V12 engine

A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft.
Since each cylinder bank is essentially a straight-6, this configuration has perfect primary and secondary balance no matter which V angle is used and therefore needs no balance shafts. A V12 with two banks of six cylinders angled at 60°, 120° or 180° (with the latter configuration usually referred to as a flat-12) from each other has even firing with power pulses delivered twice as often per revolution as a straight-6. This allows for great refinement in a luxury car. In a racing car, the rotating parts can be made much lighter and thus more responsive, since there is no need to use counterweights on the crankshaft as is needed in a 90° V8 and less need for the inertial mass in a flywheel to smooth out the power delivery. In a large displacement, heavy-duty engine, a V12 can run slower than smaller engines, prolonging engine life.

Lamborghini's 3512 V12 Formula One engine

V12 engines used to be common in Formula One and endurance racing. From 1965 to 1980, Ferrari, Weslake, Honda, BRM, Maserati, Matra, Delahaye, Peugeot, Delage, Alfa Romeo, Lamborghini and Tecno used 12-cylinder engines in Formula One, either V12 or Flat-12, but the Ford (Cosworth) V8 had a slightly better power-to-weight ratio and less fuel consumption,[citation needed] thus it was more successful despite being less powerful than the best V12s. During the same era, V12 engines were superior to V8s in endurance racing, reduced vibrations giving better reliability.[citation needed] In the 1990s, Renault V10 engines proved their superiority against the Ferrari and Honda V12s and the Ford V8. The last V12 engine used in Formula One was the Ferrari 044, on the Ferrari 412T2 cars driven by Jean Alesi and Gerhard Berger in 1995.
In the late 1960s Nissan used a V12 in the Japanese Grand Prix and again in the early 1990s Group C races.
At the Paris motor show 2006 Peugeot presented a new racing car, as well as a luxury saloon concept car, both called 908 HDi FAP and 908 RC and fitted with a V12 Diesel engine producing around or even surpassing 700 PS (515 kW; 690 hp). This took part in the 24 Hours of Le Mans 2007 race, with a podium finish and very competitive performance, coming in second place after the similarly conceived Audi R10 TDI V12 Diesel originally developed for the 2006 season.