Parkers overall rating: 4.5 out of 5 4.5

The 1-Series Convertible gets the pick of BMW's small engines and has a much wider range than the 1-Series Coupe. The petrols range from the 118i, through to the 120i, 125i and the range-topping (and magnificent) 135i. The 125i is one of the most popular petrol options - and with good reason. It's a smooth 3.0-litre engine with 218bhp on offer and comes with a six-speed gearbox.

A great all-rounder, it not only sounds great but is as happy in town as it is driven briskly on the open road and with a 0-62mph time of 6.8 seconds it's rapid too. Thanks to BMWs Efficient Dynamics system none of the engines is overly thirsty and even the performance 135i model is capable of 30mpg. But it's the diesel options which make most sense as not only are they economical but they're swift too.

The 120d manages 0-60mph in 8.1 seconds and offers great in-gear punch while returning 55mpg. The 118d is the most efficient with an impressive fuel economy figure of 58mpg but by far the best engine to drive is the 123d. This uses the same 2.0-litre unit as the two other diesels but with thanks to twin turbochargers delivers more than 200bhp and great low down pulling power.

As a result it's capable of 0-62mph in just 7.5 seconds.

Despite not having a the fixed roof, the 1-Series Convertible has extra stiffening compared to the Coupe and as a result is just as good to drive - even with the roof down. There's minimal vibration or shudder through the cabin, even if you hit a pothole and the bodyshell feels just as stiff as the hard roof version. The suspension is firm - adding to the sporty feel, but still manages to be comfortably supple.

Keen drivers will appreciate the 50:50 weight balance, precise steering and huge amounts of grip and traction while around town the steering is light enough to make parking easy. There is an issue with rear visibility due to the small back window which can make reverse parking tricky.