The VQ35DE is a 3.5-liter DOHC 24-valve V6 engine that was produced by Nissan with idle sound and performance in mind. It debuted in the 2002 Nissan Maxima as the first V6 engine from Nissan with more than 200 hp. The engine was also used in the 2003-2006 Nissan 350Z, the 2004-2009 Nissan Quest, and the 2005-2008 Infiniti G35 sedan/coupe.
The VQ35DE features an aluminum block with cast iron cylinder liners and aluminum heads with dual overhead camshafts (DOHC) and four valves per cylinder (24 total). It has a compression ratio of 10.3:1 and uses forged steel connecting rods, molybdenum coated pistons, and sodium filled exhaust valves. The intake manifold is a plastic composite design which helps to reduce weight over previous designs; it features long runners to promote low end torque. For improved airflow, it uses equal length exhaust manifolds which merge into a single collector before going through the catalytic converter(s) and out the back of the car.
Nissan's Variable Valve Event & Lift (VVEL) system is used on both intake and exhaust sides to improve volumetric efficiency at all engine speeds while maintaining low emissions levels; this allows for better fuel economy as well as increased power output over a traditional non-VVEL DOHC setup. On later models equipped with direct injection, port deactivation is used on one bank of cylinders during light load conditions such as highway cruising in order to further improve fuel economy figures; this effectively turns the engine into a inline-4 until additional power is required, at which point all 6 cylinders are brought back online seamlessly without any driver input or loss of performance.
The base model 2002 Maxima came standard with 185 hp @ 6000 rpm and 205 lb·ft @ 4400 rpm but had an optional Sport Package which bumped those numbers up to 225 hp @ 6400 rpm and 233 lb·ft @ 3200 rpm thanks to different ECU tuning, larger diameter throttle body, revised intake plenum design, higher flow mufflers,and lower final drive gearing ratio (3.69:1 vs 4.08:1).