Under CX-7’s sporty suit of clothes is Mazda’s high-performance MZR 2.3-litre DISI turbo, which is the same engine used by the sporty flagship models, Mazda6 MPS and Mazda3 MPS. In this latest guise, the engine produces maximum power of 191 kW/260 PS at 5,500 rpm and up to a maximum 380 Nm of torque at just 3,000 rpm.

Characteristics like high speed acceleration feel and stability were specially optimised during extensive testing on some of Europe’s toughest roads to ensure that European customers get the most out of this high-performance engine.

The engine injects fuel directly into the combustion chamber at pressures up to 115 bar, which causes a cooling effect when the fuel vaporizes. This improves load efficiency and increases torque by about 10 percent compared to a similarly sized engine with indirect injection. Improved load efficiency also has the advantage of increasing the rotational speed of the turbocharger’s compressor blades, which allows nearly all of CX-7’s high torque to be delivered at lower engine speeds of around 2,500 rpm. This ensures instant pedal response, linear acceleration, a 0-100 km/h time of 8.0 seconds, one of the segment’s best, and a top speed of 210 km/h. The vehicle’s modest kerb weight for its class, 1,770 kg (including a 75 kg driver) contributes to this high performance level.

The efficiency of the MZR 2.3-litre DISI turbo is further improved by sequential-valve timing (S-VT), which optimises intake valve opening and closing according to actual running conditions. S-VT is also used to retard ignition timing to raise exhaust-gas temperatures and is combined with a lightweight, single-scroll turbocharger that limits heat loss in the exhaust system and a large intercooler. This helps Mazda CX-7 to achieve competitive emission performance by heating up the catalytic converter fast.

The 2.3-litre DISI turbo features material and design enhancements of various engine components to ensure that all moving parts are stronger, more rigid and durable – and able to handle the increased temperature and high torque output. The cylinder block and cylinder head are made using a new implementation of the Advanced Precision Mazda Casting process, which increases their strength. The crankshaft and connecting rods are made of steel, the diameters of the connecting pins increased, the shape of the rods optimised and full floating pistons introduced. In addition, cross-drilling between the block liners and between the valve bridges on the cylinder head improves heat dissipation and resistance to overheating.

Special effort was made in tuning the CX-7’s exhaust to optimise torque output and to deliver an appealing exhaust tone that heightens the Zoom-Zoom driving experience. The shape and size of the inner diameter of the exhaust pipes and the internal structure of the silencer produce a throaty, sporty sound when accelerating from a standing start or from a low speed, and a pleasing sporty note at high engine speeds.

The Advantages of Direct-Injection Petrol + Turbo charger
Most petrol turbocharged engines have indirect injection, meaning fuel is mixed with air in the manifold before being injected into the combustion chamber. The turbo charger tends to heat up the intake air and when compression in the cylinder increases the temperature even more, engine knock can occur.

To compensate for this, a lower compression ratio is used, but this reduces low-rev capabilities and acceleration. Mazda’s high-tech DISI turbo, however, injects fuel directly into the combustion chamber which forms a highly homogeneous air/fuel mix very close to the spark plug before it is combusted. Upon combustion, a cooling effect is realised in the chamber that keeps temperatures from rising and improves load efficiency at an early stage in acceleration resulting in a quicker supercharge making torque available at lower engine speeds.

This lower temperature also prevents misfire and allows the use of a relatively high compression ratio of 9.5:1. A higher compression ratio helps keep fuel consumption at acceptable levels – Mazda CX-7 uses 10.2 litres of fuel per 100 km/h (combined) – while delivering high torque at low engine speeds and lively acceleration.

Environmental Compatibility – Low-impact Manufacturing
For almost a decade now, Mazda Motor Corporation’s manufacturing facilities have undergone continuous improvements to lower their environmental impact and are all certified under strict ISO 14001 standards. One of the latest developments in this ongoing process of improvement is Mazda’s unique three-layer wet paint system, which bakes primer, base coat and clear coat layers all at once. This lowers the amount of volatile organic compounds used for the Mazda CX‑7 by 50 percent and also CO₂ emissions are reduced by 15 percent.

Enhancing the driving experience is a six-speed manual transmission exclusive to the European version of the Mazda CX-7. It is based on the same sporty transmission from the Mazda6 MPS and features a compact, three-shaft design and CX-7 specific gear ratios that allow full exploitation of the engine’s power. Sixth gear is engineered as an overdrive, which lowers engine revs, optimises fuel consumption and reduces engine noise during high speed driving on the motorway. First, second and third gears have triple-cone synchronizers and fourth gear has double-cone synchronizers, which support smooth, responsive shifting. The result is a manual transmission that is fun to drive on a daily basis, easy to shift, with short, precise shift travel.