GPM - The MPG Illusion Website

EcoCAR Challenge Results

2011-08-20T13:37:00.000-04:00

USA Today has an interesting summary of a 3-year EcoCAR competition sponsored by the Department of Energy and General Motors. The article says:

The teams focused on design during the first year, when Ohio State University placed first. They emphasized implementing that design in the second year, when Mississippi State University in Starkville, MS.,won top honors.

In this final year, they focused on refinements to make the vehicle 98% consumer acceptable, says DeClark, adding it's nearly impossible to satisfy 100% of consumers. She says the cars won't be commercially produced but there are "many applications for these technologies."

A team from Virginia Tech won. They "started with a GM-donated Saturn Vue and swapped out the engine with one from a 2009 Chevy HHR engine. It then added a battery and electric motor and made other tweaks such as eliminating engine idle."

The team leader for Virginia Tech, Lynn Gantt, is "going to work for GM in Michigan, along with five other team members. "

The 80 MPG achievement is particularly noteworthy because they took existing models and engines and had to achieve a high level of consumer acceptability. That's a sharp contrast with the X-Prize winners that achieve 100 MPG, but in vehicles that are not road ready.

The difference in gallons per 100 miles between 80 and 100 MPG is a quart of gas.

Hypermiling, Hypoconsuming.

2011-08-16T21:46:00.002-04:00

Avoiding jack rabbit starts and coasting into stop signs can greatly improve the MPG your car gets. These are among a long list of hypermiling techniques that, when carefully applied, have enabled attentive drivers to achieve MPG levels that greatly exceed their car's official MPG rating.

What sorts of levels can be achieved?

An Australian couple is driving across the US in an Eco Cruze with the goal of squeezing "2,000 miles from each fill-up of the car’s 12.6-gallon tank. That comes to 158.7 mpg and seems implausible, but if anyone can do it, the Taylors can."

Or consider the performance of "Hypermiling king Wayne Gerdes and NASCAR driver Carl Edwards" who "averaged 81.5 mpg during a three-day run that started Saturday and saw them double the 700-mile range Ford claims for the Fusion Hybrid."

Or, "Our hypermiling friends at Ecomodder.com took home three trophies at the Green Grand Prix, including top honors for an astonishing 99.7 mpg. Darin Cosgrove, who founded the hypermiling site in November, 2007, tells us he used the “pulse and glide” technique “almost exclusively” to achieve that impressive figure during Saturday’s fifth annual event, which celebrates all things fuel-effient and alt-fueled. Four Ecomodders entered the event, held in Watkins Glen, NY."

Check out the large community of hypermilers at ecomodder.com, gassavers.org, and cleanmpg.com. (More on hypermiling at Mother Jones and Wired. These articles also discuss the dangers of coasting, turning off engines at stoplights, etc.)

Let's look at these hypermiling numbers from a GPM perspective. How much gas do these MPG improvements save?

First, let's translate hypermiling to a gas consumption metric. Let's call extreme performance in saving gas "hypoconsuming." Hypermiling and hypoconsuming are simply mathematical conversions of each other that depend on whether gallons of gas are put in the denominator (hypermiling) or numerator (hypoconsuming).

Here are some high (but achievable) levels of MPG and the amount of gas that is consumed over 100 and 1,000 miles:

Improving a car's MPG from 50 to 100 MPG saves 1 gallon over 100 miles.

Improving a car's MPG from 100 to 150 MPG saves .3 gallons over 100 miles.

In contests to achieve the most impressive levels of MPG, hypermiling with highly efficient vehicles yields very large MPG improvements and very high levels of final MPG. But, as hypermiling figures become more impressive, hypoconsuming figures become less impressive. (The improvement from 200 to 250 MPG yields a 12 ounce reduction in gas use over 100 miles.)

Many SUV owners also try to hypermile. They are often criticized by others for the inconsistency (hypocrisy?) of trying to save gas in an inefficient vehicle. MPG invites the reaction, why bother trying to improve a 17 MPG to 24 MPG? If we focused on hypoconsuming instead of hypermiling, however, we'd see the benefits of getting SUVs from 17 to 24 MPG. The improvement saves over a gallon and half over 100 miles.

Would it ever be possible to hold a hypoconsuming contest where the winner would be chosen based on gas saved from the baseline (EPA) MPG?

Update on Heavy Duty Trucks

2011-08-13T14:13:00.000-04:00

Overdriveonline.com has an article summarizing fuel economy standards for heavy duty trucks. Here are some excerpts.

A key takeaway: New trucks are expected to cost $6,220 more because of the rule; total fuel savings over the life of the truck are expected to be $73,000.

Access the full article here.

New emissions rule to drive truck prices higher

The first-ever regulation for truck fuel consumption and greenhouse gas emissions, announced Aug. 9, is expected to cut diesel use by 4 gallons per 100 miles traveled by the time 2018 models are sold. New trucks are expected to cost $6,220 more because of the rule.

President Obama announced the new standard would yield a total fuel savings of $73,000 over a truck’s life. Heavy-duty trucks should expect a 20 percent reduction in fuel consumption and greenhouse gas emissions by model year 2018 under a new Heavy-Duty National Program.

The Owner-Operator Independent Drivers Association criticized the development, saying there are cheaper ways to achieve the same goals. But many organizations applauded the move.
......

Volvo Trucks and Mack Trucks issued generally supportive statements.

“Certainly the regulation will challenge the industry,” said Mack President and CEO Denny Slagle, “but our past success gives us confidence we’ll meet the challenge. Our focus now is on doing so in a way that minimizes any negative consequences for our customers.”

New CAFE targets for 2025

2011-07-20T23:07:00.003-04:00

Aaron Kessler of the Detroit Free Press summarizes a range of perspectives on the 56.2 MPG CAFE standard proposed for 2025.

Some interesting passages:

Proponents of a higher target say dealers' lots won't look much different in 2025 than they do now: from trailer-towing trucks to subcompacts, with only a small percentage of electrics. But innovations under the hood -- from better gas engines to newer hybrid technology -- could save consumers thousands of dollars on gas, offsetting anticipated higher sticker prices.
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The Consumer Federation of America endorsed the 56 m.p.g. target, after its extensive surveys found U.S. consumers wanted more fuel-efficient cars.

Because most buyers pay for a vehicle over time, CF's analysis concluded, consumers save much more on gas costs each month than they would spend on higher car payments for more fuel-efficient vehicles.

David Friedman, deputy director of the Union of Concerned Scientists, agreed. "From the moment they walk off the lot in 2025, they'll be ahead of the game from where they are now," Friedman said. "Every month, they'll see reduced expenses."

An analysis last year by EPA and NHTSA calculated four cost scenarios for 56 m.p.g., and estimated that while the increase in the typical vehicle available in 2025 could be $2,100 to $2,600, a consumer would make all that money back from fuel savings in just two to three years (based on about 15,000 miles driven each year).
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[S]upporters of 56 m.p.g. see pure electric vehicles and plug-ins as a much smaller percentage of the market by 2025. "It's not electrics that are going to get us there," said the Union of Concerned Scientists' Friedman, predicting electrics might reach 5% of the market.
Instead, he said, it would be improvements on conventional gas and diesel engines, as well as more and new hybrids.

The hybrid component -- in a wide spectrum of forms -- could ultimately bring the biggest change. Three of the four EPA and NHTSA scenarios calculated last year for what the 2025 fleet could look like at 56 m.p.g. found plug-in or pure electrics as a blip -- but the penetration of hybrid vehicles ranged from 25%-65%. That doesn't mean a world of Toyota Priuses. Rather, a whole range of new options from stop-start to so-called mild hybrids to more robust electric-gas combinations will enter the automotive bloodstream.

This year, General Motors is unveiling its new Buick LaCrosse and Regal with a feature called eAssist -- a tiny electric motor that boosts the gas engine's mileage. It's a mild hybrid. The driver might not even know it's happening, at least until realizing the full-size LaCrosse is getting 36 m.p.g. on the highway.

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Kessler notes that "The CAFE program also uses what it calls a "harmonic average." That means small improvements in the worst performers can make a bigger difference than large increases in already-efficient vehicles. The SUV going from 15 to 20 m.p.g. could save more fuel -- and count for more in the CAFE system -- than a subcompact going from 50 to 65 m.p.g."

To be specific, the change from 15 to 20 MPG saves three times as much gas as the change from 50 to 65 MPG over a given distance of driving. In a separate post on CAFE standards, Kessler notes that:

4. Miles per gallon? Try gallons per mile. Fuel economy standards flip the traditional m.p.g. measure on its head. They are derived from how many gallons of gas it takes to travel, say, 100 miles. (The EPA uses carbon emitted per mile.)

5. Baby steps by the worst performers count as giant strides. CAFE is based on consumption (gallons per mile), and uses a "harmonic average" -- that means small improvements in large SUVs and sedans make a bigger difference than jumps in vehicles already topping the efficiency mark.

Baby steps by the worst performers count as giant strides because they are giant strides: Small improvements in MPG on the worst performers lead to larger reductions in consumption than large improvement in MPG on the best performers..