The core structure of the 3.0-liter V6 twin-turbo engine weighs 429.5 pounds (194.8 kg) – 39.1 pounds (14.1 kg) less than the engine it replaces. The new turbocharger and advanced intercooler (or CAC) system componentry adds just an extra 56.9 pounds (25.8 kg), for 486.3 pounds (220.6 kg) total.
The all-new power unit is 19 percent (0.7-liter) smaller in capacity than earlier V6 engines offered by INFINITI. It builds on the company’s legacy of embracing new engineering solutions and technologies. Just as these earlier engines have always been respected for their lightweight aluminum construction and low mechanical friction – making them smooth, durable and highly responsive – the 3.0-liter V6 twin-turbo engine follows its performance-oriented predecessors with a more compact and lightweight design, while maintaining a performance focus.
Chief among the new weight-saving elements is the adoption of spray bore coating for the engine block and integrated exhaust manifold for cylinder heads. Not only does this make the engine lighter, but this also aids cooling as heat can dissipate more effectively through the aluminum alloy bore wall, a process boosted further by its physical design, which encourages faster engine heat management.
The lower weight throughout the engine contributes to greater mechanical efficiency, with lower inertia from its lightweight aluminum components, while this added efficiency adds to the drivability and overall performance of the V6 engine.
The engineers have adopted a series of innovation technologies for application in the new V6 to deliver a more engaging driving experience. Chief among these is a new direct-injection gasoline (DIG) fueling system. The high-pressure DIG system allows for more precise injection of fuel into the combustion chamber, delivering the exact amount required for smooth engine acceleration, depending on throttle position and engine speed. This system makes the new V6 the cleanest and most fuel-efficient engine of its type that INFINITI has ever offered, contributing towards the 6.7 percent improvement in fuel economy.
The advanced valve timing control allows for more precise regulation of the fuel and air mix in the combustion chamber, helping the engine to operate more efficiently and improving fuel economy under all conditions.
The new cylinder-bore coating process further boosts mechanical efficiency. The new low-friction “mirror bore coating” technology allows the pistons to move more freely in the cylinders by reducing levels of mechanical friction by 40 percent compared to the previous V6 engines. This mirror bore coating process involves cylinder walls getting treated with a thermal arc spray coating after which the coating is hardened. The “mirror-smooth” cylinder wall reduces piston friction and boosts performance.
The mirror bore coating process saves the 3.0-liter V6 twin-turbo engine 3.8 pounds (1.7 kg) in weight, when compared to previous V6 engines, owing to the hardened tolerance that the spray system gives to lighter metals.
One of the most significant features in the all-new 3.0-liter V6 twin-turbo engine is the adoption of a new integrated exhaust manifold, built into the cylinder head, enabling engineers to position the catalytic converter closer to the exhaust point. 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.
Moving the catalytic converter closer to the exhaust point saves weight by making the engine more compact than before. This design accounts for an 11.7-pound (5.3 kg) reduction in weight.
The new aluminum engine block has been constructed as a “square” engine, with equal cylinder bore and stroke dimensions (86.0 x 86.0 mm). As a result, the 3.0-liter V6 twin-turbo engine combines low mechanical friction and fast-revving response. Power and torque are accessed across a broader spread of mid-range engine speeds, in which drivers typically spend most of their time. The result is, the ideal balance between drivability, efficiency, and performance.