I recently bought an '06 F250 6.0 diesel. I get the feeling there is a diffference in quality from one fuel brand to another based on the variance in price and exhaust smell. Am I right? If so, what should I be aware?

 

That is true and more noticeable with the exhaust smell from a diesel compared to a gas engine. The quality of most fuel today has gotten pretty bad in my opinion and especially diesel fuel.