The new car joins the diesel powered Q50 variants, and will go on sale with a price tag of £31,755. Infiniti says the 2.0-litre, four-cylinder turbocharged petrol engine develops 208bhp and 258lb ft of torque, and is coupled to a seven-speed automatic transmission.
The Q50 performance saloon comes in three trim levels - SE, Premium and Sport. A Q50 hybrid is also available. The new petrol variant is only available with the top two trims.
SE trim, combined with a 168bhp 2.2-litre diesel engine, is the base model for the range. Standard equipment includes 17-inch alloy wheels, keyless entry, a rear-view camera, rain-sensitive wipers, LED lighting at the rear and dual-zone climate control plus Infiniti's InTouch dual-LCD infotainment system inside. The InTouch system features audio driven through a Bose speaker system, with USB/iPod connectivity and voice operation.
Cruise control, speed limiter, stop-start and hill start assist are also included. Safety equipment includes traction control, TPMS and brake assist.
At £30,350, a £2400 premium over SE trim, Premium models get heated leather seats plus an automatic dimming rear-view mirror. More interior trim choices, including the addition of aluminium, also become available.
The highest-spec option in the range is the £32,720 Sport trim. At this level the Q50 gets a redesigned front bumper to give it a more aggressive stance, plus LED lighting all round. Larger 19-inch wheels complete the exterior look.
Inside, Sport trim gives the Q50 aluminium trim, sports seating, and powered steering adjustment. Drivers at this level also get Infiniti's new Direct Adaptive Steering system, which changes the weight and feel of the steering. Active Lane Control is also featured on the Sport.