Fiat's bigger 500L aims to grow up as part of your family, says motoring editor Andy Russell.

For many people a car becomes an essential and valued member of the family. And Fiat is keen for owners to become valued members of its family – in this case the 500 family.

The 500 has grown to accommodate and, hopefully, retain growing families with the launch of the 500L, partly aimed at those who have grown out of rather than fallen out of love with the little 500 and need something bigger as their own family's transport needs also grow.

MINI's larger, more practical, five-door Countryman was a first for the brand and has proven a big hit with customers, appealing to those who want the cute character and kudos of the brand in a bigger package. It's not as sexy or trendy as the smaller, three-door hatchback but for many people the badge is brand is the attraction.

With the Fiat 500, another reborn iconic blast from the past that is a key model for the Italian car-maker and rival to MINI, it's a natural move to grow the model range in size and number.

It has actually developed three offerings as stepping stones for 500 owners needing to move up into something bigger and those who want a versatile, viable option.

Enter the Fiat 500L – that's L for large (hence the advert where everyday objects have also been scaled up) – which aims to take the 500's desirable design to a new dimension. There's also a Trekking version with chunkier sport utility vehicle body styling and a compact seven-seater MPW model.

At first glance it's hard to think of the 500L as an extension of the family but spent time with it and it too grows on you as you tune into the 500 ethos brought out in styling cues and a range of customisation options which have helped make the smaller 500 such a big hitter.

It may dwarf its 500 sibling but the L version is no monstrous multi-purpose vehicle although it is surprisingly roomy inside.

Fiat's strength has always been small cars and small engines and the 500L uses a 105hp version of the two-cylinder 875cc turbo petrol TwinAir unit alongside the four-pot 95hp 1.4-litre petrol and 85hp 1.3-litre and 105hp 1.6-litre four-cylinder turbo diesels. All do the job but if you regularly carry a full load and do higher mileage then the bigger diesel fits the bill.

It's not the smoothest or quietest diesel when you work it but make the most of the low-down pulling power and it's a reasonably refined travelling companion that will return 50 to 55mpg in everyday driving helped by Start&Stop as standard while 21,000-mile/two-year service intervals should help keep running costs down.

Being bigger, it's not as much fun to drive as the 500 but is confident cornering with not too much body lean and steers accurately and responsively for a safe, sure-footed, rather than exciting, feel and that's what you want from something practical carrying your nearest and dearest and other precious cargo. The ride which impresses with its supple big-bump control and smooth, hushed progress even on pock-marked roads which you are aware of but never troubled by it.

The 500L is the most space-efficient car for its size with a light and airy cabin and versatile load bay that are real selling points for families. The high roof gives loads of headroom while sliding 60/40 split rear seats allow legroom and load space to be varied. Even with the rear seats in their most forward position small adults can travel in acceptable comfort if those in front are not greedy with their ample accommodation – slide those rear seats right back and you can happily carry basketball players.

Unfortunately the seats are a bit flat and slabby and the materials geared to be hard-wearing but they should prove durable and easy to clean – music to the ears of anyone who carries children with sticky fingers. And that's the impression with the whole cabin which has been designed to be functional rather than fancy with some fun touches.

The 400-litre boot has a usefully low sill and wide opening to make loading a doddle – up to five suitcases or a full-size pushchair. The standard Cargo Magic Space, a two-level shelf that easily slides into place at sill height or further up the flat-sided boot allows fragile and heavy, clean and dirty or wet and dry loads to be kept apart. Take it out and you have a deep load space.

The fascia is clear and simple with sensible, chunky controls but I found the upright driving position a compromise – difficult to have both seat and steering wheel at the ideal height without obscuring the top of the speedo and rev counter. Large windows and slim pillars make for good all-round visibility.

Cabin storage is the name of the game in any vehicle geared up for family life and the 500L has 22 handy compartments including a twin glovebox.

All models get air-conditioning, six airbags, electronic stability control, five-inch touchscreen radio, Bluetooth, steering wheel audio controls, remote locking, electric front windows and mirrors and cruise control. Pop Star and Easy models are priced the same but the former has a vibrant, youthful feel with body-colour dashboard, bright seat design, chromed side mouldings and 16in alloy wheels while the latter is more comfort focused with a soft-touch dash, two-tone steering wheel, electric rear windows, rear parking sensors and steel wheels. Range-topping Lounge costs £1,400 more and includes suede dash, dual-zone climate control, alloys, automatic lights and wipers, auto dimming rear view mirror, fog lights, parking sensors and rear electric windows.

The 500L adds fun to function in the compact multi-purpose vehicle sector. It won't be to everyone's tastes but its character will make it a family favourite with those people who want a practical car that is still cute and quirky.