The petrol version is another V6 but with a 3.7-litre capacity that produces 315bhp. It’s marginally quicker than the diesel and will reach the 62mph benchmark from standstill in 6.2 seconds. For pure Infiniti M performance it’s the pick of the two engines and once up to speed it delivers a lovely V6 gurgle. It’s got enough punch to make overtaking incredibly easy and with a limited top speed of 155mph it’s the perfect cruiser. The other petrol engine in the Infinti M is a 3.5-litre V6 that is coupled to an electric motor, which gives this model four-wheel drive. With 359bhp on tap, it delivers 0-62mph in 5.5 seconds and heads on to a 155mph top speed.

Diesel engine

The 3.0-litre V6 diesel engine in the M30d is the same one found in the manufacturer’s EX model and comes with 235bhp, covering the 0-62mph sprint in 6.9 seconds. It’s a decent engine with plenty of low-down pulling power and acceleration that’s every bit as good as its German competitors. It offers a fine blend of efficiency and performance and is particularly good for anyone who spends a lot of time on the motorway. On diesel models eco mode alters the gear ratios and also has the added novelty of warning lights that tell you when you are driving too aggressively.

Parkers recommends

We should be telling you to go for the diesel, as we would with most executive saloons, but the M35h hybrid is the one to choose for its economy, emissions and performance.

Despite Infiniti claiming the M to be a car ‘developed by drivers for drivers’ it’s not as engaging as the 5-Series, offering a more sedate experience that’s similar to the E-Class. This doesn’t mean it’s completely devoid of feeling: the steering has enough weight to give a rewarding experience and the S versions that come with four-wheel active steering and sports suspension are very agile on turn-in.

The ride is smooth, especially on well-maintained roads but on poorer surfaces – especially on 20-inch wheels – things do get a little rough.