[RedDevil]

Actually the best racing line through a corner is not the line with the biggest radius!

It would be if the speed was constant before, during and after the corner; which makes it a good approximation of the ideal line for hypermiling.

But in a race you enter the corner still braking, and exit it while already giving it throttle.
The speed in the apex needs to be slightly lower, so you can brake longer before the corner and accelerate going out.

I did not win 3 F1 Championships, but take it from someone who did:

http://www.youtube.com/watch?v=WhgOXVnHYXA

Now its not just the line you take, but also the speed at which you (try to) take it. The closer the speed comes to the limit of what the tires can bear, the higher the friction will be trying to slow you down.
You can compensate that with gentle throttle, but hypermiling is all about maintaining momentum through efficiency, not extra throttle.

If your speed was already low enough to go round the corner without tire squeal the biggest radius would be close to ideal.
If you have more speed you might choose a line that starts at a bigger radius (entering the corner slightly earlier at higher speed) and allow the friction to gently reduce the speed, and radius, throughout the corner; especially so if you do not need to speed up in the section after the corner.
Then there are corners where the road surface is not even, like the OP pointed out. Better run that ridge if it does not violate the ideal line too much...

There is no simple rule of thumb to prescribe the ideal throttle, line and speed for hypermiling corners, just like there is none for racing them; because in both cases there are too many variables at work.
Which makes hypermiling a true skill, just like racing.

There is a lot we hypermilers can learn from racing.