- #1
sc2dave
do front air dams help to increase gas mileage a bit?
sc2dave said:do front air dams help to increase gas mileage a bit?
Nenad said:Air resistance is proportional to velocity squared. Therefore, if you drive at speeds of about over 100miles/hour, then aerodynamics takes on an effect in a cars preformance and gas mileage, but at lower speeds, the effect is neglegable.
Stingray said:Where did 100 mph come from? Drag actually does have a significant impact on fuel consumption at regular highway speeds (~70 mph). Total drag might consume up to ~20 hp at that speed, which is significant.
Stingray said:Clausius,
While I agree with your calculation, I postulated 70 mph=110 kph, which is actually fairly low for most American highways (despite being above most speed limits). Also, cars popular here tend to be a bit bigger than 1.5 m^2. 20 hp is not unreasonable for a sedan if the parameters are changed slightly.
Well, this is your personal opinion. I don't think so. I don't think that Ford thought too much in aerodynamics when designing the Ford Focus. On the other hand, i do think that Ferrari thinks of aerodynamics indeed. But the purposes of both cars are different.Stingray said:Your claim about 8% losses is completely incorrect, though. At your estimate of 9 hp lost to drag, that would imply that it requires 110 hp to go 100 kph, which it clearly does not. Manufacturers do worry a lot about aerodynamics. Even the horribly underpowered Prius and Insight have highly optimized shapes. Cars haven't been designed on looks (and packaging) alone for more than 20 years now.
Clausius2 said:Well, if you want to change the parameters, I will change the whole formula, because it is completely innacurate. The [tex]C_x[/tex] factor is a rough simplification of the car's aerodynamic. It is based on averaged experimental results, on how it is measured the coefficient. Also, it is false that the aerodynamic drag is proportional to the square of the speed.
Well, this is your personal opinion. I don't think so. I don't think that Ford thought too much in aerodynamics when designing the Ford Focus. On the other hand, i do think that Ferrari thinks of aerodynamics indeed. But the purposes of both cars are different.
Also, i didn't understand what you meant in your edit.
How can you prove that?Stingray said:Also, the Ford Focus has a better drag coefficient than any Ferrari (but they're more concerned with lift than drag).
Stop writting about aerodynamics. This statement proves you have NO IDEA of what are you talking about. I am not going to say anything more, because you have disqualified yourself in this stuff.Stingray said:Drag can be split up into two parts. One is roughly independent of the object's length (in the direction of the flow), while the other is not. This latter effect is directly due to viscosity, and as I remember, it is ~10% of the total drag in most cases.
Clausius2 said:How can you prove that?
Stop writting about aerodynamics. This statement proves you have NO IDEA of what are you talking about. I am not going to say anything more, because you have disqualified yourself in this stuff.
Cliff_J said:Clausius2 - normally you have very informative posts but I do believe you have a mistake or poorly phrased statement above. If 9HP is the aero drag estimate and this is 8% of the overall friction then the overall losses would be 112.5HP at 100KpH, a very high number. Did you happen to intend to say 80% of the overall friction, for a total of 11.25HP at 100KpH, a more reasonalbe sounding figure?
They really should be stating at what Reynolds number those Cd's are calculated at. Without some kind of reference, the number is not quite meaningless, but leaves a lot open to question. Chances are it's not an apples-to-apples comparisonStingray said:Manufacturers usually give their cars' specifications. Play with google a bit, and you'll get that the Focus has a drag coefficient of 0.32. The 360, F430, 550, and 575M Coupes are 0.33 (convertibles are higher). The Enzo is 0.36. You can look up older models if you want, but I doubt you'll find anything lower. I can give specific links if you want.
FredGarvin said:They really should be stating at what Reynolds number those Cd's are calculated at. Without some kind of reference, the number is not quite meaningless, but leaves a lot open to question. Chances are it's not an apples-to-apples comparison
Clausius2 said:No I didn't mean anything of what you said. I meant an 8% of the TOTAL available engine power is lost in aerodynamic drag at 100km/h. I could have said an 8.1%, an 8.5%, a 10%, but never a 20%, a 30% or so, which I think they do are very high numbers.
Andy said:If the cars drag coeffecient is high would that also lead to a high downforce?
Andy said:If the cars drag coeffecient is high would that also lead to a high downforce?
edward said:To simplify the original topic, the purpose of an airdam is to improve the aerodynamics of a vehicle by not allowing the airflow to pass under the vehicle. The underside of most vehicles is an aerodynamic nightmare.
At Nascar speeds cars will actually go airborne if the front end of the vehicle is lifted or if the airdam is torn off.
Does an airdam improve gas mileage? One would probably help some at 75mph on the interstate highways. For most practical purposes in everyday driving they don't help much. And since they are located so close to the ground that they are easily broken.
sc2dave said:so,a spoiler should help at least a little bit,then,right?
A front air dam, also known as a front spoiler, is a small, aerodynamic panel located at the bottom of the front bumper of a car. Its primary function is to reduce drag and improve the car's overall aerodynamics, which can lead to better fuel efficiency and higher mileage.
Yes, adding a front air dam can improve a car's mileage. By reducing drag, the car experiences less resistance as it moves through the air, which in turn requires less energy and fuel to maintain its speed.
In addition to improving mileage, a front air dam can also help improve stability at high speeds and reduce the amount of dirt and debris that hits the front of the car, which can help protect the car's paint and reduce damage.
In most cases, yes. Front air dams are available for a variety of makes and models of cars. However, it's important to note that the effectiveness of the air dam may vary depending on the design and aerodynamics of the specific car.
The difficulty of installing a front air dam can vary depending on the car and the specific air dam being installed. In general, it may require some basic tools and knowledge of car mechanics. It's recommended to have a professional mechanic install the air dam to ensure it is properly installed and does not cause any damage to the car.