Nitrous Oxide for FE?
 

Would it be economically viable to use a tiny bit of NOS to get to cruising speed? I'm talking about a continuous miniscule amount, compared to what is used for performance. I also wonder if a continuous miniscule amount would help FE at speed. I'm sure it would, but am not sure if it would be cheaper than just using gas.

It would have a simler affect as using a turbo, because Nos is not a fuel, it is an oxidizer, if I understand correctly it contains oxygen, and releases it when heated, it might help with mileage simply because it would reduce pumping loss to a point, and speed flame spred, increasing torque.
I've seen very small NOS setups for pocket rocket motorcycles, and have wondered how they would do on a motorcycle like my cb125 if I re-geared it for lower engine rpm, then when I needed a bit of speed turn it on for a few seconds, if you did add it to a car I would think that would be the way to go, because I'm not sure how it affects engine temp, or stress if you ran it all the time, but your engine already puts out more power then you need most of the time, so using it for things like merging on to the freeway might work well.

Nitrous essentially only supplies oxygen to the motor, you'd also have to add a proportionate amount of fuel.

Really, the only reason to use nitrous is that you can't get any more air into your motor when the throttle is wide-open (i.e. racing), it will allow you to cram some very dense oxygen into the motor (allowing you to add extra gasoline, which is where the extra power comes from).

Nitrous will not help whatsoever with fuel efficiency.

Perhaps you want to think about adding other fuels like propane or nitromethane...

-Bob C.

I guess it would help with fuel efficiency if you cut all but one cylinder and relied on a nitrous shot in that as your only means of accelerating worth a damn.

Edit: actually, second thoughts, it would help a carbed motor I think, because you could run leaner with less throttle opening,... an EFI motor... the ECU will just look at the O2 and pour in more fuel (And if you can stop it doing that with an O2 sensor interceptor, you can make it lean out without adding NOx in the first place)

Edit: 3rd thoughts, bleed it to the back of the O2 sensor and see what happens.... if it provides more oxygen ions there the cell will not balance at the lambda output value of 0.45 until there's a lot more O2 in the exhaust stream....

if you were using such a small engine that you had to spend a long time re-accelerating during P&G, then you could use it to accelerate more quickly and thus burn less fuel by running the engine for a shorter amount of time.

The motorcycle engine in the Metro got me thinking.. If a very small [motorcycle] engine was put into a small car with low cd, and used NO2 for accelerating, it would get excellent FE, maybe even that of a large motorcycle.