if (I think you mean ethanol not ethonal, is it?) new types of cars are being fitted, it doesn't mean anythihg, as well as ability of potential isolation. In its present state, economy is global, and everything that is happening in the world affects it. US is the part of global economy, it is NOT isolated.
Chaos in the rest of the world will affect US. Plain and simple.
If US will be isolated and the rest of the world is going the way of globalisation, equillibrium shift is inevitable, and not in US' favor.