Aprilia 65° V4 Engine (RSV4 / Tuono V4)

Aprilia's 65° V4 is the only production superbike engine with a cylinder angle between the 90° of Ducati's V4 and the 180° of inline-fours. Its 65° V-angle was chosen to achieve a short engine length while retaining the firing order characteristics that produce the distinctive Aprilia exhaust note. The RSV4 Factory (217 hp) and Tuono V4 (175 hp) share the same engine block, cylinder head castings, and crankshaft — the Tuono's detuning achieved via softer cam profiles and a revised ECU map rather than different hardware. This makes the Tuono the most direct track-to-road transfer of a superbike engine in production.