A look at the vehicles in the Pikes Peak International Hill Climb

As the second-oldest motorsports event in the U.S. to only the Indianapolis 500, the 85th Pikes Peak International Hill Climb will pit racers against altitude, weather, tricky terrain and the clock Saturday.

The 12.42-mile “Race to the Clouds” will feature 56 drivers and 109 riders competing in 19 divisions distinguished by engine size and various modifications.

Practice begins Tuesday, but competitors spent Monday undergoing technical inspections at the Sheraton Hotel. Inspectors took a close look under the hood. We take a close look at each of the classes.

Car Divisions

Unlimited

Nicknamed “Monster,” Japanese driver Nobuhiro Tajima will race solo in this division. With its carbon fiber body and 1000 horsepower, Tajima's Suzuki Grand Vitara has been custom-built for the Hill Climb. The car cost more than $1 million to make and produces nearly 1,000 horsepower through a twin-turbo V6 engine. Tajima crashed on the last practice day last year but still was declared the overall winner on a weather-shortened course.

Mini Sprint

A smaller version of the cars in the open-wheel diviision, this car is allowed 2-wheel drive. The engine is situated in the middle or rear of the vheicle and can have a maximum of 220 cubic inches and six cylinders.

Open wheel

These cars usually sport V-8 engines and 600 horsepower or more. Like Mini Sprint cars, these do not have fenders over the tires.

Pikes Peak Open

These cars resemble common foreign and domestic car models found on the open road. The engines must be produced by the manufacturer, but adjustments can be made to the engine, exhaust system, frames, suspensions and brakes.

Time Attack

Known as rally cars, these turbo-charged cars have been popularized by movies like 'The

Fast in the Furious.' Adjustments are limited, most competitors add roll cages, racing seats and try to stiffen the chassis. Altogether, the cars are 'street-legal' and not too different from those on the showroom floor. Rhys Millen, one of this week's competitors, appeared in 'The Fast and the Furious: Tokyo Drift.'

Exhibition

This division showcases vehicles that don't fit in another category, such as big rigs.

High Performance Showroom Stock

Three V10 diesel Volkswagen Touaregs, just like those found at the dealer, will take on the mountain. No adjustments have been made to the cars and their relative weight will make them one of the slower vehicles on the mountains. One of the drivers, Chris Blais, was the top American finisher in the Dakar Rally, an off-road race from Lisboa, Portugal to Dakar, Senegal.

Super Stock Car

A division dominated by local racers, these American-made cars resemble NASCAR vehicles in that they have the body styles of typical cars but have specially built frames, chassis and engines.

Pro Truck

Typically raced in the Baja Protruck Series, these trucks are competing in the Hill Climb

for the second year in a row. They have specially constructed frames and high performance components like specialized suspensions disguised within a stock body. The small block V-8 engines are consistent between the trucks.

Motorcycle Divisions are divided by the engine size. For example, the 450 division includes motorcycles with 450 cubic centimeter sized engines. (Exhibition 150, 250, 450); (Supermoto 450, 750, 1200)

Like motorcycles, all-terrain vehicles - called "quads" because they have four wheels - are divided by engine size. (Quad 450, Quad 500)

Sidecar

Three sidecars will compete in this year's Hill Climb. The rider steers while his co-driver leans out of the sidecar to help balance the motorcycle as it heads into the turns.

Vintage

With bodies dating back to 1974 and earlier, these twin cylinder motorcycles have engines ranging in size from 650 to 750 cubic centimeters.