According to reports Audi originally heard that Renault were building a 3 ltr car. Audi were concerned that Renault may steal the eco lime light. Some time later Audi realised that that they didnt need to worry, they were thinking on very different lines
Renault 3ltr V6 Clio
Audi A2 1.2TDI 3Ltr/100km. (2.99 Ltr/100km to be exact)
Progress from the wind tunnel
Audi's engineers have reduced the drag coefficient of the A2 1.2 TDI to a sensationally low cD = 0.25 - making the three-litre version the most aerodynamically efficient of any production passenger car. As when optimizing the weight, this achievement can be expressed as a clear-cut equation: excellent basis + fine-tuning of detail features = Advancement Through Technology.
The body shape of the Audi A2 is characterized by lines tapering to the rear, and is thus reminiscent of one of the most aerodynamically effective shapes, the droplet. The generous amount of space for rear passengers comes as something of a surprise when one considers how sleek the car's exterior is. This is all thanks to a further highlight of the A2 body, the Space Floor Concept. The rear footwells are sunk into the floor and therefore 13 centimetres lower than the front footwells; this allows rear passengers to find an ergonomically good, relaxed seated position, making the rear seats superior even to many a larger, nominally more spacious car.
For the Audi A2 owner this is a good thing, additional parts that were intended to make the 4 seater slip through the air are available to retro fit to your A2 (sort of). A German forum member as been creating various mods to make the underside of the A2 cut through the air to increase fuel economy. as well as retro fittng the 1.2 Aero mods from Audi
As a percentage of the total drag coefficient of 0.29 (this is a very good drag coefficient but the A2 is even better!) the various elements that make up this drag are:
Cooling package (including radiator, intercooler, oil cooler, etc) 33.4%
Exterior 31.7%
Front wheels 13.1%
Rear wheels 6.9%
Floor 6.9%
Rear Axle 3.1%
Engine 3.1%
Front Suspension 1.4%
Exhaust 0.7%
Lowering the vehicle by 30mm approx. -5
Smooth wheel covers -1 to -3
Wide tires +2 to +4
Windows flush with exterior approx. -1
Sealing body gaps -2 to -5
Underbody panels -1 to -7
Concealed headlamps +3 to +10
Outside rearview mirrors +2 to +5
Airflow into the enginecompartment +4 to +14
Brake cooling devices +2 to +5
Interior ventilation approx. +1
Open windows approx. +5
Open sunroof approx. +2
Roof-mounted surfboard rack approx. +40
In the last 10 years we have been producing style over function, which is something most are prepared to trade for the looks. However 30% of your engine power is used to push you car through the air, make your car slippery in the air and you will see results
2.10 - A smooth brick
0.90 - A typical bicycle plus cyclist
0.70 - A Formula 1 car (avg according to track)
0.70 - Caterham Seven
0.60 - A typical pick up truck
0.57 - Hummer H2, 2003
0.51 - Citron 2CV
0.42 - Lamborghini Countach, 1974
0.39 - Dodge Durango, 2004
0.38 - Volkswagen Beetle
0.38 - Mazda Miata, 1989
0.37 - Clio V6 3ltr
0.37 - Ferrari F50, 1996
0.36 - Citron DS, 1955
0.36 - Ferrari Testarossa, 1986
0.36 - Opel GT, 1969
0.36 - Citron CX, 1974
0.35 - BMW Mini
0.34 - Ford Sierra, 1982
0.34 - Audi TT Mk1
0.34 - Ferrari F40, 1987
0.34 - Chevrolet Caprice, 1996
0.33 - Chevrolet Camaro, 1995
0.33 - Dodge Charger, 2006
0.33 - Audi A3, 2006
0.33 - Subaru Impreza WRX STi, 2004
0.32 - Toyota Celica, 2005
0.32 - Ford Focus 1998
0.31 - Audi A3 2003
0.31 - Citron GSA, 1980
0.30 - Saab 92, 1947
0.30 - Audi 100, 1983
0.30 - Audi TT Mk2 (with a wider and larger frontal area)
0.30 - Porsche 996, 1997
0.29 - Honda CRX HF 1988
0.29 - Subaru XT, 1985
0.29 - BMW 8 Series, 1989
0.29 - Porsche Boxster, 2005
0.29 - Chevrolet Corvette, 2005
0.29 - Honda Accord Hybrid, 2005
0.29 - Lotus Elite, 1958
0.28 - Porsche 997, 2004
0.28 Audi A2 (not 1.2 model)
0.27 - Infiniti G35, 2002 (0.26 with "aero package")
0.27 - Mercedes-Benz W203 C-Class Sedan, 2001 - 2007
0.26 - Toyota Prius, 2004
0.25 - Honda Insight, 1999
0.25 Audi A2 1.2 model
0.19 - Mercedes-Benz "Bionic Car" Concept, 2005
0.137 - Ford Probe V prototype, 1985
0.15 - Volkswagen ARVW
0.06 - The boxfish
0.04 - A drop of water
I decided to fit these 1.2 aero modifications to my car after suggestions from a German A2 owner as they are applicable to the A2 1.2 TDI designed to cut through the air with a low drag coefficient. I have also decided to fit wheel deflectors to the rear wheels to reduce wake and drag. (pics to follow)
Further aero improvements to come... i know, i know
Information taken from articles relating to improving Aero dynamics.
http://autospeed.com/cms/A_2455/article.html
http://autospeed.com/cms/A_2456/article.html
http://autospeed.com/cms/A_108676/article.html
http://autospeed.com/cms/A_108677/article.html?popularArticle
http://autospeed.com/cms/A_109778/article.html?popularArticle
Renault 3ltr V6 Clio
Audi A2 1.2TDI 3Ltr/100km. (2.99 Ltr/100km to be exact)
Progress from the wind tunnel
Audi's engineers have reduced the drag coefficient of the A2 1.2 TDI to a sensationally low cD = 0.25 - making the three-litre version the most aerodynamically efficient of any production passenger car. As when optimizing the weight, this achievement can be expressed as a clear-cut equation: excellent basis + fine-tuning of detail features = Advancement Through Technology.
The body shape of the Audi A2 is characterized by lines tapering to the rear, and is thus reminiscent of one of the most aerodynamically effective shapes, the droplet. The generous amount of space for rear passengers comes as something of a surprise when one considers how sleek the car's exterior is. This is all thanks to a further highlight of the A2 body, the Space Floor Concept. The rear footwells are sunk into the floor and therefore 13 centimetres lower than the front footwells; this allows rear passengers to find an ergonomically good, relaxed seated position, making the rear seats superior even to many a larger, nominally more spacious car.
For the Audi A2 owner this is a good thing, additional parts that were intended to make the 4 seater slip through the air are available to retro fit to your A2 (sort of). A German forum member as been creating various mods to make the underside of the A2 cut through the air to increase fuel economy. as well as retro fittng the 1.2 Aero mods from Audi
As a percentage of the total drag coefficient of 0.29 (this is a very good drag coefficient but the A2 is even better!) the various elements that make up this drag are:
Parts Percentage of Total Drag
Cooling package (including radiator, intercooler, oil cooler, etc) 33.4%
Exterior 31.7%
Front wheels 13.1%
Rear wheels 6.9%
Floor 6.9%
Rear Axle 3.1%
Engine 3.1%
Front Suspension 1.4%
Exhaust 0.7%
Modification % Change
Lowering the vehicle by 30mm approx. -5
Smooth wheel covers -1 to -3
Wide tires +2 to +4
Windows flush with exterior approx. -1
Sealing body gaps -2 to -5
Underbody panels -1 to -7
Concealed headlamps +3 to +10
Outside rearview mirrors +2 to +5
Airflow into the enginecompartment +4 to +14
Brake cooling devices +2 to +5
Interior ventilation approx. +1
Open windows approx. +5
Open sunroof approx. +2
Roof-mounted surfboard rack approx. +40
In the last 10 years we have been producing style over function, which is something most are prepared to trade for the looks. However 30% of your engine power is used to push you car through the air, make your car slippery in the air and you will see results
2.10 - A smooth brick
0.90 - A typical bicycle plus cyclist
0.70 - A Formula 1 car (avg according to track)
0.70 - Caterham Seven
0.60 - A typical pick up truck
0.57 - Hummer H2, 2003
0.51 - Citron 2CV
0.42 - Lamborghini Countach, 1974
0.39 - Dodge Durango, 2004
0.38 - Volkswagen Beetle
0.38 - Mazda Miata, 1989
0.37 - Clio V6 3ltr
0.37 - Ferrari F50, 1996
0.36 - Citron DS, 1955
0.36 - Ferrari Testarossa, 1986
0.36 - Opel GT, 1969
0.36 - Citron CX, 1974
0.35 - BMW Mini
0.34 - Ford Sierra, 1982
0.34 - Audi TT Mk1
0.34 - Ferrari F40, 1987
0.34 - Chevrolet Caprice, 1996
0.33 - Chevrolet Camaro, 1995
0.33 - Dodge Charger, 2006
0.33 - Audi A3, 2006
0.33 - Subaru Impreza WRX STi, 2004
0.32 - Toyota Celica, 2005
0.32 - Ford Focus 1998
0.31 - Audi A3 2003
0.31 - Citron GSA, 1980
0.30 - Saab 92, 1947
0.30 - Audi 100, 1983
0.30 - Audi TT Mk2 (with a wider and larger frontal area)
0.30 - Porsche 996, 1997
0.29 - Honda CRX HF 1988
0.29 - Subaru XT, 1985
0.29 - BMW 8 Series, 1989
0.29 - Porsche Boxster, 2005
0.29 - Chevrolet Corvette, 2005
0.29 - Honda Accord Hybrid, 2005
0.29 - Lotus Elite, 1958
0.28 - Porsche 997, 2004
0.28 Audi A2 (not 1.2 model)
0.27 - Infiniti G35, 2002 (0.26 with "aero package")
0.27 - Mercedes-Benz W203 C-Class Sedan, 2001 - 2007
0.26 - Toyota Prius, 2004
0.25 - Honda Insight, 1999
0.25 Audi A2 1.2 model
0.19 - Mercedes-Benz "Bionic Car" Concept, 2005
0.137 - Ford Probe V prototype, 1985
0.15 - Volkswagen ARVW
0.06 - The boxfish
0.04 - A drop of water
I decided to fit these 1.2 aero modifications to my car after suggestions from a German A2 owner as they are applicable to the A2 1.2 TDI designed to cut through the air with a low drag coefficient. I have also decided to fit wheel deflectors to the rear wheels to reduce wake and drag. (pics to follow)
Further aero improvements to come... i know, i know
Information taken from articles relating to improving Aero dynamics.
http://autospeed.com/cms/A_2455/article.html
http://autospeed.com/cms/A_2456/article.html
http://autospeed.com/cms/A_108676/article.html
http://autospeed.com/cms/A_108677/article.html?popularArticle
http://autospeed.com/cms/A_109778/article.html?popularArticle