We've already had the chance to drive the latest, all-new C-Class as a mild-hybrid diesel and what Mercedes expect will be the 'go to' model for company car drivers - the C300e PHEV. Both impressed with their comfort, refinement and technology. We've now had the opportunity to drive the biggest diesel - the C300d in UK AMG Line Plus specification.  

It might be badged C300d, but like BMWs, the badging has nothing to do with the engine size, as this C-Class is powered by a 265hp version of the 2.0-litre, four-cylinder diesel engine. Which despite its 5.7 second 0-62mph acceleration figure, 53.3-55.4mpg consumption and licence-losing 155mph top speed, the 32% BIK charge seems quite reasonable. However, with diesel out of fashion, we can't help feeling the C300e with its 8% BIK figure and 403.5mpg consumption, is better suited to fleet. 

The C300d is impressively refined and is a punchy performer, but at higher speed and when being worked, some diesel clatter can be heard - a little too much in fact. Although generally it's fine and well-mated to the 9G-Tronic automatic gearbox, however we did experience some drivetrain shunt between the gearbox and mild-hybrid system when stopping and starting. 

Current Mercedes models have attractive interiors, and the latest C-Class certainly feels like it has the edge over the current BMW 3-Series here. As before, the C300d's dashboard is dominated by the latest MBUX infotainment system, with its iPad-like screen curving out of the centre console. An impressive system, based around personal profiles that you sign into when getting entering the car. We generally wish for some physical controls for the infotainment, but the Mercedes system has top quality graphics, and despite all the features, is simple to use. 

However, like other Mercedes models we've tried this year, the updated "Hey Mercedes" voice recognition system, can be more miss than hit when using some functions. Plus, why does the excellent augmented navigation display obscure the whole screen when making direction changes - couldn't it just be combined in the head-up display, and projected on to the windscreen, just like in the latest Audi models? 

The quality feel carries on to the rest of the C-Class's interior, but despite our AMG Line Plus test car being a UK car in UK specification, it's mixture of black and brown leather trim combination was unusual - but remained high quality. 

Other than this, we feel the rear legroom could be more generous - although there is obviously more room than the old car. The 455-litre boot will be practical enough for most, but it's smaller than the 480 litres you'll get in both the BMW 3-Series and Audi A4. 

Outside, like the inside, the latest C-Class is basically a scaled-down S-Class in terms of looks. With the large grille at the front, with the distinctive three-pointed star logo, it could only be a Mercedes. Overall, it's an attractive, sleek look - although perhaps not as distinctive as Mercedes' all-electric EQ models.  

Being AMG Line Premium Plus spec, you benefit from a 15mm drop in the suspension, and 19in AMG-branded alloy wheels. There are also standard selectable dampers, which do their job particularly well in 'Comfort' mode. Although, the C-Class is generally refined and comfortable - but it is definitely not as sporty as the BMW 3-Series.