THE people who shape the lines of the cars we drive all agree on one thing - the bigger the wheels the better they look.

They may be right, and the owners of Audis and Jaguars in particular seem delighted to find the extra for a set of mega-sized alloys.

And then go in fear of kerbing them expensively on a crowded city street, of course.

Big wheels have long term consequences on other fronts too, notably on fuel economy. Bigger means worse in this case as the wide tyres that make bigger wheels look so good need more power to push them along.

Which is why Kia offers smaller wheels on its hyper-economy Niro model, letting an owner downsize from chunky 18-inch alloys to humbler 16-inch versions, although sadly without charging a bit less for them.

Still, opt to go smaller and you'll still save money longer term as your Niro makes more economical use of its combined petrol engine and electric motor.

The official fuel consumption improves from 64.2mpg to a healthier 74.3mpg and tailpipe emissions fall from 101g/km to a greener 88g/km. That means lower road in the first year (£100 v £140) and a gentler business user tax rate of 17 per cent instead of 19 per cent.

The Niro presents the biggest savings to an owner prepared to plug the car into the mains as often as possible, where a full charge gives up to 38 miles without using a drop of petrol.

Doing precisely that on three nights of my week-long and 545 mile evaluation meant an impressive 73mpg showing on the trip computer. And yes, the car came with the optionally downsized wheels.

You'll also probably help the economy by not treating your Niro like a Silverstone refugee. It might have a sports mode for the auto gearbox but its eagerness doesn't really suit the car.

A Niro buyer will be more impressed by the car's quietness when used with more reserve and enjoy the generous space for passengers and luggage in a well finished but dull looking interior.

The Niro comes in three stages of trim ('2', '3', and '4') with this car's mid-level goodies count lacking for little.

Standard kit includes a fine sat nav system, leather upholstery, heated front seats and steering wheel (lovely on a chilly morning), powered driver's seat, parking sensors to supplement the reversing camera and upgraded JBL sound system.

It also comes as standard with the larger alloy wheels but you might quickly want to delete them on the order form.

Every Niro has cruise control, DAB radio, Bluetooth and Android Auto and Apple CarPlay to keep you thoroughly connected to the outside world.

They also all share a look that its maker hopes lends an air of rugged authority that attracts the name 'crossover' but looks to these eyes like a cross between an estate and sensible hatch.