Modified Hybrids Get 250 Mpg

Would it be possible to have mpg in liters/100 km as is used in European data? Of course it´s up to you if you want to be anglocentric in your coverage.
Mile per gallon is to me about as intuitive as the exchange rate of pesos to the yen. I´m sure you could make a nifty little spreadsheet to do the calcualations, heck I could do it for ya!

I have my doubts about the 250mpg claim. Mr. Gremban, the owner of the modded Prius, has pictures of the extra batteries in the trunk. Considering the disclaimers that he put on the 80mpg figure, I'm inclined to believe him.

Where's the proof of a hybrid getting 250mpg? What were the operating conditions of the vehicle? Did it travel on the highway or was it limited to low city speeds? This is nothing but hearsay at present.

Great article, and a great idea. Do the mpg figures that you quote factor in the electricity to recharge the batteries? No, it's not gasoline, but it is energy, and for comparison purposes, it's helpful to have overall energy consumption.

Google does unit conversions wonderfully. The spam filter here doesn't want me to post a link, but typing '250 mpg in liters/100km' in the search field gets the correct result without stress

I find sverrir's comment about litres/100km vs miles per gallon as a method of measurement. In canada we went metric many years ago and I get Celsius and metres, but have never been able to wrap my brain around litres/100KM- we were brought up on Milespergallon and we want to know how far our car will go on a tank of gas, and we tend to think that bigger numbers are better than smaller ones. I would understand kilometres/litre much more than I do the other way around.

However I agree that Treehugger is international and we should include both measurements in our posts.

Thanks for the tip on using google Red, didn´t know they had that feature so worked out.

That's silly - by that logic, a prius with an EV switch (locks to electric only mode) gets infinity miles to the gallon. Plug-in vehicles are not zero emission unless you charge solely from a solar/wind tap. They simply move the emissions to the oil and coal plants that provide that electricity.

"Do the mpg figures that you quote factor in the electricity to recharge the batteries? No, it's not gasoline, but it is energy, and for comparison purposes, it's helpful to have overall energy consumption."

I'll take a stab at it.

Apparently, the Prius uses 0.262 kWh/mile in all-electric mode. Since about 2/3 of grid electricity is lost in conversion and transmission, this translates to 0.786 kWh/mile of primary energy.

Next, to compare gasoline to electricity, we can use BTU conversions -- 3,412 BTU/kWh and 124,000 BTU/gallon of gasoline.

So, to go a mile, the Prius needs 2,682 BTU, or the equivalent of 0.022 gallons of gasoline. This translates into about 46 MPG, or a little less than what the EPA rating is for the Prius using gasoline. Obviously if there is less conversion and/or transmission loss (eg, using distributed renewables at home), this MPG equivalent can be up to almost 120 MPG.

I believe the 250 MPG and similar mileage claims are simply based on how much gasoline is actually used per mile of travel, such that if it's propelled mostly by electricity, very little gasoline is used to power the internal combustion engine per mile.

As for fuels used to create electricity (c. 2004), nationally it's about 70% from fossil fuels (50 coal, 18 natural gas, 3 petroleum), 20% from nukes, 7% from hydro, and about 0.7% from solar, wind, and geothermal. Three percent comes from other sources like wood, waster, other gases, etc.

Of course, this fuel mix is going to vary considerably based on where you live. I assume proponents of plug-in hybrids conceive of vehicles plugging in to distributed renewable systems (like home solar or wind), or at least using grid power that's "green" (like Xcel's Windsource program). In those cases, the emissions and waste effects of the electricity consumption will be totally different from simply sourcing from the average grid power.

Perhaps someone else can share with us a comparison of emissions and waste of a Prius burning gasoline and getting 55 MPG versus 147,500 BTUs of source energy based on the aforementioned grid mix.

With respect to conversions between fuel economy metrics, here they are:

1 MPG = 0.425 km/L = 2.352 L/km = 235.215 L/100 km

So, for the Prius' EPA rating of 55 MPG, it is the same as:
23.3 km/L
4.28 L/100 km

For 250 MPG, that is the same as:
106.3 km/L
0.94 L/100 km

Thanks for taking the time to do the math, Joseph. Interesting stuff.

I wish that Honda would bring over a wider variety of their scooter options, like the classic Super Cub 50, which has a clean four-stroke engine and gets a whopping 343 MPG, and goes for $1,700.
http://www.honda.co.jp/motor-lineup/supercub/index.html

Of course, my favorite is the 99 MPG, two-stroke Gyro Canopy, which goes for $3,900.
http://www.honda.co.jp/motor-lineup/gyro-canopy/index.html

Of course, the eGo is a nice 370 MPG-equivalent option for only $1,200. Too bad it's only seasonal for a climate like the upper midwest.
http://www.egovehicles.com/

We appreciate all the thoughtful comments. I urge you to read our 3-page Fact Sheet, found in PDF form at http://www.priusplus.org and in text form at http://groups.yahoo.com/group/calcars-news

For a quick response to that big issue: why an electric car is cleaner than a gasoline car even on the dirty national (50% coal) grid see section 4 of http://www.calcars.org/vehicles.html

And to keep things lively, we've added a link to this blog at http://www.calcars.org/kudos.html

-- by Felix Kramer, founder, California Cars Initiative

http://www.calcars.org and the PRIUS+ campaign http://www.priusplus.org

I speak for all who read these threads with a concern for science, economics and the truth. Anyone with a solid science background knows that a passenger sedan getting 250 miles PER GALLON OF GASOLINE is not real. Yet look at the headline of this thread. Unfortunately, a depressing percentage of our population lacks the basic science to grasp this. Who knows how they perceive this story? When I hear our policy makers talking about it in speeches, I shudder because they control billions of dollars in resources.

Dr. Kramer, I believe there is potential merit in the concept of plug-in hybrids. For certain consumers, it could make sense to have a short city commute car that will never be stranded on the occasional long trip.

But I ask you this- does a headline or a door panel sticker proclaiming 125 to 250 MPG or more serve the long term goal of spreading this technology? I commend your attempt to speak in some new standard, whether it is KWh or dollars/mile, but so far it is not catching on.

When I see these headlines, I remember things like cold fusion, or the blacklight power guy, or more recently the fuel cell stories, where they run on water, and what comes out of the tail pipe? Water.

I am curious about who makes up the headlines for plug-in hybrid cars. Who allows these headlines, which on the face are a lie, to happen? The Economist did a recent article on EnergyCS proclaiming some absurd MPG, never directly challenging the fact that over half of those miles didn't come from gallons of gasoline.

What happens when you are interviewed? I'm asking because I don't know. Do you push the hype? Does the hype just happen? Or do you point these things out to the media, and they ignore you, resulting in "Modified Hybrid gets 250 MPG!"

Energy Guy

No takers? Come on, you guys.