Compare aerodynmics of two cars

In summary, the Mercedes CLA has a lower Cd of 0.22 compared to the CLS C218's Cd of 0.26. This is due to the CLA having a more aerodynamic body shape and additional aero features. However, if we were to modify the CLS C218 by using narrow tires and a flat bottom, it could potentially have a better Cd than the CLA. The CLS also has a larger frontal footprint area and more drag caused by skin friction, which would still result in it using more fuel even with a lower Cd.
  • #1
Jurgen M
Mercedes CLA has Cd =0.22(180 Blue Efficiency) and Cd=0.23(180).
CLS C218 has 0.26, but CLS has wide tires, no flat bottom and other aero features like CLA.

aero features of CLA:
https://www.car-engineer.com/mercedes-cla-is-the-most-aerodynamic-production-car-of-the-world/

If we compare just body shape ,do you think CLS has better Cd from CLA, for example if we put narrow tires, flat bottom etc maybe CLS will have even better Cd then CLA?

I ask this because CLA is short, rear roofline looks to stubby, rear window+trunk slope is too steep,this can cause flow separation or too steep slope induce low pressure at rear window+trunk.

CLS is longer, more streamlined siluetthe,rear end slope is not so steep.

all-building-facade-moscow-russia-august-232195598.jpg
mercedes-benz-cla-c117-45-amg-2013-379557.jpg
 
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  • #2
Jurgen M said:
...
If we compare just body shape ,do you think CLS has better Cd from CLA, for example if we put narrow tires, flat bottom etc maybe CLS will have even better Cd then CLA?

I ask this because CLA is short, rear roofline looks to stubby, rear window+trunk slope is too steep,this can cause flow separation or too steep slope induce low pressure at rear window+trunk.

CLS is longer, more streamlined siluetthe,rear end slope is not so steep.
Modifying the CLS C218 car, you could reduce the factory's Cd.

1) The CLS has wide tires because it weights around 1950 kgf, compared to the 1540 kgf of the CA.
2) It also has a frontal footprint area about 4% bigger than the CA.
3) Being longer, it has more drag caused only by skin friction.

Because those three factors mentioned above only, it will still use more fuel after you improve its Cd to match the CA's Cd of 0.22.
 
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  • #3
Lnewqban said:
Modifying the CLS C218 car, you could reduce the factory's Cd.

1) The CLS has wide tires because it weights around 1950 kgf, compared to the 1540 kgf of the CA.
2) It also has a frontal footprint area about 4% bigger than the CA.
3) Being longer, it has more drag caused only by skin friction.

Because those three factors mentioned above only, it will still use more fuel after you improve its Cd to match the CA's Cd of 0.22.
I mean if we compare only car body, which will have better Cd..
 
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1. What is aerodynamics?

Aerodynamics is the study of how air moves around objects, such as cars, and how it affects their performance and efficiency.

2. How do aerodynamics affect a car's performance?

Aerodynamics can greatly impact a car's performance by affecting its speed, acceleration, handling, and fuel efficiency. A car with better aerodynamics will experience less drag and therefore be able to move more efficiently through the air.

3. How are aerodynamics measured in cars?

Aerodynamics in cars are measured using various factors such as drag coefficient, downforce, and lift. These measurements can be obtained through wind tunnel testing and computer simulations.

4. What are some ways to improve a car's aerodynamics?

Some ways to improve a car's aerodynamics include reducing its frontal area, smoothing out its body shape, adding aerodynamic features such as spoilers and diffusers, and minimizing gaps and openings that can cause drag.

5. How can I compare the aerodynamics of two cars?

To compare the aerodynamics of two cars, you can look at their drag coefficients, downforce and lift measurements, and other aerodynamic features. You can also compare their performance in wind tunnel testing or through computer simulations.

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