Home CitroŽnŽt home

Site search powered by FreeFind
Do NOT include 'Citroen' in your search terms

CitroŽn at the 2007 Internationale

Automobil-Ausstellung in Frankfurt


A new environmental model

CitroŽn is launching the C4 BioFlex in September 2007. The C4 BioFlex is a flexfuel vehicle using regular fuel and ethanol. It will be launched first in France and Sweden, and soon after in other European countries. Most of these countries have attractive policies for these new fuel types. 

The C4 BioFlex is the Marque’s first flexfuel vehicle in Europe. CitroŽn already sells flexfuel cars in Brazil, where this kind of vehicle accounted for 65% of the brand’s sales in 2006, and more than 80% since the start of 2007. With this offering, CitroŽn is present on a new market in this world region. E85 fuel pumps are beginning to appear in France. Some 500 pumps are expected to be up and running by the end of the year. 

Fitted with a 1.6-litre engine generating 82 kW, the C4 BioFlex benefits from all the equipment on offer in the C4 range, with the same trim levels.

It contributes to greenhouse gas reduction by cutting CO2 emissions by 5% over a combined cycle and also reduces fossil-fuel dependency by using renewable energy.

From field to wheel, emissions are reduced by up to 40%. 

Available as a 5-door hatchback, the C4 BioFlex ships at the same price as the petrol 1.6i 16V models, at €18,650 for the Pack version, €20,000 for Ambiance, and €22,150 for the Exclusive model. 

C4 BioFlex: an excellent environmental scorecard

Bioethanol is an alcohol produced by fermentation of sugar from plants such as beetroot or starch from cereals  such as wheat and corn.

The use of bioethanol has several environmental advantages: 

  • Unlike fossil fuels, the greenhouse gas emissions (CO2) produced by cars running on biofuels are to a large extent absorbed by the growth of plants used to produce bioethanol. This process of absorption also concerns the CO2 emitted by other sources. From field to wheel, emissions are reduced by up to 40%.
  • Because this type of biofuel contains oxygen, it also helps reduce other pollutants.  E85 fuel is also sulphur-free.
  • Lastly, unlike fossil fuels, biofuels are renewable energies.
The C4 BioFlex thus initiates a virtuous cycle of reducing and absorbing greenhouse gas emissions.

C4 BioFlex: an impressive economic scorecard

The economic scorecard of biofuel vehicles varies according to country and tax policy. 

At about €0.80 per litre, current E85 prices in France make the C4 BioFlex particularly competitive. 

In addition, biofuel use is encouraged by certain tax systems: 

  • 50% or total exemption – depending on the region – from the pro-rata tax on car registration fees,
  • Exemption from the tax on company vehicles for 2 years,
  • Exceptional amortisation of company cars over a period of 12 months, instead of 5 years,
  • 80% recovery of VAT on fuel.

E85 is already widely used in Sweden. The country has 650 E85 fuel pumps and more than 13% of vehicles sold in 2006 were Flexfuel models.

Numerous fiscal incentives (tax, tolls and parking) favour the use of biofuel.

Over a combined cycle, the C4 BioFlex consumes 9.8 l/100 km and emits 160 g of CO2 per km, compared with 7.1 l/100 km and 169 g of CO2 per km for the standard 1.6i 16V model.

Although the C4 BioFlex consumes more fuel, it is considerably cheaper to run. In France, it costs 7.84 euro cents per kilometre, with E85 fuel at €0.80 a litre, compared with the conventional model’s 9.23 euro cents per kilometre, with SP95 petrol at €1.30 a litre. 

C4 BioFlex: technological advance for real results

The C4 BioFlex powertrain was designed and developed to run on normal unleaded fuel (RON 95 or 98), on bioethanol with up to 85% ethanol content (E85), and on a mix of the two containing between 0 and 85% ethanol. 

Developing the C4 BioFlex required work in two key areas. First, all components and parts had to tolerate contact with ethanol. Second, the engine had to function optimally regardless of the proportion of alcohol in the fuel. 

Imported from Brazil, the engine features several modifications already applied to engines used locally, mainly concerning parts that come into contact with the fuel, such as rings and valve seats. 

Changes were also made to the fuel circulation system, involving the tank, fuel gauge and pump module, pipes and fuel filter. 

Finally, the engine software has been adapted to include new settings that adjust automatically to the alcohol content in the fuel. Each time the tank is filled, an analysis is made of alcohol content in order to select the best operating curve. During the analysis, the engine functions with “protection” settings compatible with all authorised fuel blends containing between 0 and 85% ethanol content. 

Performance has been boosted in E85 mode, with maximum power of 82 kW (or 113 bhp DIN, compared with 80 kW/110 bhp DIN) still at 5,800 rpm – for a 2.5% improvement – and maximum engine torque of 153 Nm (up from 147 Nm), still at 4,000 rpm, for a 4% improvement. 

Running on standard unleaded fuel (SP95), the engine performs practically identically to the 1.6i 16V version. 

The adaptation is completely transparent for the customer, apart from the maintenance plan, with services every 20,000 km for the French market.


C4 1.6i 16V BioFlex


Unleaded 95 RON - Superethanol E85


5 speed

French fiscal rating



SP 95 (E0)

Superethanol (E85)

Pollution standard

Euro IV

Euro IV




Cylinders - valves

4 - 16

4 - 16

Bore - stroke (mm)

78.5 - 82

78.5 - 82

Capacity (cm3)



Compression ratio

11 to 1

11 to 1

Max power EEC:kW-rpm

80 - 5800

82 - 5800

Max power DIN: bhp-rpm

110 - 5800

113 - 5800

Max torque EEC:Nm-rpm

147 - 4000

153 - 4000




205 / 55 R16 or 205 / 50 R 17


Variable assistance

Steering ratio

16 to 1

Turns lock to lock


Steering wheel diameter (mm)


Turning circle: kerbs - walls (m)

10.7 - 11.3



Front axle

Pseudo McPherson

Rear axle

Flexible transverse beam






Front: diameter / disc thickness / calliper type

Ventilated 266/22/Floating (283x26 with ESP)

Rear: diameter / disc thickness / calliper type

249 / 9/Floating



Length - Width (mm)

4260 - 1773

Height - Wheelbase (mm)

1458 - 2608

Track: FR (mm)


Track: R (mm)


Cabin length (mm)


Elbow room front-rear (mm)

1442 - 1432

Boot length-width (mm)

802 - 1034

Boot volume VDA: top of rear seat back (dm3)


Boot volume VDA: under parcel shelf (dm3)


Boot volume VDA: under ceiling, seats folded (dm3)




Fuel tank (litres)






A (m≤) - CdA (m≤)



SP 95 (E0)

Superethanol (E85)

Top speed (km/h)



400 m standing start (s) /



1000 m standing start (s) / driver alone



0 to 100 km/h (s) /




SP 95 (E0)

Superethanol (E85)

Urban (l/100 km)



Extra-urban (l/100 km)



Combined (l/100 km)



CO2 (g/km)



CO2 (g/km) field to wheel


Lower than 100 g

© 2007 Julian Marsh/CitroŽnŽt + SA Automobiles CitroŽn