[sheepdog 44]

I started a similar thread a while ago. My crazy idea was to get the kind of oxygen tank that some people drag around with them, and pipe it in upstream of the intake. Just enough to get a 25-50% increase in the oxygen content. Heck, millions of years ago there was much larger percentage of oxygen in the atmosphere!

Edit: It seems the problem is oxygen storage. As a scuba tank full of pure oxygen could only give a 10% increase in oxygen over the course of one gallon of gasoline. In the case of a prius, since it's fuel efficient you get more bang for your oxygen buck. You can get a 125% increase in oxygen for 16 miles, or a 150% increase for 8 miles. Which means if there were no oxygen in the atmosphere at all (only nitrogen), you'd have enough oxygen in your scuba tank to drive your car for just 4 miles!

You wouldn't need a super strong engine per se to keep it from melting. You'd just need to run your engine 5X as lean as it normally runs. But if your'e only compressing and expanding oxygen, then there might be issues as RedDevil says.