Tuesday 17 January, 2012. The Green Piece Column.
I have a confession to make. Even after four and a half years of working for TheGreenCarWebsite.co.uk, car makers still manage to occasionally confuse me with the wealth of terminology they use to describe their low emission models.
With this year expected to be a ‘year for the hybrid’ with many new hybrids, plug-in hybrids and range-extended cars to arrive in 2012- including a number from car makers who are venturing into this market for the first time- we thought it was about time we clarified once and for all the difference is between a typical hybrid model and a range-extended car. And in case you wondered some car maker’s claim to make ‘proper’ hybrids and others describe their cars as ‘mild hybrids’, we’ll clear that up too.
A ‘hybrid’ car is simply a car which is powered by two different power sources, so it could technically refer to almost any dual-fuel car. But for the purpose of this column, we’re going to look at the combustion engine/electric hybrid, with a breakdown of the most important terms you might hear.
Hybrid types and terminology
- Micro-hybrid: Is simply a car which uses a start-stop function. Many of the cars we talk about now use a stop-start function, which switches off the engine when the car is stationary and automatically restarts it when the clutch is pressed down and a gear is selected. They are not really proper hybrids and as such as usually just advertised as including start-stop technology.
- Series hybrid: is also known as a Range-Extended car. In this set up, the engine never directly drives the wheels. Instead the engine turns a generator which can then either charge the battery or power the electric motor which then drives the wheels. At low speeds and for a limited range, the batteries can power the electric motor instead and thus drive the wheels. Series hybrids are particularly efficient in city driving because you avoid the switch from electric power to mechanical driving. Range-extended cars such as the Chevrolet Volt and Vauxhall Ampera can also be recharged from the mains electricity, and in this sense, they are similar to Plug-in Hybrids.
- Parallel hybrids – In this set-up both the engine and the electric motor can power the transmission. Because both sources of power can turn the wheels, you can maximize performance and economy. Compared to the Series or Range-extended car, the Parallel hybrid is particularly efficient in highway driving when a combustion engine can maximize its mpg while the small battery pack is unable to provide enough power on its own.
- Power-split hybrid or series-parallel hybrid: is another type of parallel hybrid but also include a power split device which allows the car to capitalize on the ability of an electric powertrain’s ability to supply full torque capability from a standstill. By using the electric motor from low speeds, this enables the car maker to use a smaller, less powerful combustion engine without leaving the car feeling underpowered and lacking in acceleration. Cars such as the famous Toyota Prius are series-parallel hybrids.
- Diesel hybrids- Could potentially work like with any of the powertrain arrangements we’ve seen used for petrol-hybrids. Diesel hybrids have long been talked about as a good way to truly maximize the fuel economy of the hybrid car. At last, such models are coming to the market, with both the Volvo V60 Plug-in Hybrid and the Peugeot 3008 Hybrid4 arriving in the UK this year. The Peugeot car uses a series-parallel set-up while the Volvo is also a Plug-in Hybrid.
- Plug-in Hybrid electric vehicles (PHEVs) – A hybrid with a battery pack that can be recharged to allow it to make greater use of electric driving ability. In 2012, we will see the launch of two such cars; the Toyota Prius Plug-in and the Volvo V60 Plug-in hybrid. They take consumers a step closer to fully electric vehicles but without compromising range or performance.
2012 hybrids and range-extended cars to come:
So now you’re clear on the technologies, but just why is 2012 to be an exciting year in the hybrid/range-extended field?
Here’s a list of the model which will launch here in the UK in 2012:
BMW ActiveHybrid 5 goes on sale in UK from early this year and will be rated as emitting 149g/km CO2. Using a 3.0 litre engine with an electric drive system, the car is capable of powering up to a top speed of 37mph on electricity alone. Read more.
Chevrolet Volt like the Vauxhall Ampera will arrive on UK roads from early this year. Sharing drivetrain technology with the Ampera, this range-extended model avoids the ‘range-anxiety’ of fully electric cars by offering a driving range of as much as 360 miles using its battery power and petrol engine. Read more.
Citroen DS5 Hybrid4 will launch alongside non-hybrid DS5 models this March, and will offer emissions of just 99g/km CO2. It use the same Hybrid4 diesel hybrid technology as featured in the Peugeot car below. Read more.
Peugeot 3008 Hybrid4 has already begun making delivers so expect to see them on the road now. It comes equipped with a 2.0-litre HDi engine, driving the front wheels and a 37bhp electric motor driving the rear wheels. Emissions are rated at just 109g/km and fuel economy at 67.2mpg. Despite this, there is 200bhp and maximum torque of 450 Nm. Read more.
Toyota Prius Plug-in will begin making deliveries from early summer in the UK. Using a high capacity lithium-ion battery, it has an electric-only range of around 14 miles. If that is not enough then you can recharge the car via a standard 240V electricity supply in just an hour-and-a-half. Official figures are 49g/km and 134mpg combined cycle. Read more.
Toyota Yaris hybrid will use the familiar Hybrid Synergy Drive (HSD) technology that Toyota already uses on its Prius and Auris hybrid models, only on a more compact scale. It is expected to arrive in the UK in early summer. Read more.
Vauxhall Ampera will arrive in UK showrooms from May and is available to order now. Using a 16 kWh lithium ion battery to power a 111kW/150PS electric motor, the car can achieve a distance of between 25 and 50 miles on electricity alone while a 1.4 litre petrol engine extends the car’s total driving range to 360 miles. Read more.
Volvo V60 Plug-in Hybrid is both a plug-in hybrid and a diesel hybrid and is expected to be given an mpg rating of around 134mpg with an emissions rating of around 45g/km CO2. Being dubbed as ‘three cars in one’ the sports wagon model will arrive in the UK this November. Read more
Faye Sunderland.
