Plug-ins: are they a real hope or a future fantasy?
* They can go 50km on an electric charge, merely sip fuel from the tank but transform into fast and fiery performers when called upon. Welcome to the weird and wonderful world of plug-in hybrids, as Eddie Cunningham asks: can they help solve our emissions problem or are they just another fad?
They are, without doubt, one of motoring's most fascinating treble acts.
Plug-in hybrid vehicles (PHEVs as they are known) can do things no other cars can. But are they a realistic option for an ever more tightly-regulated emissions future?
Or a fad that will fizz for a while before yielding to the next great thing?
Right now a lot of car makers are focussing on the positive and betting loads of development money that the plug-in is here to stay - and feel they need to be part of it.
Others are not so sure and wait, from the sidelines, for more convincing arguments and developments.
So what's so great, or bad, about plug-ins?
When it is all boiled down - and this is being a bit simplistic because there are variations on the theme - just one thing makes them different from ordinary hybrids (which have a major role to play too, let's not forget).
It is the plug-ins ability to hook up to the electric grid and soak its power for a few hours so you can cover up to 50km (I'll come back to that) on a low-cost, emissions free electric charge.
But when you stack that on top of the frugal engine-motor-battery combination we have come to expect from hybrids (such as the Toyota Prius) strange things start to happen.
Claimed fuel consumption reaches way into magical 100MPG-plus territory.
Emissions plunge to levels that - on paper - are substantially below the cleanest existing hybrid.
Performance goes through the roof because you get the combination of engine and electric motor power. And that transforms them into beasts when you put the foot down.
I've driven some of them. There are pros and cons. I've outlined most of the pros; here's a few cons.
Price is the biggest stumbling block. If it weren't for €7,500 or so in VRT rebate and SEAI grants for most of them, they would be madly out of reach. As it is they're pricey but manageable for a small number of enthusiasts - who can be 'green' and go-like-hell at the same time.
Of those I've driven I reckon you can, with a full charge and with no help from the engine, travel 25km to 35km. Most manufacturers claim 50km. I've never got within 15kms of it.
And it is hard to get into the habit of taking out the charging apparatus and plugging in every time.
But back to the positive.
If you commute say 50km/75km in total each day and don't drive too hard, and if you can charge up while at work, you might not have to use a drop of fuel all week. That's a perfectly feasible scenario.
Then off with you at the weekends. You'll still get your 35km 'pure electric drive' on top of the usually frugal hybrid combination of electric motor and engine. Most have an impressive range - anywhere from 750kms to upwards of 1,000km depending on size.
And if you get a chance you can let it rip on a decent bit of road (just stay under the speed limit, please).
The strange thing is that names we'd normally associate with posh and plush are among those pushing hardest on practicality.
I'm talking the likes of Mercedes, Porsche, Audi and BMW.
One of the best, more mainstream, exponents is the Mitsubishi Outlander PHEV sports utility and I think it is worthwhile dwelling momentarily on it as a way of demonstrating how PHEVs can work in the every day.
It has electric motors, batteries, a 2-litre petrol engine, emits just 44g/km, incurs €170 road tax and sips only 1.9litres every 100km (I stress that is the manufacturer's claim - it used a fair bit more when I drove it) and 824km range.
It also has an electric motor on each axle (powered by the bank of batteries) that drives the wheels - and that makes it a permanent four-wheel-drive SUV. The 2-litre petrol engine backs them up like a large charger or generator.
When the engine kicks in, it nearly always acts as a generator or charger. It feeds the batteries which power the electric motor.
But when you really want to whoosh, the engine kicks in to power the front wheels - and boy can it move.
More exotic is the Porsche Cayenne S e-hybrid. It uses just 3.4 litres every 100km and its emissions of 79g/100km are in line with those of the Toyota Prius. Their Panamera produces equally impressive figures.
And from BMW there is the i8 supercar plug-in hybrid. A handful have been bought here - not one suspects because owners want to scrimp on fuel but more for the daring design and approach to how we power our cars.
I've driven it here and in Scotland. Searing power but I'm not a fan of the up-and-over doors. And I've driven BMW's new X5 PHEV (they are poised with a whole line-up of such cars - including a 740e).
And when you see Mercedes making - and doing well with - a plug-in hybrid in their S-Class, you know there is something serious afoot. Again they expect to have a 10 plug-ins by 2017. That's roughly one every four months.
Prof Dr Thomas Weber, member of the Board of Management of Daimler AG and responsible for Group Research and Mercedes-Benz cars development sums up the genre rather well: "Plug-in hybrids are a key technology . . . they offer the best of both worlds; in the city (owners) can drive in all-electric mode, while on long journeys they benefit from the combustion engine's range."
Smaller and more affordable (€40,000 or so) is Audi's excellent A3 e-tron compact hatch. Its (claimed!) fuel consumption of 1.5litres per 100km is a staggering 188mpg and emissions are only 35g/km while it has a range of up to 940 kilometres.
We'll soon see its big, big brother PHEV the Q7 SUV e-tron quattro on our roads. It emits just 50g/km of C02 officially and averages a claimed 166.2mpg.
I keep using the word 'claimed' because real world conditions will knock the stuffing out of many figures but still leave them in the 'hugely-impressive' bracket. The Q7 uses a turbocharged 3-litre V6 common-rail diesel (254bhp) and an electric motor that develops 126bhp - pushing it to 100kmh in six seconds.
And Volvo's new Twin-Engine XC90 SUV makes a remarkable case. I've driven it too and was stunned as much by its audacious performance as its frugality.
Its T8 AWD 1,969cc petrol develops 320bhp and there is 80bhp from the electric motor. Road tax is just €170.
Contrast that with its expected-to-be-big seller diesel which does 48.7mpg compared with the plug-in's 104.8mpg. The diesel costs €390 in road tax; the plug-in €170. Work that out.
Also here now is Volvo's V60 Twin Engine diesel hybrid V60 (48g/km).
Volkswagen has really taken the PHEV concept to heart too with Golf and Passat GTEs both with extraordinarily low emissions.
The Passat's figures are remarkable: emissions of only 37g/km and a claimed 141mpg.
It is one of the best examples of a mainstream car going from using no fuel, to dawdling along normally to becoming a performance car when you press the special GTE button to fuse petrol and electric power.
Necessity is the mother of invention and plug-ins are certainly being pursued by automakers because of the relentless clampdown on emissions by legislators.
The numbers are small at the moment but as more are bought, and as technology improves, they should become more competitive - price is a major deterrent. Indeed many manufacturers are subventing cost to get numbers out there.
They know plug-ins offer only a partial solution to a burgeoning transport emission problem worldwide.
How much of a solution depends on so many variables.
The main one is: how long are automakers prepared to back this horse called PHEV? Those I've spoken to all say they need the lower emissions from PHEVs to get down their overall average in the face of heavy fines if they fail to.
So the dice is loaded. PHEVs are here to stay for quite a while it seems.
We now just need to acquire the discipline of everyday use to extract as much of their cheap-motoring ability as possible.