With Ford’s decision to cancel production of full-size Crown Victorias, Toronto Police filled a rooftop with enough of the cars to last up to three years.

The 300 cruisers cost about $5 million, but the bulk purchase saved taxpayers $1.5 million, according to Const. Tony Vella.

Built only in St. Thomas until production stopped last September, the last North American rear-wheel-drive V-8s were “found to suit our purposes,” Vella said.

Once available privately, “Crown Vics” were produced exclusively for fleet orders in recent years.

Most cruisers were branded “Police Interceptor,” with heavier-duty engines, transmissions and electrical systems, plus revamped steering and rear suspensions.

Big patrol cars were once common, including the Dodge Diplomat, Ford Galaxie, and Chevrolet Caprice.

Toronto Police last bought Caprices in the late 1980s. General Motors stopped producing them in 1996.

Except for special squads that use SUVs and vans, plus tests with other vehicles including mid-size Chevrolet Impalas, Crown Victorias remain Toronto’s patrol car of choice.

The stockpiled white Crowns on the roof of the Traffic Services building in Liberty Village will eventually replace old cruisers. Until then, they are checked and started periodically.

Cop cruisers typically last up to three years before they’re stripped of equipment and sold.

The OPP uses Crown Victorias and SUVs while regional forces have a variety of North American vehicles.

There have been alternatives to the big gas-guzzlers, but smaller GM and Chrysler four-door cars left some officers complaining about gear-jammed interiors, low ceilings, front-wheel drive handling and restricted visibility.

Since Ford’s 2009 announcement of the Crown Vic’s demise, fierce competition began for cruiser markets.

General Motors reprised an old brand in 2010 when it unveiled a V-8 patrol car. Made in Australia starting last year, the new Caprice bears a close resemblance to the GM-related Holden Commodore.

Some U.S. forces ordered the 2011 Holden Statesman. The RCMP use Jaguars and Land Rovers in B.C.

In mid-2010, Chrysler unveiled a 2011 Charger Pursuit, available with V-6 or V-8 motors. Many North American forces use Dodge Magnums and low-slung Chargers.