Infiniti's new 3.0-liter V6 twin-turbo engine

Infiniti heads into 2016 with an all-new 3.0 litre V6 twin-turbo engine that aims to deliver performance together with efficiency. Drawing on Infiniti’s decades of experience with V6 mills, the new engine in the VR series claims to offer a level of driver engagement using increased power and torque than previous engines.

The engine comes in two flavours, 300 or 400 hp, packed into a lighter and more compact block. Drawing on the VQ series design, the VR delivers 400 hp at 6400 rpm and 475 Nm maximum torque at 1600-5200 rpm. Meanwhile, the lower rated engine puts out 300 hp at 6400 rpm and 400 Nm torque at 1600-5200 rpm.

While looking outwardly identical, the 300 hp version is fitted with a single water pump, while the 400 hp V6 runs two pumps to deal with the increased output. In addition, the new engine uses an optical turbo speed sensor to get that power by allowing the turbine blades to spin faster, up to 220,000 rpm at a steady state. This lets the twin turbochargers produce high output numbers while still maintaining fuel efficiency. The turbine blades have also been designed to minimise lag, allowing the driver to get immediate response from the engine when required.

Developments in the design of the water-cooled intercooler system also enhance performance and efficiency. Rapid cooling of intake air reduces turbo lag and gives immediate acceleration. A secondary benefit is the new design is compact, allowing for a shorter flow path for air entering the turbocharger to enable quicker engine response. A new electronic wastegate actuator provides close control of exhaust gas flow, restricting the amount of exhaust gas flowing through the turbos to improve overall engine efficiency.

The 3.0 litre V6 twin-turbo engine weighs 194.8 kg, dropping 14.1 kg from the previous engine. The new turbo system and intercooler piping add 25.8 kg, giving a total engine weight of 220.6 kg. This lower weight contributes to engine efficiency, and this is carried on inside the engine with the adoption of a new low-friction “mirror bore coating” for the engine block and integrated exhaust manifold for cylinder heads that claims to reduce mechanical friction by 40%. This makes the V6 the cleanest and most fuel-efficient engine of its type that Infiniti has offered, contributing towards the 6.7% improvement in fuel economy, according to Infiniti.

Another feature is a new integrated exhaust manifold, built into the cylinder head, putting the catalytic converter closer to the exhaust header. This results in a shorter flow path for the hot exhaust gases, allowing the catalytic converter to heat up almost instantly – twice as fast as previous V6 engines – and reducing emissions from a cold start.

The new 3.0 litre twin-turbo V6 engine is expected to enter production in 2016 and will be manufactured at the powertrain plant in Iwaki, Fukushima, Japan. The 2016 Infiniti Q50 sports sedan will be the first to have the VR engine installed.