mark yates:
I also call BS on your low top speed 15 HP figure. The Prius can do about 33mph on it’s tiny motor.   

The G1/2/3 Prius is capable of 42 MPH and the newest is able to do 60 MPH in electric mode.
This will improve your argument even further: the limitation isn’t because of a lack of power, it is due to revolution limits on the motor used in the power split device.

I would imagine this car could do 60mph. Remember air resistance increasses with the square of the speed, so 20mph = very very low wind resistance.   

The force from wind resistance increases with the square of speed. But since power is force times speed, then that makes the increase in power go up with the cube of speed.

Rolling resistance is a constant force. That makes the power to overcome rolling resistance a linear relationship with speed.

When you have the power being a sum of one factor that goes up with the cube and the other goes up linearly, you end up with one dominating at low speed and the other dominating at high speed. In most cars the crossover where they are roughly equal is around 40 MPH. Below 40 MPH you can pretty much call the power – speed relationship linear, and it quickly becomes a cube relationship over 40 MPH.

What I think is you won’t be able to overtake a car and jump from 40mph to 60mph… unless you’re going to push the battery beyond it’s “turn off range”… and then the battery is not going to be happy “assisting” while you try and maintain speed up a long ascent. Even in the flat UK, you get motorways that climb 200metres over 4 miles on 7% gradients where lorries get stuck in the slow lane doing 50mph… this car will be in that lane.  

As I commented above, your theory is based on Audi managing the battery like the Volt. If Audi allows you to fully charge the battery back up with the range extender in anticipation of an upcoming mountain pass, then the performance could be far better.

CaptJackSparrow: Ever see those Jeeps with a big red “Jerry can” strapped to the back of them? And their exposed!

That’s a Jeep thing. You would’nt understand it. I sure as h%#L don’t.

Kind of upsets me to see your, “…Every hear of rounding to significant digits folks? Good job at removing the nonsensical digits Lyle.” post has a -6 on it. Oh well, that’ why I try to not look at those numbers (which are usually covered up by the +/- symbols in my IE7 anyway).

Yeah, everybody hates engineers and our obsessions with accuracy, resolution, numeric overflow, etc, but when a bridge collapses or a car has unintended acceleration then it suddenly matters.

Er, what was this thread about again? Oh yeah, Wankels