At the start of 2014, I was coming around to replacing a Vauxhall Ampera and, although I’d got on well with it, I was getting a sense that the powertrain was about to start ageing badly. The Outlander PHEV offered as much range without the practicality sacrifice, while the i3 REX travelled twice as far on battery power and, like the Mitsubishi, it had rapid charging. This, I predicted, would be the standard going forward.

I got that one wrong. Five years on, most PHEVs are only now catching up with the Ampera’s EV range, and even some of the newcomers only offer 3.6kW charging. I know rapid charging isn’t essential when you’ve got a combustion engine to fall back on, and I know it adds cost to an already expensive car, but if the goal is to reduce fuel consumption then surely it makes sense to have it as an option? Particularly for luxury marques.

Some etiquette here. I’ve watched a Dutch-plated Tesla queue at an Electric Highway point near Cardiff, waiting for an unattended C-Class PHEV to trickle charge on the AC side. I’ve also had the heart-sink moment of rolling into a motorway services in a range-depleted EV to find the rapid charger occupied by a plug-in hybrid. So I’ll always leave a note with my mobile number in case someone wants me to move, but I’m also making the effort to plug in where possible as it’s worth doing so in this car.

The Outlander has a Chademo connector offering DC charging at up to 22kW. I’ve been getting an indicated 20kW on Electric Highway points I’ve used so far, which is easily enough to get most of its range back in around half an hour. However, the networks are better suited to full EVs, which offer at least twice the charging speed, are typically more energy-efficient, and are reliant on rapid chargers for longer journeys. So the cost benefits are tight if you’re in a PHEV.

Rather like buying fuel at motorway service stations, roadside rapid charging is a convenience and thus attracts a premium. It costs 30p per kilowatt-hour to top up at an Electric Highway point which, with indicated lifetime average energy economy of 2.5 miles per kilowatt-hour, equates to around 12p per mile on electricity. This isn’t cheap, but neither is the alternative. The Outlander averages around 38mpg once the battery range has depleted, or 14p per mile based on the AA’s most recent average fuel price report.

So it’s tight, but I should stress here that I’m not pulling out all the stops. I’d pay half as much per kilowatt-hour to use the Electric Highway if I switched to an Ecotricity home energy tariff, for example, which makes a clear-cut business case for plugging in. BP Chargemaster also offers “just off the motorway” rapid charging for 10.8p per kilowatt-hour, albeit with a £7.85 monthly fee for Polar Plus membership. Given that this also offers free access to slower “destination” chargers, committed Outlander drivers ought to be able to claw back the membership fee fairly easily.

Frankly, I’m determined enough to use the car properly that even the slightest cost benefit feels like a bonus. Rapid charging might not have become the norm for plug-in hybrids, but I still believe it’s a useful and underrated feature for those who care about using these cars as intended.

This year marks the fifth anniversary of Mitsubishi’s first Outlander PHEVs arriving in the UK. It’s become so ubiquitous since (more than 40,000 sales and counting) that it’s easy to forget just how forward-looking this car was back in 2014 – a low-CO2 SUV, launched with enough of a head start that some manufacturers still haven’t caught up. In 2013, the total UK market for plug-in hybrids was around 1,000 cars – in an incomplete 2014, Mitsubishi alone sold ten times that volume.

Granted, that early lead has been a bit of a double-edged sword. On the one hand it’s been a practical route into plug-in motoring for thousands of motorists, many of whom wouldn’t have been willing or able to go fully electric. On the other side, heavy incentives and a steep learning curve – particularly for fleets – have resulted in some unfair criticism as a result of poorly-deployed early cars. This has never been a straight swap for a diesel engine for high-mileage drivers, and what’s the point of a plug-in hybrid if you never plug it in?

Of course, competition has expanded significantly in the last five years, and the Outlander has upped its game to match. Last year’s heavy technical update (launched, frustratingly for Mitsubishi, just before the UK’s Plug-in Car Grant for PHEVs was withdrawn) effectively renewed most of the hybrid system. Significantly, the larger capacity battery, more powerful motor-generators and a new 2.4-litre Atkinson cycle petrol engine all helped keep CO2 emissions under 50g/km, despite that data being converted from figures derived under the tougher new WTLP fuel economy test. This was a major overhaul, despite being hidden beneath a subtle styling change.

So, can the car that put plug-in hybrids into the mainstream still cut it today? We’ll be spending the next few months tasking a range-topping 4HS model with the rigours of family and business life – long journeys included – to get a feel for how effective those updates have been. And it all starts with unboxing that Type 2 cable stored in the boot.