Exclusively powered by petrol engines, the Mazda6 was the first car in the UK to features Mazda’s cylinder deactivation Skyactiv-G 2.5-litre petrol engine and the Mazda6 is also offered with the 145ps and 165ps versions of the Skyactiv-G 2.0-litre petrol engine. All engines are offered with both Saloon and Tourer models so whatever the body style there’s plenty of choice.
The 145ps Skyactiv-G is matched to entry-level SE-L trim and with the Saloon there’s a choice of manual or automatic gearbox. Step up to Sport grade and the Mazda6 is equipped with the 165ps of the 2.0-litre engine, with this time the Tourer offered with an automatic gearbox. Exclusively offered in flagship GT Sport trim, the Skyactiv-G 2.5 is matched to the six-speed automatic Skyactiv-Drive gearbox. Equipped with Mazda's i-stop and i-ELOOP systems across all engines, the Mazda6 continues to deliver excellent efficiency.
Short for “Intelligent Energy Loop”, i-ELOOP is a pioneering system that stores recovered electricity in an advanced capacitor rather than employing a dedicated battery. The large-capacity electric double-layer capacitor (EDLC) captures and stores energy very quickly during the deceleration phase, which typically lasts only 10 seconds. Used to run the vehicle’s electrical systems, i-ELOOP can improve real-world fuel economy by up to 10% depending on driving conditions.
The i-stop idle-stop system uses combustion energy for restarting the engine, and only requires an electric-powered starter motor to provide a small degree of momentum during the initial restart phase.
With the growing importance of petrol in this segment, with a compression ratio of 13.0:1, Mazda’s excellent ‘right-sized’ 2.0-litre engine offers an ideal balance of fuel efficiency and spirited driving thanks to powerful low- to mid-range torque. A coolant control valve makes warming the engine more efficient, and asymmetrical oil rings in conjunction with barrel-shaped piston skirts reduce mechanical friction. Emissions easily comply with new WLTP test cycles, falling well within the particle number limits without the need for a petrol particle filter.
The lower powered 1,998cc unit develops 145ps at 6,000rpm and maximum torque of 213Nm at 4,000rpm. It combines a combined fuel consumption of 42.2mpg and CO2 emissions of 152-159g/km. The higher powered unit of the same capacity develops 165ps at 6,000rpm and maximum torque of 213Nm at 4,000rpm. Its combined fuel consumption is 42.2mpg, while CO2 emissions are 152g/km.
Even better, with cylinder deactivation technology that shuts down two of the engine’s four cylinders in light load situations, the 2.5-litre Skyactiv-G petrol is an excellent addition to the line-up. Running on two cylinders reduces pumping loss and mechanical resistance to improve efficiency. With a high 13.0:1 compression ratio, the reduced weight of an aluminium-alloy cylinder block, and a balancer unit that reduces low frequency rattling, the 2.5-litre engine achieves high levels of dynamic performance, fuel economy and quietness. It develops 194ps at 6,000rpm and maximum torque of 258Nm at 4,000rpm. It has a combined fuel consumption of 37.2-38.2mpg and CO2 emissions of 167-172g/km.
Across the range of innovative Skyactiv-G petrol engines a host of technologies ensure that the Mazda6 benefits from the very best powertrains. The shape of the intake ports has been carefully crafted to generate a stronger tumble flow during intake. Additionally, reducing the height of the piston crowns, while optimising their shape also strengthens tumble flow during the compression stroke and increases turbulence at the time of ignition. These factors cause the flame to spread faster from the spark plug and combustion is completed more quickly without knocking. The result is greater torque at low- to mid-range rpm and improved fuel economy at higher rpm.
The Mazda6’s petrol engines also benefit from more efficient fuel injection, with the nozzles of the multi-hole fuel injectors and fuel pressure at 30MPa to realise a faster and more broadly dispersed spray. Fuel is thoroughly vaporised before it adheres to the walls of the cylinder to create efficient, waste-free combustion. Three-stage split fuel injection is used when the engine is cold and combustion is more likely to produce particulate matter. This improves vaporisation and atomisation of the fuel and reduces particulate matter formation by approximately 80 per cent. The result is excellent environmental performance that conforms to European particulate number regulations that came into effect in 2017.
Other internal highlights include asymmetrical oil rings that feature a large outer radius at the top and a smaller radius at the bottom edge. This optimises the thickness of the oil film on the wall of the cylinder as the piston rises and falls, reducing mechanical resistance. In addition, the piston skirt curvature realises an ideal barrel shape. The skirts combine with the asymmetrical oil rings to significantly reduce mechanical resistance, contributing to better fuel economy.
A variable displacement oil pumpsupplies the optimum amount of oil to the engine in relation to the engine speed and load at any given time. It uses a hydraulic sensor to monitor the engine for linear control of the solenoid valve to continuously change the amount of oil output by the pump. The supply of oil is therefore reduced at rpms where the engine does not require it, and this reduces mechanical resistance. With a trio of smooth and efficient petrol engines, the simple Mazda6 range offers a wide choice of power outputs.