What is it?
Finally the Infiniti EX has got its first diesel engine, around a year after UK launch, a few months after its bigger FX sibling and the new M saloon, and not a moment too soon by any other reckoning.
There is undoubtedly an appeal to the free-revving, 300bhp 3.7-litre petrol unit, until now the only engine option available in Infiniti’s coupé crossover, but its frenetic, 7500rpm personality is matched by thirst at the pumps.
This new direct-injection V9X diesel engine is identical to the one in the FX30d and loosely related to the unit in the V6 Laguna, but with a new turbocharger, block, crankshaft, intake manifold and sump.
It also has a compacted graphite iron block, both lighter and stiffer than cast iron, which improves refinement and adds strength between the cylinder banks, where the stresses are highest. The single variable-nozzle turbo is mounted in the 65deg vee.
What’s it like?
On the road it’s an impressive, if slightly vocal piece of engineering. For starters, it's got a redline above 5000rpm and spins freely up to it. Peak torque of 406lb ft appears at 1750rpm, which means that you can lock it in fourth gear (roughly 20mph/1000rpm) and dispatch challenging B-roads or motorway sliproads with at least as much ease as in the petrol version.