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Better fuel effi ciency & cleaner emissions

Friction reducing measures, including the world’s fi rst use of hydrogen-free diamond-like carbon (DLC) in a production vehicle, and enhanced combustion effi ciency give the new VQ engine better fuel effi ciency and cleaner exhaust emissions.

As one of the ways to minimize friction on critical moving surfaces, Nissan has adopted a hydrogen-free diamond-like carbon (DLC) coating for the valve lifters. This application of nanotechnology provides an extremely slippery fi nish, which results in a dramatic 40% reduction in friction. Use of an oil additive developed for DLC applications creates a more durable ultra-low friction lubricating fi lm. The resulting reduction in cam lifter friction signifi cantly boosts fuel effi ciency.

Hydrogen-free DLC coated valve lifters

The crankshaft and camshaft journals are critical components for engine performance. Therefore, the VQ engine employs journal surfaces fi nished with polishing tape and lapped to create a mirror-smooth surface. This is another example of how friction is minimized throughout the VQ engine.

Mirror fi nish

Crankshaft journal

Hydrogen-free DLC coating

Cam contact surfaceUltra-low friction lubricating fi lm

Hydrogen-free DLC coating

Substrate

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VQ35HR•VQ25HR EngineTechnology Overview

The smaller the fuel droplets sprayed by the injectors, the better the fuel mixes with the air to support more complete combustion and reduce unburned hydrocarbon (HC) emissions. The new-generation VQ engine employs injector nozzles having 12 holes (of 130µm diameter each), up from the previous 4-hole (250µm diameter) format. This multi-hole high-atomization design provides broad dispersion to raise combustion effi ciency.

Nozzle plate (injector tip)

Atomizing fuel injector

Atomizing fuel injector

The spark plug’s center electrode has an iridium alloy tip for high ignitability. This helps achieve cleaner emissions by stabilizing combustion when starting the engine.

Super-ignition iridium spark plugs

Super-ignition iridium spark plug

Iridium center electrode

Platinum ground electrode

Conventional 4-hole type New 12-hole injector

250µm diameter 130µm diameter