Mercedes-Benz GLA

A few small changes have been made to the updated version of this GLA 250 e Plug-in model.

The output of the electric motor has been raised by 5bhp to 78bhp.

And the PHEV battery is slightly bigger than before, rated at 11.5kWh, as a result of which EV driving range has increased from 37 to 43 miles.

Obviously, you won't get anywhere near that figure if you regularly approach the quoted all-electric top speed of 87mph.

As before, the 150hp 1.3-litre turbo petrol engine combines with the electric motor to generate a surprisingly high level of total output - 218hp and 450Nm of torque.

So, not surprisingly, performance is sprightly, 62mph dispatched in just 7.1s en route to 136mph.

You have to have front wheel drive and an 8-speed 8G-DCT dual clutch auto transmission.

The car has a pleasing preference for battery-powered motoring and there's an extra 'Electric' DYNAMIC SELECT drive mode for use if once you get going, you want to prevent the combustion engine cutting in.

In theory, you can stay in battery drive all the way up to 87mph.

Alternatively, an 'Electric in City' option allows you to save battery charge for urban driving you might want to do later in your trip.

Either way, you can maximise battery range with careful use of these steering wheel paddleshifters, there not to switch gear ratios but to vary levels of brake energy recuperation - though it's easier just to pull hard on either one, this then selecting a radar-based 'D AUTO' recuperation programme which basically does it all for you.

The visual changes made to this revised GLA 250 e model aren't very significant; a restyling for the front grille, the front bumper (with more body colour) and the signatures for the now standard LED-illuminated headlamps.

Plus the wheelarches are now body-coloured and there are revised tail lamps. As before, this GLA's PHEV set-up is all very cleverly packaged.

An innovative exhaust system layout explains the need for a relatively minimal reduction in boot capacity compared with a conventionally-engined GLA model.

The exhaust ends in a centrally positioned outlet under the vehicle floor, with the rear silencer housed in the transmission tunnel.

Integrating the fuel tank into the axle installation space creates additional room beneath the rear seats for the high-voltage battery.

Otherwise, it's much as it would be in any other GLA.

Visual differentiators as to this variant's plug-in status are limited to subtle badging.

Inside, the cabin is unchanged, save for extra EV read-outs on the instrument screen and a comprehensive 'EQ' menu in the MBUX infotainment system.

This revised version of the 'H247'-series GLA isn't much different to the pre-facelift model, though Mercedes has updated the steering wheel (trimmed in soft Nappa leather) and added touch-control buttons.

More significantly, the 10.25-inch MBUX infotainment system has been updated and can now be ordered with fingerprint sensor access.

It also gains more advanced speech recognition and wireless 'Apple CarPlay'/'Android Auto' smartphone-mirroring.

And there are three fresh screen display styles - ''Classic', 'Sporty' and 'Discreet'.

With a GLA 250 e, the instrument cluster monitor will always be of the largest 10.25-inch size. In the back, the PHEV system seems to have brought no discernible compromises in the accommodation provided for passengers.

That's because, cleverly, the fuel tank has been integrated into a space around the axle installation, creating additional room beneath the rear bench for the high-voltage battery.

It all means that, as with an ordinary GLA, leg room's pretty generous by class standards.

But there are compromises in the boot, where the 385-litre capacity is 50-litres down on that of a conventional GLA.

Mercedes has priced this GLA 250 e plug-in at about the same level as the top GLA diesel, the 190hp GLA 220d 4MATIC, which costs around £43,500 but, unlike this PHEV, has standard 4WD.

If you're comparing against a petrol model, for this plug-in hybrid, you'd be looking at needing to find around £2,700 more than would be necessary for a comparably-specified version of the fastest conventional mainstream petrol model, the 224hp GLA 250.

There are three GLA 250 e trim levels - the 'AMG Line Executive' variant, then 'AMG Line Premium' and, if you can stretch up to just over £46,000, top 'AMG Line Premium Plus Night Edition'.

As for rivals, well the most direct one is Volvo's front-driven XC40 T4 Recharge Plug-in Hybrid model, which will save you around £2,500 over this plug-in Mercedes.

The BMW X1 xDrive 25e will also save you money - around £2,500 - and has the added advantage of AWD.

You'll need to pay quite a lot more if you want the premium compact SUV sector's two other PHEV offerings, the Audi Q3 45 TFSI e and the Jaguar E-PACE P300e, but that's because those two cars offer quite a lot more power than this GLA 250e; but they'd certainly come into play as rivals if you were looking at plusher versions of this Mercedes plug-in model.

The new 11.5kWh PHEV battery can be charged with AC or DC current via a socket located in the right-hand side wall of the vehicle.

And in this improved model, it can now be charged at speeds of up to 22kW.

This GLA 250 e's battery can be replenished at a 7.4kW charging station with alternating current (AC) within 1 h 45 min from 10-100%.

A 7.4kW AC garage wallbox needs 3 hours 15 minutes.

Keep everything charged up and Mercedes reckons that 90% of regular commuting journeys can be completed without using the petrol engine.

One important comfort feature is the pre-entry climate control prior to starting a journey, which reduces energy usage and can also be activated conveniently by smartphone.

The quoted WLTP combined cycle fuel figure is 201.8mpg and WLTP CO2 emissions are rated at just 31g/km, which means a low 12% BiK rating and no road tax exposure. The MBUX infotainment system assists the driver in finding charging stations.

Just start a search simply by saying "Hey Mercedes, find charging stations nearby".

Via the 'Mercedes me Charge' system, drivers of this plug-in hybrid model can optionally obtain access to one of the world's largest charging networks, with over 300 different operators in Europe alone (municipalities, car parks, motorways, shopping centres, etc.).

Thanks to navigation, Mercedes-Benz customers can find these stations easily and can gain convenient access to the charging stations via the Mercedes me Charge card, the Mercedes me App or directly from the car.

No separate contracts are necessary for this: apart from simple authentication, customers benefit from an integrated payment function with simple billing after they have registered their payment method once.

Each charging process is booked automatically.

The individual charging processes are clearly listed in a monthly invoice.

If Mercedes could have made this plug-in GLA variant a little more affordable, we'd have had no hesitation recommending it as a go-to model in the range.

After all, there's lots to like here; superb refinement, clean emissions that lead to super-low BiK taxation and the appealing prospect of largely fuel-free commuting mileage.

Even as it is, this GLA 250 e could make more sense than a conventional model once you add up whole-life costs on a finance deal. The era of plug-in hybrid technology may be relatively short-lived - much of Europe plans to ban hybrid engines by 2035 - but right here, right now, it's the approach to electrification that makes most sense for an awful lot of buyers.

But upfront costs need to be driven down if wider consumer uptake on PHEV models like this one is to be realised.

If you don't mind paying the premium though, with a GLA 250 e, you'll get a premium package in return.