FOR many years now it's been easy to suggest you buy a diesel engined car if utmost economy is number one on your motoring priority list.

Today, that might not hold true any more. Not only is diesel fuel dearer than petrol, it hits a company car driver harder in the pocket at tax reckoning time too.

But perhaps more important than that is the way petrol engines have come on in leaps and bounds, with more power being squeezed from smaller capacities, to the benefit of both performance and economy (although not always at the same time).

Take the latest version of the popular Meriva, recently modestly updated in looks and now available with a new diesel engine, of which Vauxhall is extremely proud.

Called a 'whisper diesel' by its makers, it certainly keeps its voice down, even from a cold start when diesels are always at their most vocal, and performs well thereafter.

Even so, the vast majority of Meriva buyers are expected to head for a petrol version when they put their money down for a new one. The reason is not hard to find and, yes, it all comes down to economics.

Plump for a new 1.6-litre diesel in your Meriva and it will cost you £2,190 more than taking the 1.4 petrol version that's the subject of this test. Unless you are a stratospheric mileage driver, that's not going to make economic sense.

Bigger cars, aimed solidly at the business driver, will accumulate huge mileages in the course of their three years on the company fleet, so paying more at the start for diesel power makes sense at the end.

Diesels also drive in a different way to petrol powered machines; using their low down pulling power to have the car in higher gears at lower speeds than you'll need in a petrol model, which will need revving to get the best out of it.

But technology, in the shape of a turbocharger which pushes air and fuel into the engine, means the latest petrol engines give surprising shove at low revs. And they'll almost always be quieter than a diesel at a motorway cruise, and much quieter at a cold start in the morning.

Choose either petrol or diesel in the revised Meriva and it will come attached to a gearbox which has been finessed to produce smoother, easier changes. If you tried the change in the previous car you might have thought it was fine already; the new one is fine too.

Away from the oily bits, the Meriva continues to draw potential buyers in with a rear door arrangement that makes loading youngsters mere child's play compared to a car with conventional doors, hinged at the front.

The Meriva's swing open from the rear, a difference that reveals a huge opening and enough space to make loading the nippers into their child seats much less of a back straining exercise.

With the kiddies safely strapped into the rear you won't be driving as though your trousers are on fire, but Vauxhall has given the latest Meriva a mild tweak in the rear suspension department to add to your driving enjoyment.

It's no Grand Prix racer in disguise, even so, but all the better for that. Too often these days any new car seems to need sporting potential to appeal, even when it will spend its day moving children around a city centre.

Good for Vauxhall not to grab the Grand Prix bait and instead tune this modestly sized people mover to the particular needs of British roads.

The new range spreads from £12,620 to £22,355 across six trim levels and can include extra cost features like a full length sunroof or headlights that shine around corners.

As ever, the value in the range lies nearer the bottom than the top and comes with a tank ready for a fill of petrol.