I was quick to think Willard was on the wrong track as well... but lets let him work this through... the FEH in many cases works against conventional wisdom.
Examples:

The FEH gets higher MPG over hilly terrain, compared to flat....
The FEH gets higher MPG driving slower than faster...
The FEH gets higher MPG driving stop & go, than any steady speed...
The FEH gets higher MPG in high elevations ( Colorado Rockies ) than sea level...
The FEH gets higher MPG with the lowest Octane gas you can find....
( I get better MPG with 85 octane, than 87, but I have to be above 3500 feet of elevation to find 85 octane... I hear Russia sells 80 octane... wonder if they would ship me some?....... )

With custom "hybrid" engines... I think we need some 80 octane "hybrid" gas.

 

[quote=jmorton10;150653]I would think it would be similar to nitrous oxide, that doesn't burn either but it's an awful good accelerant. Adding it burns more fuel however, not less.

~John[/quote

If you add O2 to the incoming mix (NO2 or from your generator), the O2 sensors will fatten the mixture to bring the it back into stochiometric balance (during closed loop). A similar situation is the oxygenated winter gasoline that supposedly helps keep the gross poluters from being so gross, but costs folks with O2 sensors and mass-air meters gas milage nearly equal to the added oxygen, for the same reason.

MM

 

John, I strongly disagree that stopping and then going gives better gas mileage than keeping a moving speed. Anytime I stop, the energy (battery or gas) it takes to accelerate back to speed causes a drop in MPG in my FEH, always. The more stoplights I make, always yields me better mileage. The best mileage I find is above 20mph and below 35mph with no stops. Even slowing below 20mph will cause a drop in MPG trying to get back to cruising speed IMO. The only time I slow below 20mph to save gas is to get up a hill in EV. This is because I can recover speed on the downhill and get some regen.

Also, when I must come to a stop, I find it's better to kick on the ICE just before I use "L" to slow to that stop. This allows the ICE to use MG1 to charge, but regen holds RPM's down and reduces fuel consumption till I go EV near the stop. This lessens the hit on MPG, but if you have to stop, you have to stop.

GaryG

 

Well stated. The ECU will always meter fuel to the O2 present in partial pressure contained in the manifold. A supercharger increases the partial pressure, therefore increasing the available O2, so the ECU will enrich the air/fuel mix to bring it to stochiometric balance. An Oxygen generator does not change the partial pressure, but enriches the partial pressure atmoshphere in the manifold and the same thing occurs. Yes, either unit increases available power for a given throttle setting, but it also requires an corresponding higher fuel flow, so in the end the FE is a wash.

IMHO the only real ralue of a turbocharger is in situations where the atomspheric pressure is low, either due to altitude or extremely cold termperatures. The ISO standard day pressure of 29.92 In/Hg at sea level can drop considerably at 6 or 7 thousand feet in winter temperatures below freezing. The supercharger can then conpensate for the atmospheric pressure decrease due to altitude and also correct the termperature loss because pressurization also results in heat (Boyles Law). The result is better fuel vaporization, a denser air/fuel mixture into the ICE and increased heat and power out of it. If the engine breathes well enough under high and cold conditions without a turbocharger, then it is not necessary and offers no other advantange.

 

Actually the colder the air the denser, its warm air that lowers the density altitude from standard. If you are a pilot then you remember high, hot, and humid means danger.

 

True enough, but ignoring humidity for the moment, we are dealing with two rates here, one for pressure (about 50% of sea level at 5000 meters, depending on latitude and temperature, (ICAO Barometric Formula) and one for temperature (1.98C/1000ft ISO Standard Day per ICAO). If you compare the rates, pressure always wins and the Density Altitude will always be (considerably) above sea level at 5000 or 6000 feet, even on a very cold day. After all, that's why so many airplanes have turbochargers.

Actually, my reference to temperature was to point out the other benefit of the turbocharger. Thanks to Boyles law, we know that compressing air also heats it, and therefore improves fuel vaporizaton (vapourization for all you Canadians). In this day of engines with variable ignition timings this is a little less important, but it still is a factor in how uniformily and completely the mix distributes throughout the cylinder in the time available.

BTW Most of what I flew had several very big "turbochargers" on them with igniters on the backside of each one. We didn't worry too much about "high, hot and humid"!

 

Okay the 5LPM oxygen concentrator is not enough to really help.

But the theory is SOUND.

Let's say the ICE produces 23HP at 2200 RPM to move the FEH at 60MPH.

If I displace some of the nitrogen in the intake atmosphere with oxygen the ECU will react and throw in more fuel to keep the A/F mixture in balance.

The ICE might now produce 30HP at 2200 RPM and so we close the throttle to keep us at 60 MPH. We end up at 1500 RPM having in the process lost the engine frictional component for 2200 RPM.

Net gain in FE.

Do we realize that if all the nitrogen could be eliminated gas engines could be 5 times smaller...??

 

Fastmover- I thought you were saying the colder the air (at the same alt) was less dense than warm air. C-130s?

 

Not really. The engines are designed to be efficient at a higher rpm than 1500. Intake manifold tunning, camshaft profile all contribute to a efficiency band these are designed into the performance profile of the engine. The frictional loss is minuscule between 1500 and 2200.

 

Stop and go, with lots of Pulse & Glide, in perfect weather, gives me 68 MPG and up to 89 MPG on short trips.
68 MPG is about the Max. sustainable on longer trips, because at some point, around 10 miles, the HV battery gets too hot for optimal results ( IE A/C starts to come on... )

Gary, what steady speed gives you higher than 68 MPG on flat ground ???

I often say 48 MPG at 48 miles per hour.
YOU often say 50 MPG at 50 miles per hour.
Fine. Those are very close, and agreeable numbers.
But both your words, and mine, are FAR FAR FROM what this car is able to
do with lots of acceleration and deceleration. If some of those decels go all the way to a stop, it's not a big deal overall.

At steady speed, you get almost zero regen, and very little battery assist.

What color is the sky Gary? I say it is blue*.

* Cloudless DAY
* No visible pollution
* Local Noon
* Planet Earth

Go ahead, disagree. We need some Holiday Cheer.