Jim Bell was scrubbing taxis at the tender age of 10. In 1974, when his high school teachers went on strike, and his friends settled in for some euchre, the teenage Bell started taking some cabbie shifts. To say Jim has cab driving in his blood is an understatement. As the general manager of Diamond Taxi, he's the third generation of his family to helm the Toronto company.

So who better to answer the question: What are cabbies driving these days and why? Are those battered Ford Crown Victorias and Chevrolet Impalas really the zenith of automotive durability?

Turns out, what cabbies drive is the product of zealous regulation and old-fashioned, trickle-down economics.

In much of the country, the local municipality decides what makes an appropriate cab by specifying minimum passenger-space dimensions. Traditionally, city hall has decreed generous in-seam and posterior proportions, requiring operators to run large sedans.

A notable exception is Quebec, where cab owners can use smaller cars like the Chevrolet Malibu and even the Ford Focus to negotiate the old, narrow streets.

In an industry struggling with energy and maintenance costs, profit margins are exceedingly thin. So it's no surprise fleet managers and owner-operators are constantly looking for ways to save a buck.

Cab companies like to buy one-year-old models that have come back from police departments, crown agencies and private security companies. Jim points out that this way, the first buyer has already taken the costly depreciation hit: "Why pay $25,000 for a new one when you can pick up a year-old Ford Taurus for $15,000?"

Numerous players have dominated the taxi market over the decades. American fleets like Chicago-based Yellow and Checker actually started manufacturing their own purpose-built taxicabs in the 1920s. In the 1960s and '70s, Plymouth essentially owned the market with its cheap, bulletproof sedans. "The Plymouth Gran Fury was a tank," Jim recalls fondly.

But Chrysler's near demise in 1980 ended its reign, allowing the stout Chevy Caprice to dominate. Ford countered with its Crown Victoria, which gradually grew more refined and durable. When production of the Caprice ground to a halt in 1996, GM conceded the market to Ford.

More recently, with cities taking a more proactive role in regulating taxi fleets as part of their tourism strategy, taxi companies were often brought to task for running ancient wrecks, some racking up more than one million kilometres before collapsing in a heap of rust and old coffee cups.

Toronto was typical, specifying mandatory retirement after five years on the road. The rule not only put better cars on the street, but a new breed of vehicles the industry had not embraced so easily in the past.

"The industry was reluctant to fall in love with front-wheel-drive cars," says Jim. And for good reason: they fell apart too easily. The old Chevy Lumina and Dodge Intrepid drivetrains couldn't take the pounding of urban driving, recalls Jim, and the manufacturers were criticized for marketing them as 'police- and taxi-grade' vehicles. "They were simply too light," he says.

But with the five-year rule, it suddenly made sense to give front-drive cars a second look. Purchased used, a Buick Century or Ford Taurus only had four usable years left, enough time to put 600,000 km on them before the plates came off. Maybe, cabbies reasoned, the transaxles and engines would hold out just long enough.

Some operators are taking the bet because, for the first time, front-drive cars have made big inroads in the taxi segment. It hasn't hurt that the industry workhorse, the Ford Crown Vic, is getting expensive to buy new or used and it's costly to operate, says Jim. Still, he acknowledges there are some who remain skeptical of front-drive cars.

"The Chevy Impalas run hot -- even with the oil coolers and proactive maintenance done on them, they don't seem to last," says Jim. And despite the recent brouhaha over exploding gas tanks in the Ford Crown Vic, the Ontario-built sedans still own about 80 per cent of the police-car market in North America -- the primary source for many taxi companies.

What does the future hold? Jim says while imports are becoming popular as taxis -- the Toyota Camry and Hyundai Sonata are two common models -- they tend to be driven by individual owner-operators rather than fleet operators. In an industry that relies on bulk purchases and interchangeable body panels, few welcome the expense of maintaining something different and unfamiliar.

"There's very high interest in hybrids," says Jim, "but the jury's still out on the durability question." Everyone's watching a couple of pilot projects in the U.S., using Ford Escapes, to see what the repairs are like. The batteries had better last five years or the economics of hybrids as taxis won't add up, notes Jim.

The bottom line is, it's about the bottom line in the taxi business. Which is not that far removed from most Canadian households, come to think of it.