Can Non-Hybrid Cars Get 100+ MPG Today?


We're not talking about hybrids here; our topic is cars powered by the basic IC-engine that relies on gasoline and not electric motors. Today's gasoline engines are not designed to combust/burn gasoline efficiently. Even with the advent of using high pressure fuel injection techniques that are computer controlled, we still fall short of the mark. Partly because liquid gasoline can't burn, only gasoline vapors burn, and there lies our problem. The same goes for injecting the high pressure droplets of fine-mist liquid gasoline that enters the engine cylinder using our current nozzle ejector technology, it doesn't all burn at the same time!

Engine designers assume that these droplets are instantly vaporized by the engine's hot cylinder walls, and then instantly explode/combust when ignited by the sparkplug. Not true, up to 2/3 of the fuel isn't vaporized and doesn't combust until later on in the cycle. The 1/3 that gets almost-instantly vaporized and burns will do so within the several thousandths of a second (Fig-1) it has before the piston moves down its 1/2-stroke (out of today's 4-stroke cycle) completing the engine power-portion of its cycle. This releases power and tremendous heat which indeed vaporizes the remaining ~2/3 of our fuel from its liquid droplet form, but too late. It essentially does so when the power stroke is almost over or the piston is just about ready to move into its up-stroke (2nd stroke of our four stroke cycle) phase. So, because of poor vapo-timing we have 2/3 of our fuel virtually wasted by exploding at near the bottom of the power stroke.

This incorrect explosive timing, which happens to most of our fuel, imparts very little energy into the crankshaft because its effective "moment" (a product of explosive force and radial-component distance from crankshaft center) is insignificant by then. Various attempts at adjusting the combustion timing spark hasn't made a significant difference. Even though ~2/3 of the fuel is now exploding and providing a huge force, its small "influence" arm distance is rapidly diminishing to zero, and any huge downward force times near zero arm-length is still zero.

Some clarification here, technically thermal-efficiency is not improved, pretty much all of the gasoline gets combusted today. That means the energy of the fuel is almost totally released, but not effectively used. The problem is the timing it takes to convert fuel-injected gasoline droplets into vapor to combust at the correct engine rotational time and extract that expended energy. If you did the math for any size engine rotating at say 3200 RPM, you would find that a 4-stroke engine can only extract that energy from combustion during one of the four strokes. And the time it takes to make that stroke happen is only about 9.4 thousandths of a second or 9.4 milisecs (msecs).

Now picture the piston just below TDC, all its valves closed, under pressure and containing all the fuel and air it needs to combust. At this point our deadly cocktail has about half of the 9.4 or about 5 msecs to complete combust after the timed sparkplug ignites it. The half factor exists because the max portion of our power stroke (moment arm) occurs at the mid-stroke of the piston sliding down and turning the crankshaft. If all of our fuel isn't combusted by then, the moment-arm or distance from the piston-center to the crankshaft quickly reduces to zero. Again, only vapors combust within a healthy 2 msecs (Fig-1), while fuel droplets take a relatively long time (>5 msecs) to vaporize before it can combust. Unfortunately nature is stubborn and vaporizes ~2/3 of our injected fuel droplets only during roughly the second half of the power stroke. So this huge amount of energy gets wasted because even though the forces of combustion are huge, its moment arm is rapidly approaching zero. Infinity times zero is still zero!

Engine designers/engineers have been plagued by this phenomenon ever since the creation of the 4-stroke gasoline or Otto cycle engine. We need to improve this intermittent combustion/explosion process by combusting all of our injected fuel at the correct timing sequence. This is accomplished by injecting only vaporous fuel which will produce ~3X the power we now get. Another way to state this is, for the same power that we now get from a gasoline engine, if we burned the fuel correctly, we would only need 1/3 the fuel consumption to get 3X the current MPG.

Picture of Can Non-Hybrid Cars Get 100+ MPG Today?
sort by: active | newest | oldest
1-10 of 38Next »
RT-101 (author) 4 years ago

Great questions about my theoretical holes! First, sorry for my delay as I’ve been busy on other tech things. Here are your answers:

1)      Education be damned! You strike me as a good thinker and perhaps tinkerer, and that’s all that counts.

2)      Advance timing doesn’t really properly address the issue of absolute engine power generation.

3)      Keeping a Gasoline Vapor:  Let’s assume our gasoline mixture has the average molecular composition of C10H22 (molecular weight of 142 kg/kmol) which yields a stoichiometric fuel/air ratio of 0.0673 or your definition of 15:1 air-to-fuel ratio. Thermodynamic tables of vapor pressure (by extensive testing of different gasoline mixtures) states that at an ambient (engine cylinder) pressure of 2 atmospheres (30 psia or 2.026E+05 Pa) we need a temperature of ~310 F to keep the gas a vapor. Now at typical gasoline engine compression ratios of 6:1 or 6-atm or ~90 psia we must keep the vapor at or slightly above ~500 F to keep it a vapor or it will compress back to a liquid.

4)      Auto Ignition & Controlled Detonation:  So I inject my vapor at a temperature of 500+ F into the cylinder and it stays a vapor. Now auto ignition occurs at around ~495 F, but that assumes I have enough air (oxygen) handy to ignite the fuel vapor, namely from at least 10 up to 50 times the amount of fuel vapor mass. We’ll play some thermodynamic games here and make sure that the combo of incoming air temperature plus gasoline vapor temp yields the right temperature mixture of just under ~495F so we don’t explode! Even if we go another 10 to 15 F lower than this to absolutely preclude detonation, so what! The few miliseconds (ms) we have, due to RPM piston-motion compression before controlled detonation,  can’t re-condense more than maybe 5% or so of our vapor, so we combust 95% at our controlled timing for a max power stroke. Compare this to today’s ~15 – 25% combustion of available fuel droplets for power and we’re ahead by a factor of at least 3X if not 6X !   Totally mind blowing!

5)      Cold Starts:  We’re talking about warm, steady-state engines here. I can’t give you everything! Yes, initially our cold engine won’t be too much better than today’s ratty engines. So how long does it take to warm up your engine?

6)      NOx Emissions:   NOX or nitric-oxides are oxides of nitrogen typically NO and NO2 compounds. These compounds mix with water vapor (H2O) in the atmosphere to form nitric acid (HNO3) or acid rain which is bad. NOX only forms at very high temperatures like that of our vapor-combustion engines. So how do we stop it? The chemistry of how NOX forms is not totally understood during its intermediate stages where it first forms NO then NO2. Wikipedia is getting much more reliable and now properly states that the formation chemistry takes up to 10 seconds to form a 50% NO2 concentration or 10,000 ppm from an initial formation of 20,000 ppm of NO concentration (lower ppm’s imply longer formation times). Taking this further, we can expect our NO formations to also take some minimal period of time beyond just forming instantly. Let’s assume that since it forms first, it therefore forms more rapidly than NO2 by a factor of at least 100 or instead of 10 seconds it takes 0.1 seconds or 100 ms. Even if it’s faster again by another say factor of 10 times (making it a total of 1000 times faster), that’s still 10 ms needed to form its chemistry. Any four stroke IC-engine running at 2500 RPM only has 12 ms for its power stroke to end. Within that total piston stroke time period, the above calculates a detonation time of ~2 ms required for complete combustion. Then the gas expands to create the remaining power stroke with ~10 ms left. We therefore form only about 2/12 or 17% of today’s NOX emissions. Our engine detonates 100% within only 2 ms while today’s engine keeps burning and forming NOX over the entire 12 ms stroke. Actually we generate even lower pollution since today’s cars continue to burn even while exhausting its combustion products into the manifold. So it can easily burn for another 12 ms, making our ratio for NOX production as low as 2/24 or only 8% of today’s cars.     

I have been very interested in experimenting with increasing fuel efficiency in ICE vehicles. I will start out by saying I am a Layman. I am not educated in thermodynamics. I work as a Diesel technician. I understand ICE power plants. I see only small holes in your theses. Timing, good starting point. advance timing will produce more HP. It comes with a cost (heat). Phase change of fuel, How do you plan to over come the pressure in the cylinder and prevent phase change from pressurization of the vapor? Higher compression ratio? Now we need to run gasoline engines with detonation ignition. This creates other problems. Cold start conditions. What do we do for that? One last thing.Would NOx. be higher?
Kiteman5 years ago
[citation needed]
RT-101 (author)  Kiteman5 years ago
While citations and references are always important when you publish technical designs as I have in the past, with the advent of the Internet and resources like Wikipedia, etc., sources are becoming as ubiquitous as the air we breath. Anyway, Instructables and Forums don’t require credentials do they? Although I definitely would provide DARPA with appropriate references and theoretical analyses should they be interested in contacting me. However, I've worked for them in the past and I won’t move to contact them over this concept!

Kiteman RT-1015 years ago
When you are making *any* technical or scientific, reliable data is an absolute requirement, even if it's just a link to the peer-reviewed research upon which you base your claims.

You make several assertions about the assumptions of engine designers, yet an actual engineer is contradicting you, and you seem to think you are being complimented!
  • "Extraordinary claims require extraordinary evidence"
  • "Onus probandi incumbit ei qui dicit, non ei qui negat"
  • "That which is asserted without evidence can be dismissed without evidence."
Ergo, I dismiss your claims.
RT-101 (author)  Kiteman5 years ago
I respect your feedback and feel compelled to respond.
Not wanting to be dismissed summarily, I’ll take you up on your challenge of evidential inferences. However, I’m a believer that too many references just lead to confusion, and in the end, one just has to make up their own mind as to feasibility. I’m also currently preoccupied with other things and can’t create a prototype of the engine concept discussed here, however, I’ve completely analyzed and designed a technically workable concept.

Out of respect for your feedback, which I’m trying to solicit through these blogs, here is historical evidence to make folks think. I've culled only those technological achievements where prototype hardware was built and shown to dramatically improve IC-engine performance while also back dating my evidence to the start of the 20th century:

1) 1903; Wright Brothers design/built their aluminum engine with a pre-mix vapo-chamber getting perhaps 1.5X more power output for flight.
2) 1920’s; G.A. Moore; US patent 1,633,791 (1927) for a vapo-carburetor that got ~35% more mileage over existent equipped engines.
3) 1930’s; C.N. Pogue of Winnipeg Canada, US patent 2,026,789 for an exhaust heated vapo-carburetor that demo’d 200 MPG.
4) 1940’s; J.R. Fish; vapo-carburetor, US patent 2,775,818, tested by Ford Motor company and showed 1.33X improvement.
5) 1970’s; Kendig Carburetor in LA; 2X mileage increase plus 50% pollution reduction, used a vapo-design heat exchange carburetor. 
6) 1972; A.L. Smith, NASA engineer; US patent 3,640,256, a vapo-carburetor, no reports on mileage.
7) 1973; J.R. Martin research engineer at Shell Wood River Refinery, CA; modified a 1959 Opel and won a mileage contest by driving 14 miles on 134 grams of gas, extrapolates to 298 MPG; engine well insulated and used a vapo-carburetor concept.
8) 1977; T. Ogle, El Paso, Texas; got 120 MPG (4X) on an evaporator-carburetor design using absorptive, wicking surfaces to evaporate fuel.
9) 1981; Henry “Smokey” Yunick. Daytona Beach FL, US patent 4,862,859, got 51 MPG (~2.5X) on a vapo-carburetor design where he modified a Pontiac Fiero.
10) 1984; J. Gilbert, Suffern, NY; built a gasifier-carburetor and got 2.5X increase in MPG using his 1981 Ford Escort control car.
11) 2011; G. Parker, developed the ALE, a 3-wheel plastic car; uses limited vapor-carburetion and gets 92 MPG plus reduced pollution.

I’ve picked the more outstanding accomplishments, there’s much more, but it will only bore you.
Kiteman RT-1015 years ago
No, where is your evidence that engineers have got it wrong? Where is your evidence about fuel vaporisation? Where is your evidence that the 92mph car got there through "proper" fuel burning, and not extreme lightness and low friction?
RT-101 (author)  Kiteman5 years ago

Unfortunately, your remarks clearly indicates you haven’t reviewed any of my suggested reading materials. I was fearful of this since some diligent research efforts are required, and I won’t spoon feed you. Forcing down bitter medicine never works without self discovery. With some due diligence, all of your questions would be logically answered. Of course, I’m not talking about simple concepts here, and so some technical homework would be expected on your part. Please do me the courtesy of reading some of this material. I suggest you at least review item-9, which can be found at: and if you have any further questions after reading that site, I’ll be glad to discuss them.

I’m not interested in providing a how to cookbook for casual parties. I want to stimulate good thinkers like yourself with enough information to eventually create a critical mass of informed public. A mass of people to challenge the car industry and big-oil as to why they’re not playing cricket with us, and what they can and should do to make a 100+ MPG car and help the world’s energy crunch.

Take a look at California Congressman D.Lungren, who recognizes the need for a technology stimulus by creating legislation that offers a $1B prize for some creative blokes to make a pure gasoline, non-hybrid car that gets over 100+ MPG;    He recognizes that “Detroit” has too much to loose to make this happen for reasons of global oil partnerships and financial control. Lungren recognizes that the necessary inventiveness will come from mavericks with nothing to loose. While folks like yourself are being convinced that electric cars are our only salvation, nonsense! Figure out how much fuel (oil, coal, or natural gas gets burned to generate electric power) an all electric car really costs to recharge, and we’re not making any headway, particularly in pollution.

Kiteman RT-1015 years ago
He recognizes that “Detroit” has too much to loose to make this happen for reasons of global oil partnerships and financial control.

Oh, dear, now we're on that old conspiracy. Every single associated concern acknowledges that fossil fuels are running out, and need to be both conserved and replaced.

Figure out how much fuel (oil, coal, or natural gas gets burned to generate electric power) an all electric car really costs to recharge, and we’re not making any headway, particularly in pollution.

Absolutely none, if you are selective in your power generation methods. Wind, wave, tidal, deep-ocean current, biomass, hydroelectric, geothermal etc etc etc. can all be used to generate useful amounts of electricity, and thus power cars without using fossil fuels.

There is now only one barrier to mass switch to electric cars, and that is standardisation.

Just like every car manufacturer designs their engines to run off petrol with a particular set of properties - burn-speed etc - if they all sat down and standardised battery properties, petrol stations could become swap-out stations, and recharging your car would be even quicker than topping up the tank.

RT-101 (author)  Kiteman5 years ago

OK so I’ve finally got you thinking forward. Renewable sources of energy definitely needs to grow beyond the drop in the bucket it exists at today and will probably take another decade or two. Meanwhile Detroit can make vapo-cars operational in about two years with the proper political incentives.

Glad to see you got the message about vapo-cars. I hope to see you becoming an advocate of this “old” concept.  BTW I never claimed “vapo” burning originated with me, I’m just improving on its concept with key design features to make it a reality.

The vapo concept is more like 100 and not 50 years old. Your Peel link is irrelevant and misses the point. The Peel car doesn’t qualify on my approval list because while it’s “a nice toy” and gets over 100 MPG, it doesn’t use the “vapo-carburetor” concept and is just an enclosed, glorified motorcycle. Think of it this way; with “vapo” the Peel would get 3X or 354 MPG, or by making it into a “roomy” four passenger four wheel car, as challenged by  ;  ,  it could still get its quoted 118 MPG!

My challenge to you is how would you go about creating an all vapor, 3X car engine? Do you think the 2X Yunick engine, which ran in a “real” 4-seater car and not a toy, was properly designed for vapo-combustion needs? Keep in mind it only got 51 MPG and not our 100+, albeit back in 1981.

1-10 of 38Next »