The Veggie Bus has 100,000 miles on it, has traveled to all of the lower 48 states, and gets six to seven miles per gallon of deep-fried grease.
The exhaust does not, as many people assume, smell like french fries. Nor does it smell like regular exhaust. It is a little danker, with vegetable undertones, since the grease it runs on is used vegetable oil.
But it's not always easy to get your hands on large quantities of quality used vegetable oil.
This became apparent one morning this week, when the bus -- a converted metro model covered in blown-up photographs of mountain climbers, hikers and other vigorous types -- rolled up to the Kendall campus of Miami Dade College, which had generously agreed to donate 75 gallons of the stuff.
The gift filled most of two barrels hidden away behind the cafeteria. It was thick and dark as molasses, with islands of coagulated fat on top, and it would not do.
''There's too much sediment,'' said Matthew Celeste, a 25-year-old outdoorsman who's been on the bus since August. ``That's why a lot of times we go to fondu restaurants, Mexican restaurants.''
Fondu restaurants are great because their oil is used for just one dish before it's discarded. Japanese restaurants also tend to be good. Celeste wasn't sure about Cuban. ``We've never done a Cuban restaurant.''
A food services employee was looking on, apologetically. ''This is not necessarily bad grease,'' Celeste said. ``It's just that they cook a lot of stuff in it.''
The rest of the crew was back at the bus: Paige Chambers, 24, Jessica Blount, 23, and Andy Bassett, 26.
They looked exactly the way you'd expect people driving a vegetable-oil bus to look, which is to say beards on the men, nose rings on the women and ergonomic sandals for all.
NEUTRALIZED
Chambers did a half-hour talk for a class of English students who took dutiful notes but asked and answered few questions. ''Who knows what carbon neutral is?'' she asked. Silence. ``Well, what's neutral?''
These were appropriate questions, because while vegetable oil falls short of the neutral ideal -- its production entails the release of carbon dioxide into the atmosphere -- the fossil fuels that power most automobiles fall much shorter. The point of the Veggie Bus voyage -- a project of the National Outdoor Leadership School -- is to get people thinking about such things.
Also of interest, or not: corn, peanut, soybean, olive and avocado oil work just fine. The oil runs through a series of progressively finer filters, the last of which prevents particulates as small as 15 microns across from entering the engine, a diesel-burning model from Caterpillar that needed no modification to run on vegetable oil.
The second stop of the day was Miami Dade College's medical campus, where public opinion strongly supported the vegetable oil car if, hypothetically, one should come on the market.
''Oh my gosh, yes!'' said Christina Ferrer, 22, a medical lab technology student. ''I'm guessing they would have vegetable oil stations,'' said Maria Medina, 18, a nursing student. ``All the restaurants could donate it.''
And, from Carlos Diaz, a private tutor who pulled up in what might be the only vegetable oil-powered Ford F-350 in Miami: ``I'm not polluting, the cost is nil, and I'm not taking apart countries and leaving thousands of orphans and widows.''
There followed a break for lunch, where Chambers explained exactly what it's like to swallow used vegetable oil that's been sitting in a barrel in the back parking lot of a restaurant for a while, something she did just once.
''You know if you eat french fries and your mouth is just filmy? It was like that, but 5,000 percent worse. I could taste it for a couple of days.'' And then it was time to refuel.
TACO SHOP
Ver-Daddy's Taco Shop had been scouted, on Biscayne Boulevard and 75th Street. Acceleration was smooth on the way over. Miami traffic was horrible.
Two barrels of used cholesterol-free, non-hydrogenated soybean oil waited in back of the taco shop parking lot, gratis, with the somewhat mystified consent of the owner, David Bass.
Normally, his grease is picked up by a recycling company that pays him $10 every three months for the privilege.
He wasn't sure what they did with it -- something to do with cosmetics, maybe.
But nobody had ever pulled up in a bus and asked to fuel up before. ''Never, never,'' he said. ``It's exciting for us -- we're just a little taco shop.''
The crew put on filthy jumpsuits. The barrels were opened, gingerly.
The crew has discovered, in grease vats less wholesome than Ver-Daddy's, dead rats and condoms and chicken bones.
But this was good stuff: the color of honey, with excellent lees. It was sticky to the touch, which was unavoidable, and utterly repulsive. ''I get pretty nauseated from the smell,'' Blount said.
Eighty gallons were ladled from the barrels into five-gallon buckets, hauled over to the bus, siphoned, heated and pumped into the tanks. Another 70 gallons were slopped into buckets stacked in the bus's storage compartment.
This took half an hour, followed by some minutes of vigorous hand washing with a powerful cleaning agent, but everyone agreed the grease had been an excellent find.
''We're going to get out of Florida with that,'' said Bassett.
If you have a story idea, e-mail nspangler@MiamiHerald.com.
