I have a 1990 Toyota Supra Turbo 4 speed auto. I've done some research about automatic transmissions and manual transmissions and what are the positives and negatives of each. (For example, MT is said to have better fuel economy by having the wheels roll without any influx of air.) A topic that I came across is that AT loose more HP, around 15% to 20% of the HP created at the wheels when translated from the engine (aka the crank HP), as opposed to MT loosing <15% at the wheels.
• What contributes to the AT loosing more of the HP generated at the wheels?
• What should one do to reduce the HP lost at the wheels without compromising the efficiency of the car? (Exhaust mods/manifold mods/ straight-piped via CAI reduces low-end torque [obtained info from a plethora of automotive sites].
• If the above answer is impossible to obtain, what should one do to decrease the amount of HP lost in an AT at the wheels?
Since I have a AT, I'm not necessarily going to do any modifications. I'm just using my car as a reference.