EV Conversion - Power needed on Highway

[iss407]

I am converting a 94 Saturn SC2 to an electric vehicle. I am doing this on the cheap and I want to get the smallest motor I can that will handle the job. Electric motors are rated at continuous power. They can provide over 4 times that much power for short periods, the shorter the period the more power you can push through it.

Therefore I want to buy a motor rated at a continuous power rating for highway driving. My commute is 45 miles on a 55 MPH two-late highway most of the way with few hills. I want to know how powerful of a motor I need to cruise at or a little under the continuous rating of the motor. I want to go at least 50 or other drivers get very anoyed. 55 would be best. If they want to go faster than the speed limit they can pass me.

I will be doing a lot of aeromods on this car. I will remove the side mirrors and replace with cameras. I can put a very clean underbody tray on it since with an electric there is no exhaust and no oil or gas leaks to worry about. I will add some rear fender skirts as well. The SC2 has a low drag coeficient to begin with. I will also run LRR tires.

So, what kind of horsepower should I need to cruise at 55? I will be running through a manual transmission, so there are losses there to consider.

Also, what about the rear spoiler; will drag be better with or without it? And the car has pop-up headlights as well. I will be doing a lot of driving at night and I want to convert to HID anyway. Should I mount some new lights up front and leave the pop-ups down all of the time? I don't need to worry about blocking the grill since I don't need as much cooling as an ICE does.

Thanks for your expert advice.

-- Paul