The “norm” for a V6 is a 60° vee. The PRV runs 90° — not an engineer's whim, but the direct inheritance of the stillborn V8 it descends from. The story of an industrial decision that became the engine's signature.
In 1966, Peugeot and Renault signed an agreement to design common mechanical components; in 1969 La Française de Mécanique was born at Douvrin, and in 1971 Volvo joined the project — P, R and V. The engine the three marques were preparing for their flagships was not a V6: it was a 90° V8 of 3,550 cc.
For a V8, 90° is the natural architecture: it is the angle that suits its crankshaft and its balance. The block, the tooling and the Douvrin production lines were all engineered around that geometry.
Then comes the first oil crisis. A large, thirsty V8 no longer has a future in Europe: the project is abandoned. But rather than starting from scratch, the engineers derive a V6 from it — two cylinders removed, and the 90° architecture kept, along with the studies, the tooling and the industrial investment already made.
That is the whole answer: the PRV is a 90° V6 because it was born a V8. In October 1974, the very first production PRV ran under the bonnet of a Volvo.
A 90° vee on a V6 has a cost: on the first generation, the crankshaft's non-split crankpins made the firing intervals irregular — the origin of the engine's early reputation for roughness. The second generation of 1985 fixed it with split crankpins, bringing even firing.
In exchange, the wide vee gives a lower, flatter engine that slips under low bonnets, leaves room between the banks, and gives the PRV a character all of its own — the one enthusiasts still cherish today, from the Renault 25 V6 Turbo to the DeLorean.
From the 2.7-litre carburettor engines to the 3.0 24-valve twin-turbo of the record: the whole PRV story is on the site.
