my 2004 civic obeys new fuel economy law

I routinely get 36 MPG on the highway in my 1997 Civic.... Yes, an 11 year old car is getting 36 MPG! I also get 30 MPG in the city, and my neighbor keeps hounding me to sell the Civic to his son because I have two cars. Since my other car is an impractical gas burning V8 sports car, there is no way I am letting go of the Civic.

Oh, do I ever know that one. In 2000, I had a 2000 model year truck that was no where near what the EPA rating was. I thought to myself, did they measure EPA and throw in a downhill factor or something? I got

11 MPG in the city and 16 MPG on the highway and I think the sticker claimed 14/20... yeah right. I won't even tell you how bad it was when pulling my 3,000 pound mobile DJ trailer around, but it was SINGLE digits and I had an additional $50 to $150 charge if I had to travel out of town!

OTOH, before my 2007 Accord EX-L V6 6MT was totaled this past October, I managed to eek out 31 to 33 MPG on my SEVEN trips from Louisiana to Florida between February and May 2007. I thought that was pretty good for a car that could hit 60 MPH in six seconds flat. Not bad for a 30 MPG highway rating per the sticker. At least my experience with my Hondas is that they were always close to or better than the sticker EPA MPG rating whereas my domestic brand cars never once hit the EPA rating on the sticker.

epa ratings are done on a rolling road - i'm interested to see how they take vehicle weight into account in that scenario, if at all.

It's the EPA ratings that count. Most people don't drive cars in a fuel-efficient manner. And the mileage estimates for almost all cars went down from last model year to this model year, because of changes in the way the cars are tested.

Jeff

Yet, except for the hybrids, no cars meet the standard.

Jeff

That's an *ESTIMATED* mileage based on slower highway speeds than you have traveled. It is also based on E0 fuel (i.e., pure gasoline - most of the available today are oxygenated, which decreases the mileage).

Well, dah! What do you expect? To be able to pull a big trailer around for free?

Gee, my Ford Contour V6 gets about 30 mpg on the highway, same as the sticker estimate.

Jeff

They don't.

Jeff

Just to complicate things further, the CAFE standard is based on

*unadjusted* EPA mileage estimates. The EPA estimates reported to buyers have been adjusted downward for many years to make them more realistic. As you mention, the adjustment was tweaked again (further downward) for 2008. Thus a car rated at 29 mpg might actually be meeting the 35 mpg standard.

Not true. The vehicle weight is factored into the calculation which yields the reported estimate.

Evidence please.

The mileage is determined by the Sec. of Transportation, not the EPA. And there is no standard for determining how the mileage is measured.

Jeff

Jeff

What standard? The "standard" is not specified by law. Rather, the Sec. of Transportation will determine what the standard is (not the EPA).

Jeff

Vehicles are placed in "inertia weight classes" based on their weight in 500 Lb. increments. (Too course in my judgement but that is the way it is.)

(2) A vehicle may be tested in different vehicle configurations by change of vehicle components, as specified in paragraph (b)(1) of this section, or by testing in different inertia weight classes. Also, a single vehicle may be tested under different test conditions, i.e., test weight and/or road load horsepower, to generate fuel economy data representing various situations within a vehicle configuration. For purposes of this part, data generated by a single vehicle tested in various test conditions will be treated as if the data were generated by the testing of multiple vehicles.

Note how in this example from the CFR on how to calculate mpg values, the inertia wieght class and the transmission are all that is needed to determine the CAFE mpg fro a vehicle with a given engine:

Step III. Determine base level fuel economy values.

A. For all the base levels except the base level which includes 4,000 pound, manual four-speed transmission data, the base level fuel economy is as noted in Step II since only one vehicle configuration was tested within each of these base levels.

3,500 lb/M4 transmission 16.1001 mpg. 3,500 lb/A3 transmission 15.9020 mpg. 4,000 lb/A3 transmission 13.8138 mpg. 4,500 lb/A3 transmission 13.2203 mpg. 5,000 lb/A3 transmission 10.6006 mpg.

The test procedure is codified in the Code of Federal Regulations (see above link) which reads in part:

§ 600.111-08 Test procedures.

(a) FTP testing procedures . The test procedures to be followed for conducting the FTP test are those prescribed in §§86.127 through

86.138 of this chapter, as applicable, except as provided for in paragraph (b)(5) of this section. (The evaporative loss portion of the test procedure may be omitted unless specifically required by the Administrator.)

(b) Highway fuel economy testing procedures . (1) The Highway Fuel Economy Dynamometer Procedure (HFET) consists of preconditioning highway driving sequence and a measured highway driving sequence.

(2) The HFET is designated to simulate non-metropolitan driving with an average speed of 48.6 mph and a maximum speed of 60 mph. The cycle is 10.2 miles long with 0.2 stop per mile and consists of warmed-up vehicle operation on a chassis dynamometer through a specified driving cycle. A proportional part of the diluted exhaust emission is collected continuously for subsequent analysis of hydrocarbons, carbon monoxide, carbon dioxide using a constant volume (variable dilution) sampler. Diesel dilute exhaust is continuously analyzed for hydrocarbons using a heated sample line and analyzer. Methanol and formaldehyde samples are collected and individually analyzed for methanol-fueled vehicles (measurement of methanol and formaldehyde may be omitted for 1993 through 1994 model year methanol-fueled vehicles provided a HFID calibrated on methanol is used for measuring HC plus methanol).

(3) Except in cases of component malfunction or failure, all emission control systems installed on or incorporated in a new motor vehicle must be functioning during all procedures in this subpart. The Administrator may authorize maintenance to correct component malfunction or failure.

(4) Transmission . The provisions of §86.128 of this chapter apply for vehicle transmission operation during highway fuel economy testing under this subpart.

(5) Road load power and test weight determination . §86.129 of this chapter applies for determination of road load power and test weight for highway fuel economy testing. The test weight for the testing of a certification vehicle will be that test weight specified by the Administrator under the provisions of part 86 of this chapter. The test weight for a fuel economy data vehicle will be that test weight specified by the Administrator from the test weights covered by that vehicle configuration. The Administrator will base his selection of a test weight on the relative projected sales volumes of the various test weights within the vehicle configuration.

(6) Vehicle preconditioning . The HFET is designed to be performed immediately following the Federal Emission Test Procedure, §§86.127 through 86.138 of this chapter. When conditions allow, the tests should be scheduled in this sequence. In the event the tests cannot be scheduled within three hours of the Federal Emission Test Procedure (including one hour hot soak evaporative loss test, if applicable) the vehicle should be preconditioned as in paragraph (b)(6) (i) or (ii) of this section, as applicable.

(i) If the vehicle has experienced more than three hours of soak (68 °F?86 °F) since the completion of the Federal Emission Test Procedure, or has experienced periods of storage outdoors, or in environments where soak temperature is not controlled to 68 °F?86 °F, the vehicle must be preconditioned by operation on a dynamometer through one cycle of the EPA Urban Dynamometer Driving Schedule, §86.115 of this chapter.

(ii) In unusual circumstances where additional preconditioning is desired by the manufacturer, the provisions of §86.132(a)(3) of this chapter apply.

(7) Highway fuel economy dynamometer procedure . (i) The dynamometer procedure consists of two cycles of the Highway Fuel Economy Driving Schedule (§600.109(b)) separated by 15 seconds of idle. The first cycle of the Highway Fuel Economy Driving Schedule is driven to precondition the test vehicle and the second is driven for the fuel economy measurement.

(ii) The provisions of §86.135 (b), (c), (e), (f), (g), (h) and (i) Dynamometer procedure of this chapter, apply for highway fuel economy testing.

(iii) Only one exhaust sample and one background sample are collected and analyzed for hydrocarbons (except diesel hydrocarbons which are analyzed continuously), carbon monoxide, and carbon dioxide. Methanol and formaldehyde samples (exhaust and dilution air) are collected and analyzed for methanol-fueled vehicles (measurement of methanol and formaldehyde may be omitted for 1993 through 1994 model year methanol-fueled vehicles provided a HFID calibrated on methanol is used for measuring HC plus methanol).

(iv) The fuel economy measurement cycle of the test includes two seconds of idle indexed at the beginning of the second cycle and two seconds of idle indexed at the end of the second cycle.

(8) Engine starting and restarting. (i) If the engine is not running at the initiation of the highway fuel economy test (preconditioning cycle), the start-up procedure must be according to the manufacturer's recommended procedures.

(ii) False starts and stalls during the preconditioning cycle must be treated as in §86.136(d) and (e). If the vehicle stalls during the measurement cycle of the highway fuel economy test, the test is voided, corrective action may be taken according to §86.1834?01 as applicable, and the vehicle may be rescheduled for test. The person taking the corrective action shall report the action so that the test records for the vehicle contain a record of the action.

(9) Dynamometer test run . The following steps must be taken for each test:

(i) Place the drive wheels of the vehicle on the dynamometer. The vehicle may be driven onto the dynamometer.

(ii) Open the vehicle engine compartment cover and position the cooling fan(s) required. Manufacturers may request the use of additional cooling fans for additional engine compartment or under-vehicle cooling and for controlling high tire or brake temperatures during dynamometer operation.

(iii) Preparation of the CVS must be performed before the measurement highway driving cycle.

(iv) Equipment preparation. The provisions of §86.137(b)(3) through (6) of this chapter apply for highway fuel economy test except that only one exhaust sample collection bag and one dilution air sample collection bag need be connected to the sample collection systems.

(v) Operate the vehicle over one Highway Fuel Economy Driving Schedule cycle according to the dynamometer driving schedule specified in §600.109(b).

(vi) When the vehicle reaches zero speed at the end of the preconditioning cycle, the driver has 17 seconds to prepare for the emission measurement cycle of the test.

(vii) Operate the vehicle over one Highway Fuel Economy Driving Schedule cycle according to the dynamometer driving schedule specified in §600.109(b) while sampling the exhaust gas.

(viii) Sampling must begin two seconds before beginning the first acceleration of the fuel economy measurement cycle and must end two seconds after the end of the deceleration to zero. At the end of the deceleration to zero speed, the roll or shaft revolutions must be recorded.

(10) For alcohol-based dual fuel automobiles, the procedures of §600.111(a) and (b) shall be performed for each of the fuels on which the vehicle is designed to operate.

(c) US06 Testing procedures . The test procedures to be followed for conducting the US06 test are those prescribed in §86.159 of this chapter, as applicable.

(d) SC03 testing procedures . The test procedures to be followed for conducting the SC03 test are prescribed in §§86.160 through 161 of this chapter, as applicable.

(e) Cold temperature FTP procedures . The test procedures to be followed for conducting the cold temperature FTP test are generally prescribed in subpart C of part 86 of this chapter, as applicable. For the purpose of fuel economy labeling, diesel vehicles are subject to cold temperature FTP testing, but are not required to measure particulate matter, as described in §86.210?08 of this chapter.

[71 FR 77933, Dec. 27, 2006]

The standard is set by Congress. This was in all the papers:

That is so that the vehicle maker doesn't have to submit several different vehicles that are nearly identical, except for different weights. But, if say a 3000-lb car gets 30 mpg on the highway test, the number isn't adjusted. however, if the vehicle maker has a 3500 car that is nearly identical, there is a formula that can be used to estimate the mileage the 3500-lb car would get based on the mileage the 3000-lb car obtained. So the vehicle maker can test either car and estimate the mileage of the other car or the vehicle maker can test both cars to get the estimates.

I am talking about the new requirements, as seen in the Energy Independence Act of 2007

not the requirements for the 2008 cars. Jeff

I don't think that is exactly the way it works, but in any event, the (approximate) weight of the vehicle is accounted for.

AFAIK, the 2007 legislation changes the CAFE mileage standard that each manufacturer must meet (or pay a fine.) The method of testing has not changed. Do you have a source indicating otherwise?