TEN SECOND REVIEW
The Audi A3 e-tron plug-in hybrid makes some interesting numbers. It's claimed to return 188mpg, emit 35g/km of CO2 and get to 62mph in just 7.6 seconds. Real world economy is around a third of this number, which makes the asking price look somewhat optimistic.
Hybrid cars have a problem and it's all about efficiency. The basic issue is this. If you want to recharge the batteries on your hybrid, as you will need to do each time you drive it, you're relying on the relatively primitive concept of suck, squeeze, bang and blow of your internal combustion engine.
As any physicist will tell you, such engines tend to have an efficiency of between 18 and 20 per cent. In other words you wouldn't design a power station around one.
The average efficiency of an average electric motor is around 85 per cent. So the key to making the electric aspect of a hybrid car cost-effective is not to use the expensive and inefficient petrol motor to charge the batteries.
Plug the car into a mains outlet and let a power station do the job instead. Audi certainly thinks so in any case, which is why it claims its A3 e-tron plug-in hybrid will manage 188mpg.
The A3 e-tron is powered by a 148bhp 1.4 litre TSI petrol engine and a 99bhp electric motor that's tucked between the gearbox and power unit, driving front wheels. Rather cleverly, Audi has designed the electric motor to replace a conventional starter motor.
Power is then directed through a six-speed sequential twin-clutch transmission which is quick-witted enough to handle the rapid spooling of the electric motor.
There's actually another clutch in this adapted gearbox which allows the motors to decouple, permitting the car to coast with less friction which, Audi claims, is a more efficient than trying to scavenge energy back through recuperation.
The result of this is a car that defaults to electric power on start up and will drive up to 31miles on electric power alone.
It'll even motorway cruise at speeds of up to 80mph on batteries, although not for too long.
The petrol engine can instantly be engaged by either kickdown or by toggling a switch from pure EV to hybrid mode.
With both power sources operating, the e-tron will step smartly off the line, getting to 62mph in 7.6 seconds and running onto a top speed of 138mph.
Handling is excellent, helped by a lower centre of gravity than the standard A3 and better weight distribution too, thanks to a light engine and the repositioning of the fuel tank.
Design and Build
The e-tron is offered in the larger five-door A3 Sportback body and doesn't look a whole lot different to any other Sportback. There's some subtle badging at the back and the charging point is typically Audi-slick. You slide the four-ringed grille badge to the side and that reveals a socket that plugs into your wall with a supplied lead.
Audi has done quite a bit of fairly fundamental shifting under the skin though.
The fuel tank has been moved to the rear of the car, now sitting beneath the boot floor, while the 8.8kWh, 125kg battery resides under the rear seat. Total boot space drops by 100-litres to 280-litres as a result, which is just about the only practical caveat here.
Otherwise it's largely business as usual. At 4,310mm long, this A3 Sportback body is only 178mm shorter than the original A4 Avant but the wheelbase is actually longer, making it feel more spacious inside for both driver and passengers.
That wheelbase has increased by 58mm compared to its predecessor, and it's 35mm longer between the axles than the three-door version. The interior features a dial pack that includes the car's range, with bar graphs showing how far you'll travel on petrol and electric power. You can also choose an energy flow schematic.
Audi have even swapped out the conventional heater and air con systems for low-energy consumption electric units.
Market and Model
The big issue for most buyers is whether they see the A3 e-tron's almost £33,000 asking price as being justifiable when a 2.0 TDI 184 diesel model will typically cost around £8,000 less. That nine grand would buy you about 65,000 miles worth of diesel.
Even if you drove the A3 e-tron purely on electric power for 31 miles a day, every day for three years on your work commute, you'd only cover around 23,000 miles. In terms of pure hard-headed finance, it's going to find it hard to justify sales against a diesel; in the short to medium term at least.
The interior is familiar fare to anybody who speaks fluent Audi design language, with a typically spare look for the interior, with four circular air vents punctuating the dash and a 7in sat-nav screen that emerges from the top.
This is controlled by the latest generation of MMI dial, with a very clever feature. The touchpad that first appeared on the A8 is now integrated into the top of the rotary controller.
Cost of Ownership
The stated fuel consumption figure of 188mpg is somewhat questionable given that if you put a gallon of fuel in this A3 e-tron and coupled that with a fully-charged battery, you'd probably sputter to a halt after about 80 miles or so.
Think of it as a quirk of the European testing system that Audi has managed to exploit.
The fuel tank in this car is a 40 rather than a 50-litre unit, so with both electric and petrol combined, your total range is 584 miles.
On a good day, that equates to about 66mpg, so not really any better than the extra urban economy of a good diesel and with less range to boot. It's hard to argue with the 35g/km CO2 emissions figure if you're the person tasked with taxing it though. And there are big potential savings to be made in company car tax.
Depreciation is a tough one to assess. Who's going to buy the A3 e-tron? It's certainly not going to appeal to business users looking to minimise their pence per mile figures; it just doesn't compete against a diesel in that regard.
Private buyers will probably be similarly reluctant to make a big upfront commitment for a car with an uncertain payoff period and a more involved recharging process.
The battery will charge in three hours and forty-five minutes on a household socket, which is relatively brisk.
Although the headline numbers of 188mpg, 35g/km of CO2 and a 0-62mph time of just 7.6 seconds make the Audi A3 e-tron appear an instant game-changer, look behind the numbers and you'll find things not quite so clear cut.
In fact, a counter perspective might well be that you're paying around £8,000 over the top of an A3 Sportback 184PS diesel and getting a car that's slower, drinks more fuel, carries less luggage and offers inferior touring range.
Of course, the e-tron has other benefits. It can run in a pure EV mode, it offers better weight distribution and it feels a far more special piece of kit than a diesel hatch. Can you put a price on that?
You can perhaps if you measure the savings you'll make in company car tax. And this model certainly scores as a car you can drive as an EV on short commutes to work, but which is capable of long weekend trips. As a technical showpiece, it's an intriguing thing. As a sales proposition though, you might need to scour the small print quite carefully.