Diesel Drivers Report Higher Fuel Economy Than EPA Rating; Hybrid Lower

WASHINGTON, DC -- Diesel-powered vehicles deliver more real-world miles per gallon than the numbers on new-car window stickers currently indicate, according to the U.S. Environmental Protection Agency's "YourMPG" database. The findings were detailed in EPA's "Final Technical Supporting Document" accompanying the agency's new fuel economy labeling rule released Tuesday.

The "YourMPG" data, compiled by the Oak Ridge National Laboratory, includes 221 diesel drivers measuring their own fuel economy and providing their real-world MPG to an Internet database. EPA then compared this real- world data with the projected fuel economy calculations it requires for all new cars.

"As can be seen, diesels appear to perform the best with respect to their label fuel economy, outperforming the label by 4.3%," the EPA technical support document said. Diesel was the only power source to see an increase in real-world MPG. Gasoline cars decreased by between 1.4%-1.7%, while hybrid owners saw their real-world mileage drop by over 8% compared to the current fuel economy label.

The link provides complete information about the new EPA test that will on average drop car fuel economy 12% in the city and 8% on the highway.
Read Article

chewy - 12/14/2006 11:40:41 PM

+1 Boost

Here is a link to the EPA press release

http://www.fourtitude.com/news/publish/Industry_Tuner_News/article_2774.shtml

DieselRules - 12/15/2006 1:37:38 AM

+5 Boost

Sorry, but that can only happen in city driving with heavy stop-and-go action. If you are a courier in a city, then a hybrid is good. But if you drive for extended distances, the diesel will out-perform. Plus, the extra baggage of the hybrid drive system and batteries will put it at a disadvantage compared to a plain gas car.

The ONLY time a hybrid has an advantage is when you step on the brake pedal and it captures some energy that would otherwise be turned to heat by the brakes.
Driving on the interstate with cruise-control on, the greater efficiency of a diesel (remember that efficiency is proportional to compression ratio, and diesels are in the 16:1 to 19:1 range compared to your gas-car/hybrid's 9:1 ratio) cannot be matched by anything with a gas engine (all else equal).

NOTE: I run ultra-high performance Yokohama tires on my car. If you don't have to slow down for the corners then your mileage goes up. Works for all cars, not just diesels :)

The Prius' greatest advantage is the 1950's "spaceship" aero body.
If I wanted an ultra-high mileage car, I would buy a Prius, rip out the gas engine, generator, and battery-pack, and install a VW PD 2.0 engine. I'd get 60+ MPG on the highway, and I'd smoke almost any V6 car off the lights, because the alloy Prius without batteries and generators weighs next to nothing! :)

Rupert - 12/15/2006 9:28:35 AM

+3 Boost

mayeb toyota should do that, but then that would prove tha hybrid's aren't as efficient as thought.

jeffy210 - 12/15/2006 10:27:58 AM

+3 Boost

To add to DieselRules, here's a case in point: My drive to work is about 20 miles one way, almost 18 of that is on a highway. Will a hybrid prove efficient for me? No. However a diesel will give me a serious boost over anything. It all depends on what the individual's driving conditions are.

chewy - 12/15/2006 1:19:51 AM

+1 Boost

Really, we will find out.

chewy - 12/15/2006 1:35:01 AM

+1 Boost

http://www.autonews.com/apps/pbcs.dll/article?AID=/20060605/FREE/60601044/1111

VW Jetta: 49.9 MPG observed, 42 EPA (running on B-20 biodiesel as well, extra bonus points)
Toyota Prius: 42 MPG observed, 51 EPA
Honda Accord Hybrid: 33.9 MPG observe, 34 EPA

DieselRules - 12/15/2006 1:41:04 AM

+1 Boost

VW Jetta: 49.9 MPG observed ... that's with plain dinosaur diesel too.
Switch to a blend of Biodiesel, get OVER 50 MPG, reduce emissions, extend the life of the engine, and save the planet!
Just 5% Bio will do it.

DieselRules - 12/15/2006 1:44:34 AM

+1 Boost

Oops! just read that its already on Bio.
One of my engineers has a Golf with the 1.9 PD TDI.
On a camping trip to Yellowstone park he let his pseudo-wife drive for a day. On that tank of gas he registered 69 MPG (Canadian Gallon: 20% larger than a US gallon). That's through hills (my Beetle gets better mileage in hills than on the flat ... can't figure that one out) and with 2 people plus camping gear, cooler, food & ice, ...

dumpsty - 12/15/2006 10:31:54 AM

+1 Boost

Aren't diesel-electric hybrids being tested by Toyota? I can imagine a d-e hybrid doing extremely well against anything on the road today. Can you see a V8 d-e powertrain in a European luxury and near-luxury cars, trucks, and SUVs?

Rupert - 12/15/2006 3:07:25 PM

+2 Boost

citroen now have that system when the car stops the engine's off on the c2 and c3. it's an option.

Cynical - 12/15/2006 6:34:17 PM

+4 Boost

Relating to Fabian 555 - Hybrid vehicles will most likely not come in a manual transmission, given that electric motors typically do not require gears (spin speeds range from 0 to 1500 I think) and the gas motor is extremely small and only requires the minimal hp to keep the vehicle moving against friction (such as on the highway).

1970toyotamarc - 12/15/2006 4:30:57 PM

+1 Boost

"The Diesel Technology Forum is a non-profit organization DEDICATED TO PROMOTING clean diesel technologies. Forum members include engine and vehicle manufacturers, diesel fuel refiners, and manufacturers of emissions control devices. For more information about the Forum, visit our web site at www.dieselforum.org." (emphasis added)

That was the last line in the article. You guys will believe anything. Always look for the source.

chewy - 12/15/2006 8:11:41 PM

+1 Boost

Yes, the EPA is the source. This is according to the EPA's OWN data:

"according to the U.S. Environmental Protection Agency's "YourMPG" database. The findings were detailed in EPA's "Final Technical Supporting Document" accompanying the agency's new fuel economy labeling rule released Tuesday."

Doesn't get any more official than this. Sorry, no bias here.

1970toyotamarc - 12/16/2006 10:47:31 AM

-2 Boost

the EPA is not the source, the EPA is reporting a "fact" gathering report from an outside source, a source committed to promoting diesel technology. Next, the EPA "data" is culled into a report by another diesel suppporting group. Y'all really need to learn to read with a critical eye.

chewy - 12/15/2006 8:13:41 PM

+1 Boost

I see a lack of hybrid fans in here. I guess the truth is too much to handle for them.

chewy - 12/16/2006 5:49:53 PM

+1 Boost

Once again, the source is the EPA. Read the article excerpt. Still not a single hybrid fan that has defended the truth. Oh wait, they can't.

chewy - 12/17/2006 2:15:24 AM

+3 Boost

Nope, diesels with same displacement usaully average about 25-35% less fuel used. VW will soon combine best of both worlds with CCS engines.

chewy - 12/18/2006 4:11:11 AM

+1 Boost

LIAR. The MB E320 gets 36 MPG on the higway. The Lexus GS hybrid only 28. Trust me, when the common rail Jetta TDI arrives next year, it will have awesome performance and amazing fuel economy.

DieselRules - 12/21/2006 12:59:27 AM

+1 Boost

"Germans always like to put up a smaller displacement diesel" against a gas engine, because they are comparing apples-to-apples "performance-wise" and the smaller diesel matches the larger gas engine in real-world driving.
(and please don't compare ANY Benz with a little tin-can Accord. The accord is a pretty car with nice handling, but I wouldn't want to be T-Boned by an SUV in any small or mid-size Japanese model)

DieselRules - 12/21/2006 1:02:53 AM

+1 Boost

Acceleration depends on who drives it. If they nail the accelerator to the floor (like most bone-headed reviewers who have no concept of driving a Turbo-car) then they will SLOW the acceleration.
Its hard to comprehend, but you don't get the best performance from an injected/turbo car by driving it like a vintage 4-barrel V8!