I have found no posts of modder Recreational vehicles with EFI. So here is some info. Want to do a LOT, have a drag racer interested.
What I have learned. EFI systems for RVs are generally a combination of 2 types.
Alpha-N and Speed Density. These systems are OPEN Loop. Some bikes have an O2 sensor which makes then a CLOSED Loop system. Harley uses ion sensing which is spark sensing.

The OPEN Loop systems typically use 7-8 of the following sensors;
Crank Position, Throttle Position, Atmospheric Pressure, Intake Air Pressure, Air Temperature, Coolant/Engine Temperature, Cylinder Identification, Lean Angle

Where I got info;
How Electronic Fuel Injection (EFI) Works - How To | Motorcycle Cruiser

I know for a fact that if the system is computer controlled, and the system does not use the O2 sensor in a dynamic fashion (real-time AFR modulation) there will be no increase in fuel ECONOMY.

The ECU must have the ability to remap itself, or that becomes the job of the owner/technician and will require some skills in that area to assure the greatest increases in all areas.

There WILL be an increase in power and a reduction in emissions, as I have found by modding two Harley's. Both had an O2, but it was not equipped with adaptive memory and so there was no mileage increase. In fact, the owners noted a slight decrease in mileage.

I still no not have a full understanding of these systems and those in the shops around me being unwilling to share such information I have not had the opportunity to research them further. So, I am REALLY grateful for this post!

Thank you, Prescott!

Thanks Prescott and Ron! Prescott that video is another Great instructional tool for understanding how EFI works, it's a Gem!

And Ron you're spot on--if a computer on EFI equipped Anything only uses O2 dynamic input on a limited basis, Or if the computer can't re-plot fuel delivery maps, then we are at square one for economy gains. In that situation it is up to the operator to hold back on using newfound extra power to see MPG gains.

But, I might also guess--EFI RV owners and racers might be well satisfied w/power & emissions improvements anyway.

And for cars/trucks that have EFI systems like this, I'm gonna scratch my head and think...

Thanks Prescott for posting this one!

TracyG Gadgetman Reno