It's not uncommon these days for motor-racing enthusiasts to engage in lively debate as they compare CART's Champ Car to a Formula One racer, since both machines are the fastest open-wheeled single-seaters on the planet.

One can only begin to truly appreciate some of the technical subtleties that differentiate these two breeds of race car once their gleaming bodywork has been removed. And racing fans who spend an additional $45 for a paddock pass to the Molson Indy Montreal at Circuit Gilles-Villeneuve on August 23-25 will have the opportunity to draw their own conclusions, as engineers and mechanics tweak these finely tuned machines in plain view in preparation for Sunday's main event.

The following is a brief overview of the differences between the two series:

A Champ Car is slightly longer and wider than its F1 counterpart, since it must incorporate more deformable structures in order to protect the driver in case of impact with the concrete walls bordering oval tracks. The minimum weight of a Champ Car is set at 703 kilos, while an F1 car weighs in at 600 kilos, driver included.

Two manufacturers, Reynard and Lola, supply chassis to the entire 20-car CART field, whereas the 11 F1 teams design and build their own chassis. Engine-wise, CART teams lease power plants from three automotive giants, Ford-Cosworth, Honda and Toyota, while eight different engines power F1 cars.

The Champ Car motor is a 2.65-litre, 8-cylinder turbocharged unit capable of revving up to 16,500 rpm and delivering 800 hp. The engine burns methanol fuel and its power output is controlled by a CART-issued pop-off valve that limits turbo boost to 34 inches of mercury for all competitors in 2002.

F1 uses 3-litre, 10-cylinder non-turbocharged power plants that are fed with unleaded racing gasoline and are rated at 800 hp at and above 18,000 rpm.

All Champ Cars are fitted with Bridgestone Potenza slick racing tires with a maximum width of 25.5 cm at the front and 35.5 cm at the rear. In F1, Michelin and Bridgestone both supply grooved tires that do not exceed a width of 30.5 cm at the front and 35.5 cm at the rear.

Champ Cars run on a wider variety of configurations — superspeedways, ovals, street and road courses — and are capable of reaching speeds in the vicinity of 400 kph on superspeedways, whereas F1 cars mainly race on permanent road courses and can travel up to 360 kph.