Drag HP vs mph

Ohhhh ... he said ;-)

Coef 'B' is 48x larger than Coef 'C', so Coef 'C' will become the predominant contributor to final power result at speeds over 48 mph. That sounds like a number within the range of expected. How are the Set Coef's supposed to be used ?

I would still like to convert the Coef's to Newtons. Is it wrong to multiply by 4.5 ? It seems so, because then the speed in meters/second would never get high enough to let Coef 'C' become the predominant contributor to total power.

Also, I'm starting to wonder if my column data is shifted, an error introduced when I removed quotation marks before I imported. Would you mind posting just the Prime Coef data in CSV format ?

 

Thanks.

In UK currently only door handle indent protectors are available for the "Prime" in 3m clear plastic. I've ordered a set.

Also some folk report problems.

Apparently bird fouling can cause permanent clouding of the 3m. And people have been told it came be removed without damaging paintwork. Someone posted on this site that the 3m took a hit and prevented paint damage, but the resulting dent in the body work could not be repaired due to the 3m and the 3m could not be removed without causing damage.

Posted via the PriusChat mobile app.

 

Maybe older formula generations but experience i have so far on 3 car's are all positive......

Posted via the PriusChat mobile app.

 

The target coefs for the Prime are:

Target Coef A (lbf) | Target Coef B (lbf/mph) | Target Coef C (lbf/mph**2)
18.816 ...................... 0.38689 .............................. 0.012501

To find the total resistance (force) in lbf for a certain speed multiply B by mph, C by mph aquared and add them together.
From here you have two options:
1. Multilpy the result by the speed in ft/sec to get total drag power in ft-lbf per second, divide by 550 for HP.
2. If you want to work in Newtons, multiply the result above by 4.45 N/lbf and to find the total drag power in Watts multiply by the speed in m/sec.

I found in the EPA data list that 3 cars (trims?) were tested by Toyota, each in 3 configurations. One of those cars was also tested by EPA.

 

If the Prime's Target Coefficient C above solely belongs to Aero Drag, then we can calculate the frontal area Toyota is using for the Prime:
For air density of 1.2 kg/m^2 at 20C and sea level, and for Cd of 0.25, the area calculates to 1.467 sq. m.

 

I gave you those two earlier.

 

At about the same time EPA published their "Certification Data: Annual Certification Test Data for Vehicles and Engines | Compliance and Fuel Economy Data for Vehicles and Engines | US EPA
This publication includes drag coefficients that were used for certification, and a comparison of some cars, based on Target Coefficients looks like this:




Quite different from the chart in the first post !?