How To Get 80-100 MPG on the HWY in FFH/CMAX Hybrid

[ptjones]

OFFLINE ptjones

I have about reached the limit for AERO and Temperature Efficiency Improvements like Grill Covers and Wheel Covers for my CMAX. With temps in the 80's*F I can average 50-54mpg at 65-70mph with no A/C on the HWY. Not bad, but I'm still looking to improve more. I remembered someone had said the ICE is very inefficient so I looked it up and to my surprise it is only 25-30% at best. WOW So looking at GOV site and Wikipedia

 

http://www.fuelecono...v/feg/atv.shtml

https://en.wikipedia...gine_efficiency

From Wikipedia:

"Modern gasoline engines have a maximum thermal efficiency of about 25% to 30% when used to power a car. In other words, even when the engine is operating at its point of maximum thermal efficiency, of the total heat energy released by the gasoline consumed, about 70-75% is rejected as heat without being turned into useful work, i.e. turning the crankshaft.^[1] Approximately half of this rejected heat is carried away by the exhaust gases, and half passes through the cylinder walls or cylinder head into the engine cooling system, and is passed to the atmosphere via the cooling system radiator.^[2] Some of the work generated is also lost as friction, noise, air turbulence, and work used to turn engine equipment and appliances such as water and oil pumps and the electricalgenerator, leaving only about 25-30% of the energy released by the fuel consumed available to move the vehicle.

In the past 3–4 years, GDI (Gasoline Direct Injection) increased the efficiency of the engines equipped with this fueling system up to 35%. Currently, the technology is available in a wide variety of vehicles ranging from less expensive cars produced by Mazda, Ford and Chevrolet to more expensive cars produced by BMW, Mercedes-Benz, and Volkswagen Auto Group."

 

As you can see about 30% of the energy is absorbed by the cooling system from piston, cylinder walls and cylinder head and another 30% goes out the tale pipe.

 

This got me to thinking about using a material that has very low Thermal Conductivity and as it turns out I help to develop STAR21G, a

black material with Thermal Conductivity of: 1.25 W/(m K) at 25*C, 160 times lower than Aluminum,34 times lower than Steel.

Aluminum: 205 W/m K) at 25*C

steel: 43 W/m K) at 25*C

 

Here are the advantages that I can think of.:

 

1. Potential MPG improvement of two times.

2. Almost instantaneous operating temp, no energy being absorbed by combustion parts and lower pollution.

3. Eliminate the need for a cooling system there by saving the cost for having one, may need oil cooling.

4. Cut pollution in half by using half as much gas for each mile.

5. ICE cars will be cheaper to own and operate then All-electric Cars and create similar amount of air pollution assuming they use coal fired power to charge battery.

6. Hybrids could improve MPG's more if we can use exhaust gases to run a steam engine generator to charge HVB from using exhaust gases.

7. Would increase HP and Torque by a factor of two for the same ICE design.

8. There maybe more advantages and I will add when I or someone else comes up with them.

 

I'm thinking 100 mpg/ 1400mi. on a tank with a CMAX Hybrid on the HWY for 2018. (Maybe 2K miles with Hypermiling)

 

This isn't a cost effective solution for current CMAX/ICE vehicles, but for Future Hybrid/ICE vehicles this could be a huge improvement in MPG/HP/ Torque and cheaper to make. IMO anyway. I might try to add this to my ICE now that I'm out of warranty if I get the opportunity. (133K mi)

 

It would be interesting if I could get someone at FORD interested in my idea otherwise I'm going to put this information out to the Public Outlets and see what happens. I have applied for a patent too.

 

Let me know what you think.

 

Paul

 

I thought I might clarify how a ICE (internal combustion engine) would work using STAR21G, black material. This is the way our 4 cycle engine works :

 

Induction Cycle pulls in cool air from intake through cylinder head into combustion chamber cooling cylinder head, cylinder walls, piston and valves.

Compression Cycle the air in the combustion chamber compresses further cooling it until the piston gets close to the top where it gets hot and fuel is injected into combustion chamber.

Power Cycle fuel is burned and is slightly absorbed into combustion chamber.

Exhaust Cycle hot gases are pushed out of combustion chamber with a little more heat absorbed into surfaces of combustion chamber.

 

As you can see about half of the time the combustion chamber is being heated up and the other half it is cooling down. Because the ICE absorbs very little heat it shouldn't be that hot on the outside of the ICE. This is also why you will double your MPG's, because 30% of the total energy lost to cooling system won't be lost now. Or 60% of the energy will be moving the car and 30 % will be going out of the exhaust pipe.

 

Paul

Edited June 12, 2016 by ptjones

[talmy]

Reminds me of the work done on ceramic cylinders some time ago. In either case while the 30% lost to the cooling system won't occur, without better conversion of the heat to energy (such as with a Sterling cycle engine) it's just going to go out the exhaust.

[rjent]

Some testing has been done to recapture much of the exhaust heat with different devices and convert it back into electricity charging the HVB. One experiment comes to mind of diesel trucks improving mileage by 30 percent by recovering the heat energy.

[Waldo]

Better go back to school Paul, an ICE doesn't steal the heat away from the combustion process, it absorbs the heat because it's got nowhere else to go. It's all about thermodynamics, you can't turn all of the combustion energy directly into pressure without also generating heat. Once you've generated the heat, the energy is already lost, the only thing you can do is turn that heat back into something useful. As talmy says, the heat is just going to go out the exhaust instead.

 

Heck, even by your own data aluminum has 4 times the conductivity of steel, and yet the net difference in efficiency between steel and aluminum block engines is pretty much zero.

Edited June 13, 2016 by Waldo

[ptjones]

Better go back to school Paul, an ICE doesn't steal the heat away from the combustion process, it absorbs the heat because it's got nowhere else to go. It's all about thermodynamics, you can't turn all of the combustion energy directly into pressure without also generating heat. Once you've generated the heat, the energy is already lost, the only thing you can do is turn that heat back into something useful. As talmy says, the heat is just going to go out the exhaust instead.

 

Heck, even by your own data aluminum has 4 times the conductivity of steel, and yet the net difference in efficiency between steel and aluminum block engines is pretty much zero.

Did you read the whole Post including the links? The point of my Post is my material doesn't absorb heat so you could put half as much air/fuel mixture in the combustion chamber and end up with the same amount of heat energy/power. It is possible that the temperature of gases would be higher to create the same energy/power with less molecules of gas to work with. Lubrication of cylinder walls maybe a problem with higher temps. All these issues have to be researched to come up with viable solutions.

I do know Corning worked on this idea in the early 90's and stopped for unknown reason. :)

I couldn't find any real info on Aluminum vs iron efficiency differences other than Diesel Trucks use iron and my new 2.7Liter V6 F150 has Cast Iron Block for better MPG's. :)

 

Paul

[Waldo]

Did you read the whole Post including the links? The point of my Post is my material doesn't absorb heat so you could put half as much air/fuel mixture in the combustion chamber and end up with the same amount of heat energy/power.

 

Uhh, no, that's not how it works. When you burn fuel you create a chemical reaction. That chemical reaction produces heat, it doesn't produce "power". The rapid heating causes expansion of the gases, which creates pressure, which is what moves the piston. If you put half as much air/fuel in, you get half as much heat and you get half as much pressure (probably not linear, but generally so). In other words the heat is what makes the power, it's not a byproduct. Once the piston is at the bottom of the stroke, you've got the same amount of heat left inside the cylinder and that has to go somewhere, whether it's absorbed into the engine or pushed out the exhaust. With your material it would all be going out the exhaust, which would make exhaust temps so high that the catalytic converters wouldn't work anymore, so you'd have to find a new solution for that unless you want to actually produce more pollution, not less.

 

[ptjones]

Maybe with the high temps you wouldn't need a catalytic converter and then use exhaust heat to run a steam engine/DC generator or some other kind of DC generator to charge HVB. :)

 

Paul

[ptjones]

Here is a YouTube video on how our Hybrid ICE works:

:)

 

Paul

[ElectricFan69]

What you're referring to is called an 'Adiabatic process', and has been the 'Holy Grail' of heat engines. Much like that mythical object, the adiabatic engine has been fruitless search.

 

In any internal combustion engine, the pressure rise and temperature rise are closely related - and in an Otto cycle engine so is 'pre-ignition'. Materials science aside, you navigate a fine line between efficiency, pollutant production (NOx, in particular), and cost/durability. If you get combustion chamber temps too high, NOx production will end up being a BIG problem. This is part of the issue that drove VW down the cheating trail - they had high combustion temps, which were great for FE, but terrible for NOx pollution. An engine that creates poisons is not a socially acceptable solution. High NOx levels are damaging to lungs, and a significant breathing irritant at moderate levels.

[ptjones]

I'm not sure if comparing a Diesel engine to a Atkinson Hybrid engine works if you watch the video. In VW case they were gaining 5-10% FE, in my case getting 30+%/ 60+ MPG even if NO2 go up mpg's will compensate for it. :)

 

Paul

[ElectricFan69]

I'm not sure if comparing a Diesel engine to a Atkinson Hybrid engine works if you watch the video. In VW case they were gaining 5-10% FE, in my case getting 30+%/ 60+ MPG even if NO2 go up mpg's will compensate for it. :)

 

Paul

In a word - No. Reduced fuel consumption won't make a difference if the total NOx emissions exceed allowable limits. There is a statutory limit for light-duty vehicles at well under a gram/mile. See the EPA document for the limits by vehicle tier. Maximum allowances vary by the emissions tier the manufacturer is trying to hit - which will determine the places where they can sell the vehicle. Some areas of the country have particular sensitivity to NOx emissions and suffer more from both air quality as well as watershed acid increase ("acid rain" resulting in NOx further oxidizing into nitric acid.

 

A second set of issues with adiabatic combustion chambers is lubrication. Conventional ICE engines with 'normal' materials have strict limits on surface temperatures in any lubricated areas driven by lubricant tolerance of temperatures. This also has / creates issue of managing cylinder sealing and gas blow-by. If you get too high temps on any surface swept by piston rings, you will lose lubrication - with resulting engine wear and eventual failure. You also increase oil deterioration, which changes/reduces OCI.

 

As to distinction between Diesel and Atkinson/Otto cycle engines - for this purpose, there isn't one. The different cycles have somewhat different emissions profiles related to how the combustion process happens and how fuel is mixed in the combustion chamber, as well as the chemical characteristics of the fuel. Diesel typically has remarkable issues with particulates and, due to peak combustion temps and its typically lean air/fuel ratios, a significant problem with NOx. Atkinson and Otto cycle can also have issues with NOx - but the other combustion by-products typically allow reduction/oxidation catalysts that are fairly well-understood.

 

Piece of trivia: 30+ years back a brilliant mechanic / race car engine designer Henry "Smokey" Yunick built working prototypes of 'hot vapor' phase 1 adiabatic engines that did much of what you're describing. There were also problems that nobody has been able to figure out effective solutions to that have prevented commercialization of the engine design. Google "smokey yunick hot vapor engine" and enjoy...

Edited June 14, 2016 by ElectricFan69

[ptjones]

The only similarity I see with "Hot Vapor Engine" is higher temperatures, but not as high as 2600*F. The my material could be used for the cylinder head which doesn't have a lubrication problems. I also think the piston could be used, because it wouldn't be transferring heat to the cylinder walls. If the exhaust gases are to hot for Catalytic Converter, you could run steam engine/ generator lines before CC to remove some of the heat and make steam for steam engine/ generator to charge HVB. :)

 

Paul

[Waldo]

Where's all the water going to come from to make the steam?

[ptjones]

Where's all the water going to come from to make the steam?

That would have to be self contained, Haven't done much R&D on creating DC Volts from heat, BMW has been doing alot of R&D on it. :)

 

Paul

[ElectricFan69]

Where's all the water going to come from to make the steam?

The working fluid - whether it's water or anything else suitable for the temps desired (you would want the working temperature/ pressure ranges to involve phase change for sake of efficiency - a great way of moving high amounts of energy). A Stirling cycle engine of some sorts could easily be used for 'thermal compounding'. Magazines like "Popular Science" have had 'breakthrough' articles on this technology for better part of 70 years. The deal-breaker issues here are cost, weight, and packaging, plus safety - a high-pressure system that's compromised (e.g. in a wreck) can 'blow up REAL good'. You could easily make this a closed system - using a fixed amount of working fluid cycling between the heat source (ICE exhaust), the heat engine, and a condenser.

 

Fuel prices would have to rise by an order of magnitude for that to be a cost-effective add-on. The other factor of this sort of add-on is that it's only effective in steady, relatively high-load power demands - making it ineffective for most folks. Long-haul trucks are a feasible application, but again, cost and weight make it a hard sell in days of cheap fuel.

[ElectricFan69]

The only similarity I see with "Hot Vapor Engine" is higher temperatures, but not as high as 2600*F. The my material could be used for the cylinder head which doesn't have a lubrication problems. I also think the piston could be used, because it wouldn't be transferring heat to the cylinder walls. If the exhaust gases are to hot for Catalytic Converter, you could run steam engine/ generator lines before CC to remove some of the heat and make steam for steam engine/ generator to charge HVB. :)

 

Paul

 

 

Any engine with combustion chamber temps that high will create impossible-to-deal-with amounts of NOx emissions. Thermal NOx is inevitable when temps exceed 2000F and there is any free oxygen. Catalytic elimination of NOx can be done, but has its own costs and problems. Keeping combustion chamber temps below the NOx zone has been a critical goal ever since we recognized it as a toxin.

Reading 'between the lines' in some of the articles on Smokey's brainchild, excessive or hard-to-manage emissions, as well as problematic 'pre-ignition' and resulting mechanical abuse were the issues that he couldn't really overcome.

Edited June 16, 2016 by ElectricFan69

[Automate]

A Stirling cycle engine of some sorts could easily be used for 'thermal compounding'. Magazines like "Popular Science" have had 'breakthrough' articles on this technology for better part of 70 years

 

Just came across a story today claiming a Stirling cycle engine that gets 58 mpg in an F-150 and 100 miles per gallon in a smaller SUV! It also uses hybrid technology, but rather than supplementing the ICE the Stirling replaces the ICE. The Stirling engine is designed to have physical dimensions similar to a 4 cylinder ICE.

http://www.khou.com/features/san-antonino-man-has-engine-that-gets-100-mpg/242673922

 

http://www.foxnews.com/leisure/2016/06/15/man-builds-100mpg-engine-using-200-year-old-technology/?intcmp=hpff

Edited June 16, 2016 by Automate

[ptjones]

I was wondering if you enrich the fuel mixture, would that use up any extra oxygen so Nitrogen Oxides wouldn't be able to formed? :)

 

Paul

[ElectricFan69]

I was wondering if you enrich the fuel mixture, would that use up any extra oxygen so Nitrogen Oxides wouldn't be able to formed? :)

 

Paul

That has been a strategy for managing Diesel emissions, where particulates and NOx are 'trapped' and periodically 'burned off' by enriching the mix. Consequence is increased fuel consumption.

[MeeLee]

Original poster is incorrect.
Gasoline engines do 40-45% efficiency nowadays.
Especially 3 or 4 bangers, and especially atkinson designs.

One of the main issues is final drive gearing. Most engines rev 500-1000RPM too high in final gear, resulting in a 10MPG loss overall.

Another way to increase efficiency, is using a fuel warmer (warm the fuel from engine heat, prior to injection).

Third, hot air intake (will reduce HP/torque)

Fourth, use a water vapor injection system. Water vapor increases the density of air, and works well on torquey engines. There is research done on steam getting into the crankcase, causing oil pollution though.
But for short boosts it can work really well.

Another thing that can be done, especially when increasing gear ratios, is mixing a tiny bit of 2 stroke oil in the gasoline, at a 1:128 ratio (1oz of oil / 1 gal of gas).
My personal tests have shown that 1:100 ratio is too much, and 1:300 doesn't do much.
1:128 is easy to calibrate, or ~1:200 ratio (~10 oz in a 12 gal tank).
It slows down pre-ignition, it lubricates the upper pistons, and increases performance; though might interfere with modern car O2 sensors.

At a low enough ratio the oil is more treated like an additive.

[ElectricFan69]

On 3/17/2021 at 11:43 AM, MeeLee said:

Original poster is incorrect.
Gasoline engines do 40-45% efficiency nowadays.
Especially 3 or 4 bangers, and especially atkinson designs.

One of the main issues is final drive gearing. Most engines rev 500-1000RPM too high in final gear, resulting in a 10MPG loss overall.

Another way to increase efficiency, is using a fuel warmer (warm the fuel from engine heat, prior to injection).

Third, hot air intake (will reduce HP/torque)

Fourth, use a water vapor injection system. Water vapor increases the density of air, and works well on torquey engines. There is research done on steam getting into the crankcase, causing oil pollution though.
But for short boosts it can work really well.

Another thing that can be done, especially when increasing gear ratios, is mixing a tiny bit of 2 stroke oil in the gasoline, at a 1:128 ratio (1oz of oil / 1 gal of gas).
My personal tests have shown that 1:100 ratio is too much, and 1:300 doesn't do much.
1:128 is easy to calibrate, or ~1:200 ratio (~10 oz in a 12 gal tank).
It slows down pre-ignition, it lubricates the upper pistons, and increases performance; though might interfere with modern car O2 sensors.

At a low enough ratio the oil is more treated like an additive.

The more nuanced and accurate is that the PEAK efficiency of ICE is approaching 40%, rather than the AVERAGE efficiency.   Toyota and Hyundai have made much hash (and been recognized by SAE) for the improved efficiency, and their best ICE is just hitting 40%.  Specific to the Fusion ICE, the figure I've seen is in the low 30's.  Which is still much better than the 'average bear', but, still, a ways from the 45% number.

 

As to the 'right' cruising RPM - well, it really depends on the ICE tune. This includes intake and exhaust runner length, port shape, cam lift, bore/stroke ratio, ignition and cam timing and just about every other ICE design parameter. The Fusion/Toyota PSD does a commendable job of keeping the ICE in the efficiency 'happy place' that also avoids 'lugging' behavior and excessive NVH.  The electric motors do a great job of masking the relatively wimpy torque of the Atkinson cycle ICE.  The 'rule of thumb' for Otto cycle ICE is to run as near wide-open-throttle to minimize pumping losses, which typically includes low RPM and as much EGR as can be tolerated and still get reliable ignition.  Note that isn't driver input - it's the ECU telling the throttle body, fuel injection and EGR to go the efficiency happy place.

 

As to things like 'water injection' - well, it can be useful in managing pre-ignition, allowing higher expansion ratios and 'better' ignition timing, while keeping peak temps out the the NOx-ious range.  They have been in use under specific use cases that makes the expense and complexity 'worth it'.  Think high-boost turbo ICE. 

The biggest liability of high intake temps center around uncontrolled combustion - like pre-ignition.  

 

Including 2 cycle oil in an Otto cycle ICE will create significant emissions liability, as well as put converter flow at risk (excess ash causing plugging).  The increase is emissions makes it undesirable.  The devil's bargain that EU regulators made with tolerating high particulate and NOx emissions 'back in the day ' to achieve relatively good fuel consumption numbers really highlights how undesirable that is.

[MeeLee]

I'm getting 50mpg out of my 2.0 atkinson engine at 75mph, revving 1.25k rpm on the highway. The engine isn't lugging, since lugging  and predetonation are all electronically controlled (the throttle body won't open as far as to have the engine lug).

Running the engine at such low rpms, increases efficiency by well over 15%, compared to their design specs. Meaning even if they peak at 30%, gearing and proper load will easily up that number by 10-15%.

Most stock cars run their engines around 30-40MPG at this speed (2-2.5k rpm).

Pumping losses are greater than air friction losses for coasting (not acceleration).

 

Lugging a modern engine is nearly impossible, because it's electronically controlled and protected.

My understanding of lugging,  is to load the engine so heavy, that parts of the engine no longer are protected by the oil film, and start scraping metal on metal.

This can be due to high load, or slower movement. The faster the parts move, the more they will float on oil.

For most cars, it's nearly impossible to lugging am engine at 1k rpm and up when costing, and 2k rpm and up for acceleration.

This is the same for most engines, because they all are designed for the same (or similar) oil. (Usually ranging from 0W20 to 10W40) 

Edited March 27, 2021 by MeeLee

[ElectricFan69]

1 hour ago, MeeLee said:

I'm getting 50mpg out of my 2.0 atkinson engine at 75mph, revving 1.25k rpm on the highway. The engine isn't lugging, since lugging  and predetonation are all electronically controlled (the throttle body won't open as far as to have the engine lug).

Running the engine at such low rpms, increases efficiency by well over 15%, compared to their design specs. Meaning even if they peak at 30%, gearing and proper load will easily up that number by 10-15%.

Most stock cars run their engines around 30-40MPG at this speed (2-2.5k rpm).

Pumping losses are greater than air friction losses for coasting (not acceleration).

 

Lugging a modern engine is nearly impossible, because it's electronically controlled and protected.

My understanding of lugging,  is to load the engine so heavy, that parts of the engine no longer are protected by the oil film, and start scraping metal on metal.

This can be due to high load, or slower movement. The faster the parts move, the more they will float on oil.

For most cars, it's nearly impossible to lugging am engine at 1k rpm and up when costing, and 2k rpm and up for acceleration.

This is the same for most engines, because they all are designed for the same (or similar) oil. (Usually ranging from 0W20 to 10W40) 

You have obviously not driven certain Toyotas with the 3.5 and the 8 speed.  In the quest to maximize efficiency, light incremental throttle input from moderate speed cruise will do a 'herk and jerk' until the ECU decides to command a downshift.  Work-around is 'aggressive' throttle input.

 

You are right that most manufacturers do a good job of tuning out 'lugging' behavior, particularly with automatic transmissions.  The real cause is combustion instability - the combination of ICE load, and valve timing, ignition timing, EGR and RPM yields unstable combustion which shows up as mechanical roughness due to 'wrong time' cylinder pressure peaks.  The 'float on oil fail' isn't really a cause - more like a consequence of peak pressure exceeding oil film strength. Any significant duration of that will destroy bearings.  Smooth ICE performance requires peak cylinder pressure some time after top dead center of the power stroke - exactly how many degrees depends on the piston / crank / con rod geometry.  It also requires a smooth build of pressure - pre-ignition results in multiple  local peaks that load the piston surface unevenly.  This result in resonance / flop that is audible as 'ping'.    

I don't get what you're saying in 'pumping losses on coasting'.  With many modern ICE tunes, the fuel injection will effectively be shut off, thus no loss - the pumping is used to slow the car down.  Otto / Atkinson cycle pumping losses are at light-load cruise, where manifold vacuum is high.  That manifold vacuum requires flywheel energy to overcome - leading to a less efficient power output.  That is one of the things that makes Diesel cycle more efficient (other being high expansion ratio) - running without throttling air minimizes the pumping losses on the intake cycle to the pressure drop across the valves.  

As to minimizing RPM - that is really about minimizing frictional losses, including hydraulic losses.  Higher ICE RPM have more friction overhead.