Originally Posted By: Quest
This has been discussed before. Do a search.Q.
You're right, there's a ton of stuff, mostly anecdotal and not too informative.
Found this from shell which essentially says nothing new:
"The Nitrogen Enriched formula is proven to prevent build-up of gunk more effectively than gasolines containing only the minimum amount of cleaning agents as required by the EPA.
The new cleaning system is certified to meet the TOP TIER Detergent Gasoline Standard – voluntary standards designated by some of the world’s top automakers (Audi, BMW, GM, Honda, Toyota, Volkswagen) to try to raise the bar on fuel quality beyond minimum government criteria. Industry research has proven that a clean engine results in better fuel efficiency, reduced emissions, and overall optimal vehicle performance."
Any top tier gas can conform to those criteria.
There are many nitrogen based molecules - how about nitrogen tetroxide and hydrazine which are hypergolic rocket fuels? Shell's nitrogen is likely in an amine compound.
I've concluded that the nitrogen fortified gas is 50% legitimate and 50% hype. Also, they apparently put more of the additive in their premium grade.