Unusually in the sports car field, power isn't really all that important when it comes to Mazda's MX-5. There will obviously be raving performance nuts out there that yearn for turbocharging, a V6 engine or both to launch the little roadster off the line but they're missing the point. The MX-5 produces enjoyment through the oneness it assumes with its driver. Rocket ship acceleration isn't necessary, just a sunny day and a contorting B-road. That's why the MX-5's entry-level 1.8-litre engine option could be the pick of the bunch.

Part of the essential joy of this MX-5 is its predilection to be ragged within an inch of its life. Neither of the car's two engine options produce straight line performance that you could call blistering but, in common with many Japanese petrol units, they urge drivers to push the revs to the red line in each gear. The reward for adopting this 'foot in the corner' policy should be a high-pitched growl from the engine with a rich exhaust accompaniment. Mazda conducted extensive sound tuning on the car to perfect the acoustic experience but the 2.0-litre 158bhp unit still sounds duller than you might hope. The 125bhp 1.8-litre alternative is far sweeter and rewards hard driving more vocally.

With a 0-60mph acceleration time of 9.4s, there's plenty of scope to explore the 1.8-litre MX-5's potential without entering licence confiscation territory. The 2.0-litre unit is capable of 0-60mph in 7.9 seconds which is still fairly tame by today's standards. Neither car will trouble any of the top-line hot hatchbacks that are currently available in a traffic light face off. The entry level car has a 122mph top speed compared to 130mph in the range-topper.

Both of the MX-5's engines use a double overhead camshaft, four cylinder, 16-valve configuration but the 1.8 does without the sequential inlet valve timing system found on the 2.0-litre. The performance difference isn't too dramatic, although the 2.0-litre feels significantly stronger through the mid-range thanks to its 188Nm torque rating at 5,000rpm - the 1.8 manages 167Nm at 4,500rpm. There's little difference between the two on fuel economy, the 1.8 averaging 38mpg and the 2.0-litre 36mpg.

"Part of the essential joy of this MX-5 is its predilection to be ragged within an inch of its life."

Priced at £15,665, the standard MX-5 1.8i is £1,000 cheaper than the equivalent 2.0i model. It features a vinyl soft top, 16" steel wheels, body-coloured bumpers, ABS, twin front airbags and an alarm/immobiliser system. Buyers also receive electric windows, remote central locking, CD stereo, height adjustable steering column and heated electric door mirrors. In the 2.0-litre, aside from the additional performance, your £1,000 buys you a limited slip differential, dynamic stability control, traction control and side airbags.

Drop the top and the wind blocker mounted between the seats does a great job of keeping elaborate hairstyles intact. There are even special modes on the ventilation system designed specifically for open-topped driving. The whole process of folding and deploying the roof is remarkably simple. Mazda claim you can detach and fold the canopy back in six seconds but that's a highly conservative estimate. Unclip a catch, fling the roof over your shoulder and you're there. Putting it back up when the heavens open is similarly straightforward and only requires a little more effort.

The driving position in the MX-5 is low and comfortable with a good degree of adjustment to accommodate drivers of various proportions. The seat slides fore and aft a surprising distance given the comparatively limited space and the steering column adjusts for height. The gearbox with its short, stubby lever is a real pleasure to use delivering a punchy feel. One drawback is that the top section of the shifter had a tendency to twist round in your hand on our test model.

The steering is key to the whole MX-5 experience and, true to form, it's keen and accurate. You can point the car into corners with confidence and small adjustments provoke an almost instant response. This MX-5 is no less than 47 per cent stiffer than its predecessor, which helps reduce the flexing and shuddering often evident in roofless cars. Over the bumps and through the corners, the MX-5 never feels less than solid but the damping is well resolved and the MX-5 remains very comfortable when cruising at low or motorway speeds.

Today's MX-5 is only 10kg heavier than the old model thanks to what Mazda call their 'gram strategy'. Essentially, if it was possible to shave as little as a gram from the weight of a component, they did it. This painstakingly strict diet regime has obvious benefits with regard to handling, performance and fuel economy but it's been brought in with no apparent shortcuts taken in terms of build quality. The interior is well put together along simple design themes. The interlocking aluminium rings of the instruments are a standout feature and the clearly laid-out centre console controls are easy to fathom.

Regardless of the model they plump for, it's hard to see how any keen driver could be disappointed with the Mazda MX-5. The car is everything that a good roadster should be - light, responsive, agile and charismatic. The 1.8i entry level model offers most of the driving enjoyment of the more expensive 2.0-litre with the added benefit of a naughtier engine note. It lacks a little of the range-topping car's refinement when cursing and some of its mid range muscle but on the quiet B-roads where roadsters are meant to be driven it's just as adept. Drive one for a succinct lesson on why power shouldn't be the priority in sports cars.