HMmmmm, if my feeble memory serves me right, I believe the U.S. Navy used "Nitrogen" in the oleo struts of their carrier based A/C to preclude a catastrophic event (dieseling explosion in the strut on landing???). Generally speaking, anything explodable on a carrier deck is not well received (with the exception of selected ordance destined for some dusty, lonely, poverty stricken place). Your C-4 model has often been described as having a "cockpit" like ambiance and that is a more accurate representation than many folks may realize.
That issue aside, I am not a chemical or fuels kinda guy; but is it possible that the 'Nitrogen" being a rather inert and non-combustable material (gas) may be added to reduce toxic by-products (lead) in the exhaust becasue it may 'slow" the fuel ignition and flame front in the cylinder as well as legacy additives which have been used to reduce pre-ignition????
Not an answer, just trying to figure out why "Nitrogen" would be an additive to gasoline. Which leads to the next issue just what will "Nitrogen" do to the Cats????? HMmmmmmmm, clearly, this calls for much more pondering and contributions from those much more knowledgeable than I, but I do like to ponder these issues late at night in front of the fireplace, with the nectar of the old country (single malt of course).
Yes, I have a problem!