[redtracer]

Hey guys, I'm trying to recreate a Chrylser 300 in this web sites MPG calculator so I can see how a Cd change affects mileage.

My problem is even though I don't have engine or drivetrain efficiency for this car I'm having a really hard time recreating the real world gas mileage I've gotten with this car. I frequently get ~30 MPG at 75mp/h, but to get the calculator even close to that I need to do crazy thing to the numbers, the biggest one being bumping engine efficiency up to a whopping 30%

Here are the numbers I was using (in order from top to bottom)

4200
0.0125
0.36 - Known accurate value
25.8 - Known accurate value
33557
0.25 - Guessed Value
0.85 - Guessed Value
0
1.225

With these numbers I get 19.27MPG @ 75mph. That is so far off what I get the real world that some of these inputs are way off, or the calculator doesn't work how I think it does. I've tweaked with the numbers but to get it close to 30 I need to do some crazy things that are just flat out wrong.

So my question is this: Does anyone know if there is a "baseline" or "standard" they used to make this calculator? Some vehicle where you put the values and it comes out correct? I want to use this information for a report, but as of right now I just can't trust it because it's giving me values that are just bananas and make no sense.

Thanks guys.