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.