whole thing sits a good few feet off the ground. It looks utterly out of place in this quiet neighborhood, a hulking machine set down amidst the sedans and minivans.

This monster is a Unimog, a 1975 Mercedes behemoth that sits in Patrzalek’s driveway, dwarfing the surf-style ’60s wagon beside it and his one-story, peachy-white house.

In the Unimog sits Patrzalek, who has climbed aboard to start it. The vehicle rumbles to life, shaking with the effort, sound filling the street. Patrzalek revs the engine and the ground trembles. A grin stretches across his bearded face, eyes shielded by sunglasses and a military-style black cap. He says something inaudible, motor growling, words swallowed. He tries again, shouting over the din.

“Soon this will run on vegetable oil!”

That, he says, is the plan; when he gets the special conversion kit he needs, Patrzalek will make the necessary modifications to the Unimog that will allow it to run on what is known as “waste vegetable oil” or “straight vegetable oil,” which he collects from restaurants around the city. It’s called “greasel” in the grease-car community, not to be confused with “biodiesel,” which is veggie oil that has been chemically modified.

Over the past year, Patrzalek’s pet project of turning diesel vehicles into what have been termed “veggie cars” has evolved into a business — albeit a slow one. While most of the conversions have been done on-site at his clients’ homes, some he does in a larger workspace in Lakeside and in his La Mesa garage, which is crammed full of bikes, bike parts, car parts, and surfboards. Music blasts from a stereo hanging above Patrzalek’s workstation, a wooden table at the back of the garage covered in tools and debris.

The idea for converting cars first came to Patrzalek five years ago, but he didn’t get going on it until last year, after having seen Al Gore’s An Inconvenient Truth.

“I was watching [it] with a friend of mine, and I looked over and I said, ‘I’m out. I give myself a month to do the research, find a veggie car kit, or I’m going to quit driving altogether,’” he says, sitting at his desk at Adams Avenue Bicycles, where he also works as, in his words, a “parts guy.”

“With that kind of incentive,” he says, “[it] got me really quick to figure something out.”

After purchasing his conversion kit from Lovecraft.com, at that time the only online kit vendor that sold the one-fuel-tank system he was after, Patrzalek got himself an ancient Benz and began the installation process. The story is, as Patrzalek tells it, half determination and half kismet.

“It’s really funny, my buddy has a used bicycle shop and he just gets weird stuff,” he explains. “And out of the blue, I just call him up and I say, ‘Hey, Dave, do you have an old Mercedes you want to sell?’ And he says, ‘Yeah, I do.’ And the thing is so beat up when I got it that I barely got it home. I said, ‘Oh my God, what have I done?’ But then I finally got the kit from Lovecraft and threw it in, and I was just totally stoked.”

Another local grease-car driver is Joe Connor, a San Diego sportswriter who launched the Green Power Sports Tour, a tour of ballparks around the U.S. that he conducted in “the Green Machine,” a bright green Mercedes sedan that runs on straight vegetable oil. The tour, sponsored by several major companies including Autotrader.com and MapQuest, was completed in December 2007. Connor plans to embark on another beginning this August.

His decision to convert to vegetable oil was not financial, he says, but ideological.

“If America prides itself on innovation, I didn’t see any innovation in our energy policy,” Connor, who is currently in Central America, writes via email. “Therefore, I felt it important to make a statement.

“If I can do it, you can do it,” he continues.

That seems to be the prevailing theory behind grease cars: doing it yourself. According to Patrzalek, who has worked on vintage cars since his childhood, the kit works right out of the box. Both he and Connor haven’t looked back.

“The conversion is basically just hillbilly engineering at its finest,” Patrzalek says, popping the hood on a candy-apple red Mercedes wagon.

He explains the conversion process, which can only be made to diesel-powered vehicles. It appears technically daunting but, Patrzalek claims, can be done by anybody who is “a bit mechanically inclined.” The first step, he says, is to install a heated filter for the oil. The second is to take out the stock fuel filter and put in a heat transfer unit, a duel chamber that runs both fuel and coolant into the engine. Then, as Patrzalek explains, a special fuel pump must go in and hook into the coolant line so that the heated oil and the coolant can both travel to the motor. After hooking up all the necessary hoses, the job should be finished.

While many websites and other sources claim that in order to heat the oil, veggie cars must be started and stopped on diesel or biodiesel — a vegetable-oil-based fuel that includes several harmful chemicals — Patrzalek says he hasn’t had any problems.

“There’s always people telling me, ‘Oh, you have to start it and stop it on diesel’ and all that. And in our climate it’s not necessary,” he says. “For almost anywhere you don’t need to. You just need to mix kerosene or some kind of thinner with your oil to get it started in subzero weather.”

Melanie Zauscher, a third-year mechanical-engineering graduate student and founder of University of San Diego’s Biofuel Action and Awareness Network, says this depends on the system of the car, the oil used, and the weather.

“During the really cold nights, below 35 degrees, I’m even nervous [using biodiesel in my car] about [getting] stuck somewhere, because the biodiesel has jellified,” she says. “However, in San Diego I don’t really have to worry about that most of the year. You run the same risk with the vegetable oil, except it would solidify at an even higher temperature. That’s why people who use straight vegetable oil usually add heaters to their car to keep the oil less viscous than it is at room temperature. So it really depends.”

The Biofuel Action and Awareness Network is an on-campus group devoted to both educating the community about alternative fuels and implementing their use on campus, starting with university transportation vehicles. The network is currently working on a reactor that will allow them to make batches of biodiesel themselves.

Back in La Mesa, Paul turns on another of his veggie vehicles, a cherry-red Mercedes. Though not nearly as loud as the Unimog, it’s still a noisy car, engine jolting as it roars to life. A jet of smoke explodes from the exhaust pipe. It smells like a deep fryer.

“There’s Thai oil in there,” Patrzalek explains, smiling proudly.

Patrzalek’s business, named Greasel My Diesel, evolved shortly after he went veggie, when friends and friends of friends began to approach him about doing conversions of their cars. So far, he estimates he’s done 10–15 conversions. His clients, he says, are mostly environmentally minded people who want to go the extra mile to help minimize the effects of fuel emissions.

“They’re either going to be…very environmentally aware, into mountain biking or cycling, surfing,” Patrzalek says of his clients. “[They’re] just environmentally conscious people. [People] that would probably be eating organic food, aware of the environment. It’s usually not a cost thing. I mean, granted, it’s enticing, but mainly it’s people who are just concerned about the environment.”

With a vegetable oil car, fuel cost is not an issue; the harvesting of oil, however, is. Restaurants are the prime sources of waste vegetable oil and must pay to have it removed from their facilities. Many, according to Patrzalek, are happy to give it up and hand it off to him in the same five-gallon jugs they purchased it in. He can harvest, he says, 5–15 gallons per restaurant; two or three restaurants are enough to fuel his fleet of three — soon to be four — veggie oil vehicles.

Connor gets his oil primarily from Asian restaurants.

“Local places support it,” he writes. “The big nationwide chains couldn’t care less. Chili’s, however, has been great to me.”

“I enjoy it,” says Patrzalek, speaking of harvesting oil. “I enjoy picking it up. I go hunt it down. I enjoy the whole thing of it.”

Others, however, may not. The process is, as Patrzalek describes it, “gross,” not to mention laborious. First, one must locate oil sources and figure out how and when to pick it up. Also, before the oil can be used, it must be filtered to ensure it is free of food debris and other contaminants. For this process, Patrzalek uses a large plastic drum with a special kind of nylon filter attached to it that catches whatever gunk should not be in his fuel. This “home-fueling station” is kept in a shed in Patrzalek ‘s backyard, along with extra steel cans of filtered oil.

Every new oil source Patrzalek finds, he screens.

“If I find a resource and they agree to let me have it, I’ll take home a gallon, and I’ll watch it and I’ll see if water settles on it, how much fat is in it, or anything like that,” he says. “I’ve been at places where I actually won’t use the oil, it’s too dirty or it’s got too much fat [or] too much water in it.” Patrzalek says he disposes of the unacceptable grease in the restaurant’s grease traps, though having gotten his filtration and harvesting system down to a science, this happens less often than it used to.

But there are other drawbacks, which Connor outlines.

“Grease is like glue,” he writes. “It sticks to everything. [Also] grease smells [and] you have to keep things clean. You [also] can’t drive up to your local Shell station and buy grease; it takes time to find a source and then time to ensure you have good, filtrated grease.”

Difficult or not, grease car drivers persist and, for the moment, restaurant vegetable oil is relatively plentiful. There are, however, others out there that have found a use for the same product. Biofuel companies like San Diego upstart New Leaf Biodiesel, a corporation that is currently working on producing biodiesel for wholesale purposes, are installing locked boxes on restaurant premises for oil collection. New Leaf’s website boasts a laundry list of restaurants that have provided them with oil, well over 100 in all.

“Basically, we want to help clean up San Diego’s air quality by providing biodiesel and recycling a local product into local fuel,” says David Richards, co-founder of New Leaf. “We want to help transform the way fleets are using fuel by providing them with a cleaner alternative energy such as biodiesel.”

New Leaf is constructing its facility in Barrio Logan and plans to officially open in late April or early May.

Patrzalek, who still has his stock of oil sources, has mixed feelings on the subject.

“I mean, it’s great that they want to collect it and filter it and sell it, but I think there’s also a point where I kind of like the idea of still getting it for free,” he says. “I think it should totally be accessible. If people are willing to go through all the trouble of collecting it themselves and using it, I think it’s fantastic. I mean, I understand capitalism and whatnot, but it’s kind of rad that you can do that. If there’s no free vegetable oil available, that would totally suck.”

“I think it’s great,” says Richards enthusiastically, speaking of grease car drivers. “I think that what they’re doing is awesome. They have the same intentions as [we do], using alternative renewable fuels, and I don’t think there’s anything wrong with it. I think it’s great that they’re running an alternative or renewable fuel in their vehicles.”

Richards does, however, recognize the oil New Leaf is collecting as a commodity that veggie car drivers and collection companies use as well.

“Obviously, there’s a limited amount of oil in San Diego, and it’s hard to say how many people are out there using vegetable oil in their cars,” he says. “So it’s hard for me to answer that question [of] if there’s going to be a competition between us and them or what. Most of our competition is with existing businesses.”

While New Leaf seeks to provide biodiesel, Patrzalek and his fellow greasel drivers use only vegetable oil, not biodiesel. Biodiesel, while made from waste vegetable oil, is an entirely different form of alternative fuel.

Waste oil, Zauscher and her colleague Justin Klein explain, is too thick to run through a regular diesel engine. Biodiesel, on the other hand, is waste oil that has been chemically treated to remove glycerol — a sugar alcohol that acts as a thickening agent — and is thin enough to be used in unmodified diesel cars.

“When you convert to biodiesel, the thickness of it decreases, so you can run it in a regular diesel engine without modifications,” says Klein. “If you’re just running regular vegetable oil, you have to make modifications to heat it up before it can go into the engine.”

“That’s kind of why biodiesel is better because you don’t have to convert your car,” says Zauscher, who runs her Volkswagen Jetta on biodiesel. “[But] there’s obviously benefits to converting your car, because you can just get the waste vegetable oil from restaurants and not have to make biodiesel…”

The Biofuel Action and Awareness Network decided to promote the use of biodiesel on campus as opposed to other fuels for several reasons, which Zauscher outlines.

“The university would never use vegetable oil in their fleet, but we are called Biofuel Awareness and Action Network because we do want to encourage all biofuels, including waste vegetable oil,” she says. “It seemed more logical that people would be less scared of [using] biodiesel as opposed to waste vegetable oil, because biodiesel is more similar to diesel than waste vegetable oil is, and biodiesel doesn’t require modifications to the vehicle.”

Another advantage of biodiesel over vegetable oil is a legal one. While veggie oil conversion kits are sold all over the United States, the process is still illegal and has not been approved (or disapproved) by the Environmental Protection Agency. A spokesman for the agency told Mary Pickels of the Pittsburgh Tribune-Review that vegetable oil is “flammable under certain conditions” and points out the existence of laws “against tampering with vehicles that alter their emissions.” In addition, the conversion will definitely void any warranties a vehicle might have, though it is not an issue with the older-model Mercedes popular with veggie car drivers — their warranties have likely expired years ago. With biodiesel, few to no modifications are required, a definite advantage over vegetable oil.

Though not as cost-effective as vegetable oil or as simple to harvest, it is possible to make biodiesel oneself. However, while it requires only a few ingredients, the process is laborious and demands a considerable amount of know-how. It requires the use of several harmful chemicals, including sodium hydroxide (lye) and methanol, a petroleum-based alcohol, both of which demand safety precautions. Both Zauscher and Klein, along with other members of their group, are currently testing their homemade biodiesel in small amounts.

Some, however, are skeptical about the impact biodiesel will have. According to the National Biodiesel Board, biodiesel produces approximately 50 percent fewer smog-causing emissions than regular diesel, but some have found problems associated with its use. David Pimentel, a professor at Cornell University in New York, is one of biodiesel’s biggest critics.

“Including all the inputs, [producing] biodiesel using soybeans…takes 53 percent more fossil energy to produce a gallon of biodiesel than the production of a gallon of diesel,” he writes via email from New York. “Thus, biodiesel is a major contributor to global warming. We use soybeans for biodiesel production because it is the best, because we do not have to use nitrogen fertilizer with soybean production. Nitrogen fertilizer for rapeseed or canola production requires about 33 percent more fossil energy.”

Connor, on the other hand, doesn’t agree with those who are suspicious of biodiesel and other alternative fuels.

“In my view, we need to explore, and not shoot down, multiple energy options, from biodiesel to vegetable oil to ethanol to hydrogen cars and on and on,” he writes. “When you have choices and competition, prices go down. When you have exorbitant demand and limited choices, you have what we have now and will continue to have: high prices.”

“I’ve never felt comfortable buying gas,” says Patrzalek. “I’ve spent the past 15 years commuting to work by bike, so I’ve been fortunate enough to not have to really rely on internal combustion, because I feel like a sucker buying gas.”

For him and for Connor, vegetable oil was the logical choice.

Still, veggie car drivers have a lot to face, skepticism perhaps being the largest obstacle in their path.

“I’ve been at Henry’s and had one of the clerks give me crap for not bringing in my own bags, and I just said, ‘I have a veggie car outside,’ and they said, ‘No, you don’t. You can’t do that,’ ” Patrzalek says. “And I backed up my car almost to the door, and you can smell it when it’s burning, and they still didn’t believe me.”

He pauses.

“The funny thing is I got so many people calling and asking questions about it, going on and on, but still, I wasn’t able to sell a car,” he continues. “I don’t know. They’re just not ready for change. They’re so conditioned to go to the fuel pump for it, and when you have something new like this, they maybe don’t feel comfortable about it or they don’t believe it. It sounds too good to be true.”

According to Patrzalek, it’s not.

“It just takes a bit of tenacity,” he says, “that’s it.”

— Rosa Jurjevics