[motorsportnerd]

DTM - DTM is organised by the DMSB (Deutscher Motor Sport Bund e.V.). The DMSB DTM commission is responsible for the regulations, the ITR (Internationale Tourenwagen Rennen e.V.) for organisation and marketing of the series.
The ADAC controls all motorsport in Germany. Germany's ADAC (which is the German version of the FIA or CAMS). The DTM cars would be the fastest cars around any given racetrack due to much lighter weight than V8 Supercars and therefore better power to weight. The DTM cars also have much better aerodynamices than a V8 Supercar. Engines are 4.0 litre V8s with around 470-500 bhp. Minimum weight is 1050kg. To qualify a minimum of 10,000 road cars must have been built. The cars must be rear wheel drive, though (as in the case of the Audi A4), they can be converted from front or all wheel drive to rear drive. The tyres, brakes, gearbox and electronics are standard components from exclusive suppliers. Electronic driver aids are prohibited. Cars currently competing are Audi A4, Opel Vectra, Mercedes C-Class, Opel Astra Coupe and Mercedes CLK. Audi, Opel and Mercedes all run full factory teams with at least 6 cars each.

BTCC is for 2.0 litre touring cars. Classes are for BTC Touring and FIA Super 2000 cars. Both classes are for 2.0 litre cars. Engines can have a maximum of 6 clyinders. BTC cars have about 280 bhp. Super 2000 cars about 260 bhp. BTC cars weigh about 1250 kg. Super 2000 cars about 1150 kg. Cars can be front wheel drive or rear wheel drive. Gearboxes are 6-speed sequential for the BTC and 5-speed sequential for the Super 2000 cars.
Cars competing currently in the BTC Touring Class are Vauxhall Astra Coupe, MG ZS, Honda Civic Type R, Proton Impain, Peugeot 306, Peugeot 407. Cars competing in the Super 2000 class are Seat Toledo and Alfa 156.
Full manufacturer teams are run by Vauxhall, Proton and Seat.

Then there is the European Touring Car Championship. This is for 2.0 litre FIA Super 2000 cars. Cars involved are Alfa Romeo 156, BMW 320, Honda Accord Euro and Civic Type R, Seat Toledo, Peugeot 307, Ford Focus, Skoda Octavia and Volvo S60.
Manufacturers are Alfa Romeo, BMW, Honda, Seat, Skoda and Seat.

V8 Supercars are explained in FPV's links.

So a rough comparison:
DTM - 470 bhp/1050 kg.
V8 Supercar - 650 bhp/1350 kg.
BTC Touring - 280 bhp/1250 kg.
Super 2000 - 260 bhp/1150 kg.

Of the series, DTMs are the fastest, V8 Supercars probably the most visually exciting, BTCC has the most variety and ETCC has the most manufacturers involved.

The V8 Supercar Series currently has the closest fields (the 32 car field is seperated by less than 1 second in every race) and is currently recognised as the best Touring Car Championship in the world. The DTM would be a close second. The ETCC becomes the WTCC next year and is building support quickly. The BTCC used to be the best series in the 90s, but is now a shadow of its former self. It is gradually rebuilding.

So, there is a summary of the four main touring car championships in the world at the moment.

Official websites:
BTCC - www.toca-tour.co.uk
DTM - www.dtm.de
ETCC - www.eurostc.com

Photos attached are Jean Alesi's 2004 DTM Mercedes, the start of the recent BTCC and ETCC rounds (to tell the difference, BMWs and Alfas dominate the ETCC picture and a Seat and Vauxhalls the BTCC) and Paul Radisich's Falcon V8 Supercar