Alfa Romeo 690T

Alfa Romeo's 2.9 twin-turbo V6 — the Giulia and Stelvio Quadrifoglio's engine.

⚑ It is a Ferrari V8 with two cylinders removed, and that is the literal design rather than a marketing line: it shares its architecture, its bore spacing and much of its top end with the F154 family. The consequences are real — it is built to Ferrari tolerances, it revs to 7,300, and it is serviced accordingly.

So generic advice about turbocharged V6s is the wrong reference class. Oil grade and interval are not routine here; the specified oil is specified for reasons that show up at the top of the rev range, and an engine run on the wrong one does not announce it until something expensive has already happened.

Its known items are the turbochargers' oil feed and the water-to-air intercooler circuit, which is a separate cooling system with its own pump and its own failure mode: a loss of power under sustained load with no fault code is worth tracing there.

Specialist experience is genuinely thin outside the dealer network, which is unusual for a car this well known — and the reason the factory procedure is worth more here than the community's.

⚑ It is not the F154. That is Ferrari's 3.8 twin-turbo V8, which this engine is derived from — two cylinders fewer on the same architecture — and which has its own page here. A Maserati's V6 is not this engine either: that is the F160. The 690T is in the Giulia and the Stelvio.