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Khosla Ventures Increases Stake in Transonic Combustion; 100 MPG Demonstrator Targeted for Q3 2008

17 January 2008

Khosla Ventures has increased its investment in fuel-injection company Transonic Combustion, Inc. to become the company’s largest preferred shareholder. Transonic is an R&D-phase company developing an advanced fuel injection system for automobiles which promises to dramatically increase fuel efficiency. This fuel injection system allows engines to run on gasoline, diesel and a wide range of bio-renewables.

Transonic says that a unique aspect of its technology is that it can precisely control fuel heat release during the combustion process without using spark ignition or relying on compression ignition.

Although it is holding details on the technology close, Transonic says that the technology achieves ultra-high efficiency by operating conventional gasoline engines at ultra-high compression ratios and incorporates very precise ignition timing and carefully minimized waste heat generation.

A key aspect of the technology is a new type of fuel injector. This injector can be supplemented by advanced thermal management, EGR, electronic valves, and advanced combustion chamber geometries.

Along with operating conventional engines with high efficiency on gasoline, this technology can utilize fuels on the basis of their chemical heat capacity largely independent of their octane or cetane ratings. Economical, highly functional mixtures of renewable plant products can be utilized which are not practical in either spark ignition or conventional compression ignition engines, according to the company.

The 18-month-old company has progressed from single cylinder research to current full size car engine testing. Transonic is in the process of developing a 100 mpg technology demonstrator in a sports car which is targeted to be on the road by the third quarter of 2008.

The company is moving towards commercialization plans and has started to recruit experts in the automotive, combustion science, materials science and ultra-precision manufacturing areas. Recent additions to the Transonic team include:

  • Mike Frick, formerly chief engineer for direct injection systems at Delphi with prior positions as strategic planner and chief engineer for injection systems at Siemens.

  • Dr. Dan Flowers, an advanced combustion researcher from Lawrence Livermore National Laboratory.

  • Dr. Feng Bin, a lubrication and seals expert, from Ford Motor Company and then Visteon, following its spinout from Ford.

With the additional investment, Vinod Khosla has joined the board of directors. Khosla Ventures participated in the first and second rounds of funding, in conjunction with Venrock and Rustic Canyon. The size of the investment was not disclosed, but was at a substantially higher valuation than the Transonic’s second round of funding which closed July 2007.

Transonic was founded by Mike Cheiky, a serial inventor/entrepreneur with expertise in batteries, fuel cells and computer architecture. Cheiky was the founder of Ohio Scientific, Zinc Matrix Power and V-Star.

Transonic’s innovative fuel injection system is an important building block in developing the next generation of fuel-efficient engines. Our commitment to growing Transonic’s business complements our firm’s additional investments in the engine space. Credit should be given to these firms for their work toward developing the 100 mile per gallon car in the coming years.

—Vinod Khosla

Last week, Khosla Ventures announced an investment in EcoMotors, a company that is developing a new family of compact, modular, efficient diesel engines. (Earlier post.)

January 17, 2008 in Engines, Vehicle Systems | Permalink | Comments (30) | TrackBack (0)


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Simply amazing (if not unbelievable) that a start-up can do in 18-24 months what 100+ car/engine manufacturers could not do in 100+ years.

Did cheap oil put them all to sleep for 10+ decades?

Were governments more interested in high fuel revenues from gas guzzlers?

Did Oil interests play a slowdown role?

Does anybody have the answers?

Government gets .33 cents per gallon Tax revenue. Why would they want cars that use less gas

I wish that makers of engines would quote BSFC, not MPG. MPG doesn't mean anything. Honda has a vehicle that gets over 100mpg already, it's called the Metropolitan and it uses a carburator and makes 5 horsepower. BSFC tells you the fuel efficiency PER HORSEPOWER of a motor. It's the only true way to compare fuel efficiency of the drivetrain itself, independant of the type of vehicle it is installed in.

The credentials of the founders appear genuine.

I will reserve the right to take proper professional skepticism, until the developments are significantly further along, however.

Sid, you are right, apples with apples and engines with engines. Examples:
- VW 1 litre,2 persons, 12 hp,100 km/l (240 mpg).
- 2007 Shell Ecomarathon winner, 1 person, 2800 km/l(6650 mpg).
Anybody may be confused with the numbers above, the first is a car for the real world with all the safety requirements, a monocylinder clean diesel, a little slow and expensive (magnesium, composites) but it was ready since 2003. By the way, ¿why we can´t see it in the streets in a "peak oil now" age?
The second is a prototype only for midgets and for a special purpose, 30 km/h max. speed and no more than 50 km total run. It works with a hydrogen fuel cell and it is necessary an extrapolation from calories to compare it in km/l or mpg with regular fuels.
Speaking about engines the standard way to measure specific consumption is in g/kwh for a certain fuel or kcal/kwh for every fuel.

The name transonic implies the technology is a direct injection strategy based on slightly supersonic injection speeds (achieved with Laval jets in the injector tip). Extremely high injection pressures - and hence, parasitic losses, would be required to achieve this. Pressure waves in the fuel system (presumably common rail) would be hard to control, though one German company has suggested using a continuous fuel flow loop that is simply redirected when the injector needle is opened. If the fuel velocity barely ever changes, hydraulic wave amplitudes become very small.

The idea behind transonic injection would be to deliberately induce a knock-type ignition once the trailing sonic boom catches up with the fuel droplets after those are slowed by friction against the highly compressed fresh charge. Ignition would occur in situ, with the flame front dying once it reaches the front of the jet and runs out of fuel. Combustion noise and mechanical stresses could be very high, though they could perhaps be mitigated via multiple small injection events.

If this conjecture is correct, the fuel may have very little opportunity to disperse and evaporate, especially in the relatively small cylinders used for passenger car applications. Initial PM production might be quite high, though subsequent processes might burn most of it off again during the expansion stroke (cp. regular diesel CI).


I agree with you on the point of BSFC. It is a better measure of engine efficiency than MPG. Some of the engines that get the lowest BFSC are modern diesels that run in trains and trucks. Low MPG, but high efficiency (low BSFC).


I agree with you on the point of BSFC. It is a better measure of engine efficiency than MPG. Some of the engines that get the lowest BFSC are modern diesels that run in trains and trucks. Low MPG, but high efficiency (low BSFC).

@ Brian:

"Government gets .33 cents per gallon Tax revenue. Why would they want cars that use less gas"?

Well... if you didn't have to fight wars for oil, your government wouldn't NEED to collect the same amount of tax revenue. Would it now?

Right...we wouldn't need any tax dollars if not for that pesky war because we don't have a failing infrastructure and numerous other problems - right?

They need to RAISE the taxation rates to fix the roads & bridges out there.

BTW - what is the general defense spending budget without the war costs? You don't really think the military up and disappears like magic when the war in Iraq is complete do you?

So if you drive a 400 hp tank that has a good BSFC that makes you greener than a some 20 hp car with a slightly less BSFC. Sounds like BS for chure

Taxes are not paying for the war right now, the costs are added to the defict only.

What is BSFC?


Based on your statements, it seems like transonic combustion is more suitable for a slow speed engine with a large combustion chamber, would the large chamber lose more heat, reducing efficiency?

Is the creation of particulate matter a sign of poor combustion of fuel (incomplete combustion), and a further reduction of efficiency?

Thanks for your help..

Brake specific fuel consumption (BSFC) got it, sorry.

Google: Tucker Movie The Man and His Dream
Gives a few reasons to ponder your belly button
Is it the oil interests? or is it
Follow the Money?
History shows anyone or groups that increases milage more than 19% sells out or pays a price
We already have cars that get 100+ mpg
When the water will kill your gold fish, how about your children, When there is a 300% increase of brain tumors in Europe, people need to prioritize...Go Khosla

100 mpg on a revolutionary injection system alone? Great! Now add it to a PHEV!

We may just get to the 100 mpg level without all the 150 mpg PHEV odd math about a plug in not using gas for the first N many miles. From a cost standpoint the 150 mpg PHEV looks more like 60 mpg to me anyway.

By combining techniques we just might get closer to 100 mpg. I think that would be mind boggling. You have 1 gallon of liquid fuel that can take you and your car 100 miles. Ever try walking 100 miles? Even walking 5 miles is a ways and now you can go 20 times farther using only 1 gallon of liquid fuel.

Sounds like high speed (fequency) multiburst controlled injection as per various previous descriptions. The thermal control may well be ceramic coating of internal surfaces which reflect the heat back to enhance the combustion while at the same time allowing higher peak or instantanious temps , at the same time reducing transfer to cylinders, pistons, block - water - radiator and air coolant losses.
High compresions, so again large savings of those precious calories.
One approach amongst many, beleive it - we are going to see a move from post second world war technology !
Pity its taking another war to shift to second gear!
Moving the nut behind the wheel may take a little longer.

@ Bill W -

it's almost always easier to combust a fuel charge completely in a large cylinder with a slow-moving piston. Heat loss to the coolant is also lower. PM formation is generally a sign of a locally rich mixture (i.e. inefficiency), but sometimes that's unavoidable.

Of course, you should bear in mind that my earlier comment was speculative on what "transonic combustion" actually means. Combustion regimes are complex beasts and don't always behave like an outside observer would intuitively expect them to.

Hopkins - the water doesn't kill your goldfish: stop putting it in a 1 gallon bowl with no filtration, that is killing your goldfish!

There have been many, many such designs over the last 70 years. The most famous was the Pogue carburettor which it seems achieved 200mpg on a Model T Ford in the 1930s. Atomisation and pre-cracking of the fuel achieves much higher fuel efficiency.

We need these systems as retrofittable kits for existing vehicles.

I agree that retrofits would be useful. With all the makes, models and years it would be difficult to provide them for every car. Maybe the most popular ones would be good candidates.

Emphyrio, Snopes covered the Pogue myth better than most. It mentions both that the car makers self interest would trump any alliance with big oil if such a carb was available and it also mentions just how much any politician would love to go down in history as the one who made the US independent of foreign oil.

Combustion efficiency is on the order of 99.9% in a modern engine so there are no gains there. However I think this injector uses super high velocities M>>1 to introduce a detonation to combust the fuel instead of a spark and or compression. This is supposedly able to control the heat release. Since combustion is not controlled by a spark or compression, almost any type of fuel could be used(alcohols,biomass,etc). Again this allows the use of high compression ratios (which increase thermal efficiency) since there is no risk of abnormal combustion, and this is the main selling point for this system.
I would like to see any tech data/SAE paper on this before I make any judgements, but it seems too good to be true...

and if you think you can get 200 mpg with a carbeurator, ive got some ocean front property in mn for sale....

Here's what's going to happen: Transonic will be bought buy one of the major carmakers for some ungodly amount of money. Then it'll disappear off the face of the earth - kind of like the Ark of the Covenant at the end of Raiders of the Lost Ark.

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