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Car Forum / Toyota / Toyota Cars / February 2007

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EPA Mileage Question

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Bill Tuthill - 22 Feb 2007 18:59 GMT
I keep hearing that EPA mileage testing changed for 2008 models,
so city/highway MPG numbers will be lower.

Will the CAFE (corporate average fuel economy) standards be lowered
to compensate for new EPA test methods, or does this really amount to
a stealth increase in fuel economy for the USA?
mrv@kluge.net - 22 Feb 2007 23:58 GMT
> I keep hearing that EPA mileage testing changed for 2008 models,
> so city/highway MPG numbers will be lower.
>
> Will the CAFE (corporate average fuel economy) standards be lowered
> to compensate for new EPA test methods, or does this really amount to
> a stealth increase in fuel economy for the USA?

The EPA has set city and highway laboratory tests.

The average of these are used for the CAFE standards.

For the Moroney labels (the window stickers and published numbers from
the manufacturers and fueleconomy.gov), the city and highway test
results are then discounted by some multiplier derived in the early
1980s to more accurately reflect American's driving at that time.

According to:
http://www.fueleconomy.gov/feg/ratings2008.shtml
For the new labels as of the 2008 model year, the EPA is still doing
the old city/highway tests and reporting those, but is also doing
additional tests (to represent faster speeds and acceleration, air
conditioner use, and colder outside temperatures) and will also be
reporting those too.

So, it looks like the city/highway test cycles remain the same, so
CAFE is still based off of those old tests (without any adjustment),
while the published fuel economy numbers will be changing (moving
downward for all vehicles) thanks to adding in 3 new tests.

More info:
http://www.fueleconomy.gov/feg/how_tested.shtml
"How Vehicles are Tested"
http://www.fueleconomy.gov/feg/fe_test_schedules.shtml
"Fuel Economy Tests"
http://www.epa.gov/fueleconomy/420f06062.htm
"EPA's Fuel Economy Programs"
http://www.epa.gov/otaq/fedata.htm
"Fuel Economy Guide Data Files"
by the US EPA

http://www.ewg.org/reports/realMPG/part1.php
"Real MPG: Putting the Truth in Your Tank" by the Environmental
Working Group

http://www.bluewaternetwork.org/reports/rep_ca_global_fuelfalsehood2.pdf
"FUEL ECONOMY FALSEHOODS:  How government misrepresentation of fuel
economy hinders efforts to reduce global warming and US dependence on
foreign oil" by the Bluewater Network, 2002
Mike Hunter - 23 Feb 2007 18:13 GMT
Forget about cars and truck.  According to the latest reports, if we REALLY
want to reduce the so called greenhouse gasses, we need to tell PATA to go
the hell and eat more BEEF.  Either that  or put catalytic converters on
cows a.ses    LOL

mike

>> I keep hearing that EPA mileage testing changed for 2008 models,
>> so city/highway MPG numbers will be lower.
[quoted text clipped - 44 lines]
> economy hinders efforts to reduce global warming and US dependence on
> foreign oil" by the Bluewater Network, 2002
Jeff - 26 Feb 2007 23:09 GMT
> Forget about cars and truck.  According to the latest reports, if we
> REALLY want to reduce the so called greenhouse gasses, we need to tell
> PATA to go the hell and eat more BEEF.  Either that  or put catalytic
> converters on cows a.ses    LOL

Actually, what we need to do is eat less beef and drink less milk (except
for babies who should get their milk from a different source, namely,
mommy).

If we eat less beef and milk, farmers will stop growing these animals.

You have obviously never been near my nephew. I swear you need a catalytic
convertor for his butt, too.

Jeff

Jeff

> mike
>
[quoted text clipped - 46 lines]
>> economy hinders efforts to reduce global warming and US dependence on
>> foreign oil" by the Bluewater Network, 2002
larry moe 'n curly - 23 Feb 2007 09:58 GMT
> I keep hearing that EPA mileage testing changed for 2008 models,
> so city/highway MPG numbers will be lower.

Apparently the numbers on the window stickers and the numbers that
auto makers are required to meet for CAFE standards are different
because the former are arbitrarily adjusted to make them more
"realistic".    I'd rather rely on the Consumer Reports mileage
figures because they seem to be a lot more realistic.

What I don't understand are the new standards for SUVs and trucks.
Instead of making them meet a single average, they have to meet
different standards based on their size group, and this means that
some makers of the worst gas guzzling SUVs won't have to improve the
fuel economy of their vehicles very much, but a company like Subaru,
which makes mostly smaller and more fuel-efficient SUVs, will have to
improve their fuel economy a lot.
Ray O - 23 Feb 2007 17:00 GMT
>> I keep hearing that EPA mileage testing changed for 2008 models,
>> so city/highway MPG numbers will be lower.
[quoted text clipped - 4 lines]
> "realistic".    I'd rather rely on the Consumer Reports mileage
> figures because they seem to be a lot more realistic.

When you say "former," the fuel economy figures posted on the Monroney Label
are not arbitrarily adjusted - they are detemined by EPA fuel economy
measuring standards.

> What I don't understand are the new standards for SUVs and trucks.
> Instead of making them meet a single average, they have to meet
[quoted text clipped - 3 lines]
> which makes mostly smaller and more fuel-efficient SUVs, will have to
> improve their fuel economy a lot.

There is a need and consumer demand for SUV's and trucks, and it is
unrealistic to expect a large vehicle to get the same fuel economy as a
small one.  The new standards do require the larger vehicles to improve fuel
economy, and consumer demand will also encourage the automakers to improve
fuel economy.  For example, while the 15 ~ 16 overall real-world MPG for the
2008 Tundra and Silverado sounds terrible when compared to a 30 MPG Corolla,
it is much better than the 12 ~ 13 MPG that a vehicle with comparable
payload capacity would have gotten even 2 vehicle generations ago.
Signature


Ray O
(correct punctuation to reply)

mrv@kluge.net - 23 Feb 2007 19:40 GMT
On Feb 23, 12:00 pm, "Ray O" <rokigawaATtristarassociatesDOTcom>
wrote:

> >> I keep hearing that EPA mileage testing changed for 2008 models,
> >> so city/highway MPG numbers will be lower.
[quoted text clipped - 8 lines]
> are not arbitrarily adjusted - they are detemined by EPA fuel economy
> measuring standards.

Yes, the same EPA tests are used for the CAFE standards and the
figures used on the Monroney label.

An average of the raw city and highway MPG data is used for the CAFE
standards.

However, for the Monroney label (window sticker and fueleconomy.gov
listing) since the mid-1980s through 2007, the EPA test results are
discounted (lowered) by a multiplier, down 10% for city and 22% for
highway.  Yes, this was to make them more "realistic" to the early
1980s American driver.  The numbers you see listed on the Monroney
label is not the actual results of the EPA tests, but this lowered
number based on the tests.
larry moe 'n curly - 24 Feb 2007 04:36 GMT
> > Apparently the numbers on the window stickers and the numbers that
> > auto makers are required to meet for CAFE standards are different
> > because the former are arbitrarily adjusted to make them more
> > "realistic".

> When you say "former," the fuel economy figures posted on the Monroney Label
> are not arbitrarily adjusted - they are detemined by EPA fuel economy
> measuring standards.

Doesn't the EPA apply an adjustment multiplier that's varied over the
years?

> > What I don't understand are the new standards for SUVs and trucks.
> > Instead of making them meet a single average, they have to meet
[quoted text clipped - 12 lines]
> it is much better than the 12 ~ 13 MPG that a vehicle with comparable
> payload capacity would have gotten even 2 vehicle generations ago.

But by requiring greater improvements for small SUVs, the government
may discourage auto makers from producing them over larger SUVs.  So
like the current loophole that gives manufacturers a second CAFE just
for trucks and SUVs, it could backfire and result in higher, not
lower, gas consumption.
Ray O - 24 Feb 2007 07:41 GMT
>> > Apparently the numbers on the window stickers and the numbers that
>> > auto makers are required to meet for CAFE standards are different
[quoted text clipped - 8 lines]
> Doesn't the EPA apply an adjustment multiplier that's varied over the
> years?

The fuel economy figures listed on the Monroney Labels are the same as in
the fuel economy guides published by the EPA, but the fuel economy figures
themselves are 90% of the measured city and 78% of the measured highway fuel
economy as a correction factor.  There is also a projected sales weighting
among models to accocunt for differences in models.

The way that fuel consumption is measured is IMO a little backwards.
Instead of measuring how much fuel enters the engine, the exhaust passes
through an analyzer and the hydrocarbons in the exhaust are measured.  This
is like someone calculating caloric intake by measuring what comes out in
the bathroom.

CAFE is a more complicated formula, and there are adjustments for vehicle
footprint and production volume.

>> > What I don't understand are the new standards for SUVs and trucks.
>> > Instead of making them meet a single average, they have to meet
[quoted text clipped - 22 lines]
> for trucks and SUVs, it could backfire and result in higher, not
> lower, gas consumption.

Automakers are allowed to choose between the current CAFE calculation method
through 2010 or use a new reformed CAFE calculation method, and they must
use the reformed CAFE starting in 2011.  Under the reformed CAFE standards,
there is a sliding scale based on vehicle footprint.  Because of the
formula, it looks like automakers still have to improve their CAFE
proportionate to the size of the vehicles they produce.  In other words,
there is no penalty or incentive to produce larger or smaller trucks.

The new CAFE rules recognizes the fact that larger vehicles tend to be safer
than smaller vehicles and that economic factors and consumer preferences
tend to influence consumer vehicle choices than CAFE.
Signature


Ray O
(correct punctuation to reply)

Bill Tuthill - 23 Feb 2007 17:15 GMT
Thanks MRV and LMnC!  I also found this news story on NPR.org
showing graphs of the disparity, especially for "light trucks",
between CAFE standards and actual manufactured vehicles.

http://www.npr.org/templates/story/story.php?storyId=7120263

> What I don't understand are the new standards for SUVs and trucks.
> Instead of making them meet a single average, they have to meet
[quoted text clipped - 3 lines]
> which makes mostly smaller and more fuel-efficient SUVs, will have to
> improve their fuel economy a lot.

Then I would be more likely to buy a Subaru!  Currently the RAV-4
gets better gas mileage and has more cargo space.
 
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