Natural Gas Series Hybrids

If you look at the drive towards “LCFS” fuel (LCFS means “lower carbon fuel standards”), it appears that natural gas powered vehicles are the wave of the future. Can you say “natural gas powered series hybrid”?

The GM “Flextreme,” set for production in Europe, is the only
series hybrid employing an onboard diesel we’ve ever heard of.
As for a natural gas powered series hybrid, who knows…

Read this recent email from someone on the ground, responding to EcoWorld’s feature “The Case for the Series Hybrid,” published a few years ago:

After reading your article today (even though it’s two years old), I have some points to make. These points are for everyone else promoting electric/hybrid cars.

First, I don’t think the majority of CO2 are from cars. They represent only 40% of fossil fuel use.

Second point is the serial hybrid seems like a no brainer that took GM too many years to figure out (Chevy Volt). A diesel is the best choice for efficiency for obvious reasons but the car makers still haven’t figured that one out. [GM is launching the 'Flextreme' in Europe, which is a diesel series hybrid] Why bother with those big car makers when someone else can do it better? Why does the Navy use diesel-electric submarines?

Third, you, like so many others, never mention natural gas. It is the cleanest fuel yet. Fork lift trucks use them all the time with changeable fuel tanks.

My fourth point is commercial use. Being a commercial vehicle driver, I deal with diesel engines which the average driver doesn’t really think about, but what kind of hybrid can you make with one of those? They have payloads up to 100,000 pounds (garbage trucks). A typical class 7 or 8 truck uses about 50 to 100 gallons per week. Multiply that by 52 and you can get an idea of a year’s use for one truck. Then multiply that by 4 million trucks and buses on the road. 80-90% of everthing you see is brought by trucks. There is a saying in the trucking industry, without trucks, America stops. Somebody better call GE!

Number five is buildings. They also use fossil fuels. Why doesn’t anyone mention that? The more efficiently a building is insulated, the less it costs to maintain its temperature. Oil is used to make foam insulation, yet we still use fiberglass. Foam, mainly polyurathane as well as styrene, is more dense than fiberglass and can be sprayed in place. Polyurathane is a thermoset plastic, which means it is used once. Why not insulate our homes with this foam insulation and then use some of these other alternative technologies to heat and cool? Add PV and you have a much more efficient building.

I just want to expand someone’s view on this alternative fuel thing.

The engine in my brother’s ML450 siezed up because of having no oil. Perhaps I can use that vehicle as prototype if he still has it. The whole engine and transmission would have to be pulled out. The truck weighs about 4k lbs. Can this hybrid technology handle trucks in that weight range? Any tips?

Sir, you have great insights. Respect.

6 Responses to “Natural Gas Series Hybrids”
  1. The Flextreme looks like an incredible ride. For those of us based in the US, we will have to survive with the sporty Chevy Volt!

    Check out videos, news and pics of the Volt at http:/

  2. thomac C gray says:

    That fellow writing emails really should actually get some facts before sounding off about motives of GM, etc. If he had, he would realize that 1) a diesel range extender (or any kind of range extender engine) in a serial hybrid (not series) like the Volt with a 40 mile electric range won’t get much action, and thus it isn’t critical that every last drop be squeezed from the liquid fuel – the gasoline Volt range extender gets 50MPG, the diesel Flextreme about 10-15% more. In the scheme of things, that’s trivial. 2) GM clearly gave the reason for a European and not a US diesel range extender, another public fact obviously missed by this “informed blogger” whose views Ecoworld is pumping – the fact is that diesel engines in Europe do not have to be nearly as pollution free as those in the US, and it would have cost several thousand dollars extra to go diesel in the US, as silly trade off.

  3. kerrry bethune says:

    I note another fact this Ecoworld sponsored blogger obviously missed – if a series hybrid (actually they are serial hybrids) is such an obvious technology, how come GM was the only company to realize this fact of the two dozen automakers around the world? The fact that GM will have a serial hybrid to market long before 90% of the others tells me that if GM is slow, the other automakers must be dead. I also note that without the advent of modern li ion batteries, electric propulsion is limited to 10 MPH runs for quarter mile. That ain’t going to solve nothin. You can’t invent something unlesss you have all the parts available.

  4. troy matson says:

    It’s astounding how ignorant this blogger really is. He obviously is ignorant of the reason GM avoided serial hybrid technology – they were working within the bounds of the California Zero Emission laws, in which a serial hybrid was not considered a zero emission vehicle. This shows just how destructive the zero emission laws really were. In trying to bring a totally emission free vehicle to market, California screwed up the technology completely – another instance of stupid politicians and an even dumber public who half believed that Detroit was “hiding” some terrific new technology. California’s. Thus California’s paranoia
    led to the crappy EVs of the 1990′s (the EV-1, Toyota Rav4 electric, and Honda EV electric). California filmaker Chris Paine then managed to convince the more gullible elements of our society (and most of the media) that GM had “killed” the electric car, when, in fact, GM had offered the car for lease for 10 times longer than Honda before Honda cancelled their EV program. How do you explain “dumb.”? Do these morons really believe that the world was waiting for a car that couldn’t handle round trips to destinations a mere 40 miles away, took 8 hours to “refuel”, had a five year battery pack that cost over $20,000, making it the most expensive ride per mile on the planet, and cost over $40,000 just to build one copy? How do you explain “dumb”?

  5. Ed Ring says:

    Kerry; Troy: I think the fact that natural gas might become a fuel of choice for the series hybrid is a keen insight – hence the email made it into one of our posts. Take it easy on our commenters – we often publish unsolicited emails we receive – we aren’t “sponsoring” anyone. Having said that – your comment, Troy, regarding California’s failure to tolerate a series hybrid, is absolutely correct. Many environmentalists (and misguided policymakers) have fought the series hybrid design for years – apparently unwilling to acknowledge that such a technology would eliminate gasoline consumption for virtually all commuter transportation miles, yet permit deployment of a practical, affordable, long range vehicle. What were they thinking? By the way, Volvo has now also announced a series hybrid – anybody got some information on that? And new entrants Aptera and Fisker are also designing series hybrids.

  6. G Mitchell says:

    I think all youse guys are missing facts. While the originator of the article is wrong on facts: “majority of CO2 is not from” autos, natural gas commercial availability, navy using “diesel-electic” powerplants to power their subs (what is this WWII), building insulation using oil. Tom posting that diesel engines have to be cleaner in the U.S. European Class five diesels emit less than their U.S. gasoline counterparts (

    Compare with ( clearly US vehicles are more polluting. As well as Troy who forgets his econ 101 class: when you make 1,000 of a vehicle, such as the EV-1, the components will cost more as if you would produce a 1,000,000. Notwithstanding, development and production of such an electric vehicle would have been groundbreaking and insured American dominance in the high fuel economy segment of the marketplace worldwide. Instead, Europeans and Japanese are eating our lunch. EV-1′s were getting about 150 Miles per charge (

    All in all many wrong conclusions. However, what’s clear is that we need to have substitute vehicles that are efficient and dependable. Electricity meets those needs whether in pure or hybrid form (series or parallel). I would suggest a common platform wherein batteries and control electronics could be placed and a variety of engines (diesel, gasoiline or true flexfuel engines (that includes natural gas)) could be used to fuel a vehicle and let the market provide a cheap fuel. As we all know with substitute fuels the prices will drop if 25% ran on diesel and 10% ran on CNG and 50% ran on gasoline and 15% other prices would drop since supply would rise all else being equal. Come on people do some research before you write.


Leave a Reply

You must be logged in to post a comment.