EPA Revises MPG Test, Mileage Estimates to Drop

Road&Track/The Daily Auto Insider ^ | December 13, 2006

[sully777]

The Environmental Protection Agency (EPA) issued new testing procedures that will cause fuel economy estimates on the stickers of new vehicles to drop an average of 12% for city driving on most 2008 model year vehicles, and 8% for highway driving, the Associated Press reported.

The changes are in response to consumer complaints that fuel economy estimates often don't match real-world driving. The EPA's new procedure will take into account data from vehicle tests designed to more accurately assess high-speed driving, rapid acceleration, the use of air conditioning and driving in cold temperatures, the story said.

Highly fuel-efficient vehicles are expected to see the largest slide, with ratings for city driving dropping by as much as 30% and highway estimates falling 25% from current levels. Mileage estimates for gas-electric hybrids probably will be 20% to 30% lower for city driving and 10% to 20% lower on the highway, the EPA said.

"The EPA's new fuel economy sticker ensures American motorists won't be stuck with higher-than-anticipated charges at the pump," said EPA Administrator Stephen L. Johnson in a statement.

[sully777]

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Final Rule: Fuel Economy Labeling of Motor Vehicles: Revisions to Improve Calculation of Fuel Economy Estimates. (Signed December 11, 2006)

The city and highway miles per gallon (MPG) estimates help consumers compare the fuel economy of different vehicles when shopping for new cars. Although no single test can ever account for the wide variety of conditions experienced by every driver, the estimates determined using the new methods will more accurately reflect today's driving conditions.

To more clearly convey fuel economy information to consumers, EPA has also revised  the fuel economy window sticker that appears on new vehicles beginning with 2008 models manufactured after September 1, 2007.

[sully777]

"...Mileage estimates for gas-electric hybrids probably will be 20% to 30% lower for city driving and 10% to 20% lower on the highway, the EPA said. "

[sully777]

Also, the EPA will revise MPG Estimates downward by 2011 including medium-duty and heavy duty trucks and SUVs

[sully777]

Automotive Ping List

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[fireforeffect]

Odd, I have always gotten BETTER mileage than the window sticker. My city mileage usually equals the posted highway mileage and I have a lead foot.

Of course, being a maintenance fanatic helps.

[Disambiguator]

Do you run your tires at a higher pressure than the mfr suggestions?

[fireforeffect]

Of course. I'm not stupid.

[Disambiguator]

I'm not saying you're stupid, I was just asking!

That is probably a major contributing factor to your results.

[backbencher]

[...consumer complaints that fuel economy estimates often don't match real-world driving.]

OFTEN! More like NEVER!

[sully777]

A confusing mishmash of government double-speak seems to indicate that the EPA's "real world testing estimates" will soon be used by the DOT for "forthcoming revisions" in the CAFE standards. It sounds like a backdoor way to pass a law without the approval of any elected officials. Any revisions in the CAFE standards will increase gas guzzler taxes...isn't that convenient.

BTW, I typically drive 65 mph in mixed driving and my mileage is spot on with the Honda window sticker. What is interesting is that my mileage drops like a stone when the EPA mandated fuel formulas come through the fuel pipeline for summer and winter.

[JamesP81]

Odd, I have always gotten BETTER mileage than the window sticker. My city mileage usually equals the posted highway mileage and I have a lead foot.

I've noticed this as well. I've talked to a guy who has a C5 Corvette manual transmission that gets almost 30 mpg on the highway. Of course, that goes out the window if you put your foot on it, but if you're just cruising it's not hard on the fuel tank. I guess the fact that the engine generates so much torque that it can cruise at interstate speeds with the engine running not much above idle helps out there.

[thackney]

What is interesting is that my mileage drops like a stone when the EPA mandated fuel formulas come through the fuel pipeline for summer and winter.

There is only summer requirements from June 1-September 15 and winter requirements from September 16-May 31. There is no "in-between" fuel.

Chevron, EPA requirements

[bkepley]

>Mileage estimates for gas-electric hybrids probably will be 20% to 30% lower<

Now they tell me.

[sully777]

I have talked to many drivers that monitor their fuel economy for business and they all agree that their mileage drops at least 10-20% for about two weeks corresponding to the time fuel formulas for summer and winter take effect.

I talked to local Honda service managers and they have found many complain about sudden loss of mpgs by customers at the corresponding times...

After the formulas come online, my mileage will return to normal.

BTW, I've monitored all mpgs on every tank since 1995 and this strange phenom has never altered.

[chiller]

Since I moved out of the left lane, back down to the speed limit my mileage tracks closely with advertised estimates. Savings are at least 15% ...closer to 20%

[sully777]

Sorry to tell you that your mileage will also drop in cold weather, with excessive highway use, or if you use the A/C.

[bkepley]

>Since I moved out of the left lane, back down to the speed limit my mileage tracks closely with advertised estimates. Savings are at least 15% ...closer to 20%<

The big problem is I bought it mostly for my fiancee to use and her average drive one way is about 3 miles. They just don't do much for you unless you drive long distances at slower speeds.

[thackney]

Interesting, thanks for the clarification. I misunderstood your previous statement. I do not know what would cause a temporary drop. I hope someone else can provide some more information.

[sully777]

Since I moved out of the left lane, back down to the speed limit my mileage tracks closely with advertised estimates. Savings are at least 15% ...closer to 20%

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My FIL was trying to drive from Texas to Oklahoma at 58 mph. Dear MIL put up with it for the first 200 miles but lost her patience and told him to floor it or she'll take over. She needed them to keep up with the flow of traffic in the slow lane. He was so dismayed because he was getting 28 mpg on his V-8. He was like a beaten man when he reported only 22 mpg because of "lead foot"! She retorted that she would have driven 80 mph had she been at the wheel...she said she ain't getting any younger and waiting for slowpoke to make it home would have cost her precious time in their fleeting lives.

LOL funny loving couple about to celebrate their 50th anniversary.

[Dilbert56]

My brother's in-laws are in the automotive industry and said there's some good news in this. Since the EPA tested at 55MPH, the manufacturers tuned their engines for 55MPH (so they'd get the highest possible number on the sticker). Of course few of us dive at 55MPH so we were driving at speeds for which our engines weren't tuned. This should realign the manufacturers' efforts with our real lives.