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View Full Version : The road to more accurate mileage.


xcel
11-19-2006, 04:00 PM
New rules for calculating estimates take effect next month and will be seen on 2008 models; however, don't look for precise numbers. (http://www.chicagotribune.com/business/chi-0611170151nov17,1,6490068.story)

http://www.cleanmpg.com/photos/data/501/2006_Honda_Civic_Hybrid.jpgRick Popely - Chicago Tribune - Nov. 17, 2006

Since the federal government began estimating the fuel economy of new vehicles 33 years ago, it's been careful to note that actual mileage may vary.

And how, say motorists who don't get the mileage that appears on the window sticker.

The U.S. Environmental Protection Agency hopes to curb such complaints in early December when it announces new rules for calculating its estimates. They'll be rolled out beginning on 2008 model year cars.

Though the new procedures are expected to reduce the estimates from 5 percent to 25 percent, the agency's boilerplate warning will still apply: Your mileage will vary.

"We are very confident these new values will be more reflective of the real world, but how you drive is still the more important factor," said Margo Oge, director of the EPA's transportation and air quality division. "They should always be viewed as estimates. We don't want consumers to view them as absolute values."

Dave Warnke of West Bend, Wis., can attest to that. He averages 52 miles per gallon from his Toyota Prius, while his wife gets 42 from a Prius.

Warnke, however, is not complaining.

"It all depends on how you drive it, and whether you get the engine up to full operating temperature," said Warnke, an electrical engineer who was attracted by the Prius' technology more than the mileage.

His 85-mile round-trip commute to the south side of Milwaukee is mostly on freeways, where he zips along at 55 to 65 m.p.h.

His wife drives less than six miles to and from work, and Warnke thinks that's not far enough for the gas engine to get fully warm, when it operates more efficiently. His wife's Prius tops 50 m.p.g. on the freeway.

"The EPA is a set testing condition that allows some comparisons. After that, you're on your own," he said.

Under the new rules as proposed in January, the city rating for the Prius, currently 60 m.p.g., could drop to around 45 on the 2008 model. The Honda Civic Hybrid's city rating, now 49, could fall to about 38. Highway estimates for hybrids will fall roughly the same as conventional models, 5-15 percent. City estimates for conventional models are expected to decline 10-20 percent.

The final testing criteria from the EPA may not lead to changes that drastic, but the changes will be the first since 1985, when the EPA reduced city mileage estimates by 10 percent and highway estimates by 22 percent to bring them closer to what consumers said they were getting.

Some observers say an overhaul of the EPA estimates is long overdue. Auto and travel organization AAA and Consumer Reports magazine, for example, conduct their own fuel-economy tests and find the current ratings wanting.

The Automobile Club of Southern California, a branch of AAA that operates a test facility, measured on-road mileage in 41 vehicles last year and found that 36 experienced worse mileage than the EPA estimates--on average, 4 m.p.g. less.

AAA then measured mileage the way the EPA does, running city and highway driving simulations in a laboratory. But AAA included three EPA emissions tests that reflect more aggressive acceleration, running the air conditioner and starting a cold engine in sub-freezing temperatures, all of which hurt mileage.

The results came within 1 m.p.g. of the mileage AAA actually recorded.

"With the old test, it was almost impossible to get the EPA ratings," said Steve Mazor, manager of AAA's auto research center in Diamond Bar, Calif. "The [new] test is more accurate and a much better predictor of the mileage people will get."

The EPA will incorporate the AAA tests and add other factors in coming up with the new fuel economy estimates.

"It reflects the way people drive today," Mazor said of the more demanding regimen.

Consumer Reports, which measures mileage on a test track and public roads, said that of 303 vehicles it has tested over six years, only 29 equaled or exceeded the EPA estimates. In city driving, vehicles it tested typically get much less than the EPA numbers.

"The EPA city cycle is fairly gentle, much more gentle compared to how most people drive today," said David Champion, automotive testing director for Consumer Reports. "City driving today has more aggressive acceleration and more braking than the EPA test."

In addition, because the tests are conducted indoors under controlled conditions, automakers can optimize the vehicles to perform well in the EPA's driving cycles, Champion said. That is especially true with hybrids, which may run primarily on battery power in the EPA test but use the gas engine more in the real world.

According to the EPA estimates, hybrids get better mileage in the city because that is where they use electric power. However, most hybrids tested by Consumer Reports and AAA didn't come close to those estimates, either.

Consumer Reports got 35 m.p.g. in the city with a Prius rated at 60 and 50 on the highway (versus the EPA's 51). AAA tested six Prius models, and their mileage ranged from 37 to 50 in combined city and highway driving.

Consumer Reports got only 26 m.p.g. in city driving from a 2003 Honda Civic Hybrid rated at 48 by the EPA. AAA tested two 2004 Civic Hybrids, and one got 36 and the other 49 overall.

"Hybrids still get better mileage than other vehicles," AAA's Mazor said. "It's just not as good as people expect."

Toyota and Honda, the two largest sellers of hybrid models, say they don't expect the lower fuel economy ratings to hurt sales.

Toyota spokeswoman Ming-Jou Chen said consumers buy the Prius for its technology, low emissions and styling. "With a Prius, people know you're driving a hybrid and that it is part of an image that you're environmentally conscious."

Besides, John German, Honda's manager of environmental and energy analyses, said: "Hybrids will drop a little more, but all the vehicles will come down. The relative impact stays the same. We have no problem with that."

Honda, however, worries that the new procedures will overemphasize aggressive driving and extreme conditions, such as the one that runs the air conditioner in 95-degree heat after the car has sat in the sun for 10 minutes. The EPA has not said how much weight it will give those factors.

Chuck
11-20-2006, 08:39 AM
It will be interesting how this will be explained on www.fueleconomy.gov (http://www.fueleconomy.gov). They can't retest back to the 1980's but if they had educated guesses of models back five years, that might help.

It was mentioned on An Inconvient Truth, the US had the lowest FE standards in the industrialized world. I accept the US does not seriously promote FE like other nations, but is it possible the EPA standards are the world's strictest? Don't know about the EU, but Japanese standards are really inflated against American driving. For instance, the Japanese estimate for the next Prius is over 100mpg, but it will likely be in the 60's for the EPA estimate.

xcel
11-20-2006, 10:58 AM
Hi Chuck:

___I was hoping to hear more commentary on this one as it will effect all of us here at CleanMPG. Back in 85, the EPA calculated in the 10 and 22% negative offset for the city/highway ratings in order to try and match what the real world was receiving. It was still too optimistic. If you look at the 1985 and prior FE figures still posted at Fueleconomy.gov, the EPA simply left the older models ratings as is. I am not sure we should do that or not? I can see the Prius II and HCH-II being retested but the Insight will be left as is given it is no longer available for purchase today? That would leave someone like Randall at an expert rating for a seriously long time whereas he would easily be an elite driver with the new regs. And with the new ratings, the Prius II is supposed to have an EPA rating closer to that of 44 mpg’s vs. 55. Do we change the 04 - 07 Prius II specs to match that of the 08’s and beyond? What about Dennis Coyne, Carl Hurschik, and Dan Kroushl in their Prius II’s? Steve, Laurie, and Tom in their HCH-I’s? Tarabell and company in their II’s? Debbie and Rich in their FEH’s? What about the Tim, Psy, Phil, and myself in our Accord’s and Civic’s? The Accord w/ Auto nailed down an abysmal 16 mpg in the CR’s city test and 38 on the highway for a straight up combined 27 vs. the EPA 50/50 combined of 29. This could get ugly for all of us here but more then likely, we will leave the numbers as the ratings imposed in the year in which a particular model was tested/rated and the newer drivers are going to receive a huge benefit in terms of a much easier time to hypermiler status or above. There will be some in the 08/09 rated vehicles that will approach 200% of the EPA combined vs. 150 + % as is the case using today’s ratings in fact!

___Another consequence of this will be the Hybrid premium vs. the non-hybrid’s. Let us guess that the HCH-I would have been pulled down to ~ 36 mpg (CR’s pulled a 26 city/45 highway) vs. the 7th gen Civic at ~ 30.5 (CR’s pulled a 20 city/41 highway). The delta of only 5 mpg’s is not nearly as easy to swallow as the 15 mpg’s that the current EPA estimates allow. There would not have been a single HCH-I sold at that small a delta! The HCH-II allowed a combined of just 37 mpg’s in the CR’s testing vs. 31 for the 8th gen 2006 Civic w/ a stick. Again, would the public spend an additional $2 - $6K depending on trim for just 6 mpg’s worth of FE?

___The fallout from this might actually destroy the Hybrid marketplace as the hybrid premium will be looked upon as so far out of whack vs. $’s of gasoline saved in the everyday consumers eyes. We all know better but if the new EPA regs follows a regiment similar to CR’s, it will turn the hybrid market upside down overnight.

___In terms of the Prius II in the EU, it rates as follows:

56.5 mpg Urban (city) using UK gallons or 47.1 mpg US
67.3 extra urban (Highway) on UK gallons or 56.1 mpg US
65.7 combined on UK gallons or 54.75 mpg US.

___The Japan 10/15 rates her at the following:

35.5 km/l or 33.0 km/l depending on options (Highway) or 77.6 mpg US
2.8l/100 km (City) or 84 MPG US.

___Good Luck

___Wayne

Chuck
11-20-2006, 11:13 AM
I never considered that this would cause the DB at www.cleanmpg.com (http://www.cleanmpg.com) to be overhauled - Tom can't like this. :eek:

Not sure that the new EPA formula will hurt hybrid sales yet. Every vehicle is going to take a hit on estimated FE.

antrey
11-20-2006, 11:16 AM
I feel a good solution would be to increase the %over EPA required to achieve hypermiler/expert/elite status for drivers with 2008 and newer model vehicles.

xcel
11-20-2006, 11:20 AM
Hi Antrey:

___Another great idea … I hope I can remember this thread and your suggestion when the 08 and beyond automobiles w/ the newer and lower EPA ratings are hitting the market place.

___Good Luck

___Wayne

Chuck
11-20-2006, 11:33 AM
I second Antrey's idea.

Over the long haul, gas prices will rise and the economics will motivate drivers to seek better FE.

If the new EPA for a Prius is 45mpg, it might be reasonable to see a 12mpg vehicle be relisted at 10 or even 9! As long as the estimate annual cost is there, I don't think the hybrid savings will be slighted.

xcel
11-20-2006, 12:09 PM
Hi Chuck:

___It will be great to see the large Trucks and SUV’s getting their due. Take a look at last years SUV ratings from CR’s.

Rank|Model tested|CR Overall mpg|City mpg|Highway mpg|150-mile trip mpg
|Midsized and Large SUV’s||||
1| Honda Pilot EX|19|13|27|23
2|Acura MDX|18|12|27|22
3|Lexus RX300*|18|13|23|22
4|Toyota Highlander Limited (V6)|18|12|24|22
5|Nissan Pathfinder LE|16|11|22|19
6|Ford Explorer XLT (V6)|16|11|23|20
7|Jeep Grand Cherokee Laredo (6-cyl.)| 16|10|23|20
8|Buick Rendezvous CXL|16|11|24|21
9|BMW X5 4.4i|15|10|20|18
10|Mercedes-Benz ML500|15|11|20|18
11|GMC Envoy SLE (V6)|15|10|22|19
12|Toyota Sequoia Limited|15|11|20|19
13|Toyota Land Cruiser|14|9|20|18
14|Dodge Durango SLT Plus|13|8|20|16
15|Chevrolet Suburban 1500 LT|13|9|18|17
16|Chevrolet Tahoe LT|13|9|19|17
17|Ford Expedition Eddie Bauer|12|8|18|15
18|Ford Excursion XLT|10|6|13|12

___But the Hybrids will be also compared to their non-hybrid counterparts. As can be seen with the 8th gen Civic vs. the HCH-II CR’s numbers, the hybrid will have some huge headwinds to go up against.

___Let us assume you and I were Joe Q. Public. Would you purchase an 07 HCH-II w/ an MSRP of $23.2 - $24.9K (w/ NAVI) that is estimated at just 37 MPG’s or the Civic EX w/ a stick at $19.3/$20.1K (MT/Auto) - $21.1/$21.9K (MT/Auto – both w/ NAVI) at 31 MPG’s? Remember the EX comes with a far more powerful motor, nicer looking wheels, and a sunroof for $3 - 4K $’s less outlay. The HCH-II does not stand a chance even with the tax credit if the new EPA calculated numbers are anywhere near where CR’s says they are. You and I know better as to what the std. Civic and HCH-II are worth but the public will look at the delta and say to themselves, is Honda crazy?

___This is why I believe it could turn the hybrid market upside down. The TCH was rated at 34 combined according to CR’s vs. the EPA’s 39 which is a lot closer then one would have expected so the TCH should not be hurt nearly as much. I will find the 07 Camry’s CR numbers for you later on.

___Good Luck

___Wayne

Fenrir
11-20-2006, 12:50 PM
I have a spreadsheet somewhere that shows EPA vs CR mileage estimates for quite a few late model vehicles. I calculated what percentage of the EPA estimates the CR estimates represented. I don't remember the numbers (note to self: try to find that spreadsheet...) but the hybrids (The Insight, Civic Hybrid and Prius II I belive were the 3 hybrids on the list) did better than average. When you look at the mpg disparity, getting 51mpg in an Insight rated to get 65 looks a lot worse than getting 9mpg in a Canyon Arrow rated to get 12. But it is the same percent difference (roughly).

What I want to know is- what will the new calculations do to fleet averages? Japanese auto makers have little to fear. But will Detroit have to scramble to really meet that 27.5mpg that they can barely meet with inflated numbers? Will their attempt to knock hybrids off their high horse backfire in a big way?

I love the fact that car makers are touting their fuel economy now, but I hate it when commercials say "The X gets Y miles per gallon" or "such-and-such-car has blah mpg" like the number is determined entirely by the design of the car! I wonder if this wording will change when more vehicles have single digit mileage estimates.

Chuck
11-20-2006, 12:53 PM
Fenrir,

Is that a MIMA mod on your stick shift?

Fenrir
11-20-2006, 01:18 PM
"...or are you happy to see me?" ;)

Yes, those are my MIMA controls. When I figure out how to add images, you'll get a better look.

http://www.cleanmpg.com/photos/data/522/sa550048-sm.jpg

brick
11-20-2006, 01:28 PM
I don't understand how CR gets some of their numbers. I looked at their rating for my car, which is 15mpg city/ 34mpg highway / 23mpg overall. That standard puts me within a stone's throw of Elite even when counting the 9 months I "just drove it."

I think the simplest thing for our database is probably to figure out some kind of correction factor to generate adjusted estimates for the older vehicles, and just use the new numbers as they come in from the EPA. It wouldn't be perfect but it would be closer to putting everybody on the same baseline. Depending on the extent of the change, we might then consider re-calibrating the Expert and Elite categories to be more in line with what we know to be the true capabilities of some drivers. It's that or add a fourth category like "cyborg" at the 175%+ level.

psyshack
11-20-2006, 01:30 PM
I have a feeling the hybrids, suv's, and pickup's are going to take a beating.

The Civic's, Corolla's, Camry's, Accord type cars are going to do real well IMO.

st_judas
07-03-2008, 12:58 PM
I feel like moving the bar for hypermiling is somewhat disingenuous. Those of us who have been at it all along could be glad for a more accurate rating, and for a new challenge. Changing the established definition just to maintain (y)our ranking seems to go against the whole purpose of having a community of people who try to get good FE. Then again, the bar was moved for us, by the EPA. I think anyone who beats the EPA should be welcomed to the fold. Anyone who achieves the far more lofty rank of 125% can feel like they've accomplished something, but hypermiling is not about TITLES or RANK.

lightfoot
07-03-2008, 04:43 PM
What happens to the ratings here concerns me less than the perpetuation of the perception that the car gets the mileage it gets, the driver has nothing to do with it. The original intention of the EPA ratings was that they would be simply a way to compare vehicles' FE by testing them identically under controlled lab conditions. This has been corrupted into using them as a prediction of what mileage you can expect. And completely loses any sense of driver involvement.

It would be far more useful to have both an EPA lab test number (with some attempt as matching normal driving conditions city and highway) matched with the number someone can get by using some standardized HM methods. DIfferent vehicles have different HM potential, so this would be helpful.

EPA would never do it, but how about publishing some max possible MPG estimates here to help car shoppers?

It motivates me tremendously to see other Insight drivers doing better than me because it shows me there is room for me to improve. Don't know if this is the same for others, but I'm sure glad you guys above me in the logs are there.



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