EPA - Do they suck or not?

[cawimmer430]

I wonder what Wimmer will say about the S400 hybrid since he bashed the LS460h so hard.

You must have missed the thread where I commented on it. 

[TBR]

I'm totally confused here.

Or is MB doing the usual "underrate" thingy?  

Probably not. The EPA tests are very regimented, IE: accelerate to 50 mph over 15 seconds and maintain that speed for 2 minutes (I made that up as an example), and therefore easy to replicate for anyone with a rolling road (which MB definitely has) and knowledge of that exact regiment (which MB almost certainly has). Meaning that MBs predictions will almost certainly be accurate. This could mean two different things:

1. The EPA numbers are out of sync with real life numbers in this instance. The testing methodology is far from perfect and for some reason hybrids seem to really bring out the faults.

2. German press has been babying the S400 Hybrid for some national pride reason, resulting in better fuel economy numbers than the car would get in the real, real world.

Whatever it is, from what this we can gather that at least in one special set of circumstances (the EPA test) the LS600h does in fact get better gas mileage than the S400 Hybrid.

[ifcar]

Or an Option 3: the European standardized tests are out of sync with real life.


Related note: C/D just did a big article on the EPA mileage process that should be online sometime in the next week.

[the Teuton]

I just read in the SAE magazine that Renault is preparing the world's first diesel hybrid.  All of the Dodge ESX prototypes were diesel hybrids, and they scored upwards of 70 mpg as real family sedans.  Why only almost a decade later are these things finally coming out?

[280Z Turbo]

I just read in the SAE magazine that Renault is preparing the world's first diesel hybrid.  All of the Dodge ESX prototypes were diesel hybrids, and they scored upwards of 70 mpg as real family sedans.  Why only almost a decade later are these things finally coming out?

Big oil is paying them off.

OR...

Cost and reliability concerns. I suppose a compression-ignition engine doesn't work as well as spark ignition with stopping and starting all the time.

[TBR]

Or an Option 3: the European standardized tests are out of sync with real life.


Related note: C/D just did a big article on the EPA mileage process that should be online sometime in the next week.

Oh, I thought Wimmer was talking about real world results achieved by German journalists. I can't say I have been paying much attention to the S400 Hybrid (in fact, I had forgotten it was even coming out until this thread).

[cawimmer430]

Probably not. The EPA tests are very regimented, IE: accelerate to 50 mph over 15 seconds and maintain that speed for 2 minutes (I made that up as an example), and therefore easy to replicate for anyone with a rolling road (which MB definitely has) and knowledge of that exact regiment (which MB almost certainly has). Meaning that MBs predictions will almost certainly be accurate. This could mean two different things:

1. The EPA numbers are out of sync with real life numbers in this instance. The testing methodology is far from perfect and for some reason hybrids seem to really bring out the faults.

2. German press has been babying the S400 Hybrid for some national pride reason, resulting in better fuel economy numbers than the car would get in the real, real world.

Whatever it is, from what this we can gather that at least in one special set of circumstances (the EPA test) the LS600h does in fact get better gas mileage than the S400 Hybrid.

Or an Option 3: the European standardized tests are out of sync with real life.


Related note: C/D just did a big article on the EPA mileage process that should be online sometime in the next week.

Or the different driving conditions here have resulted in better fuel economy. Where does the EPA test their cars? In the city? On a freeway? I assume they test their cars under mixed conditions but I don't think they can always get the same fuel economy given the many factors that can influence results. Drivers, weather, traffic conditions, tire pressure etc.

[ifcar]

Or the different driving conditions here have resulted in better fuel economy. Where does the EPA test their cars? In the city? On a freeway? I assume they test their cars under mixed conditions but I don't think they can always get the same fuel economy given the many factors that can influence results. Drivers, weather, traffic conditions, tire pressure etc.

In a laboratory.

[cawimmer430]

Oh, I thought Wimmer was talking about real world results achieved by German journalists. I can't say I have been paying much attention to the S400 Hybrid (in fact, I had forgotten it was even coming out until this thread).

I think there is a fundamental difference between a European-spec and US-spec car that will always give different results. The LS600h here in Europe is always clocked at around 6.5 seconds 0-100 km/h. 

[S204STi]

Big oil is paying them off.

OR...

Cost and reliability concerns. I suppose a compression-ignition engine doesn't work as well as spark ignition with stopping and starting all the time.

I would assume that the only real hurdle is transparency to the driver.  A diesel at startup is... kinda noticeable.

[565]

Oh, I thought Wimmer was talking about real world results achieved by German journalists. I can't say I have been paying much attention to the S400 Hybrid (in fact, I had forgotten it was even coming out until this thread).

I've been thinking, and I've got a theory on this.  I think it's probably because the LS600H is a more powerful car than the S400.  I think that more powerful and faster accelerating cars have a bit more trouble meeting EPA predicted numbers unless you are really conciously trying to reach them.

EPA has a very strict set of testing parameters, driving at a certain speed, accelerating up to another speed at a certain rate.  All cars whether they are 400hp sports cars or 130hp econoboxes have to follow the exact same routine.  However that doesn't always happen in the real world.  Instead of adjusting our driving so we drive the same exact same speed and accelerate at the exact same rate in every car, we tend to be creatures of habit, we tend to press the accelerator the a similar amount, push the engine to similar RPMS, and naturally the more powerful car will be accelerating a bit faster as we move it through traffic.

For example I have no trouble meeting EPA city for the Pathfinder, but rarely meet EPA city in the Z06.  The only time the Z06 does EPA rating is constant highway cruise. 

Here is a chart of the a large mid size lux comparo from C&D.  Though the difference is small (usually just 1 mpg) it follows the trend I predicted.

http://www.caranddriver.com/var/ezflow_site/storage/original/application/9399bf848a86860da2c573e2374145f1.pdf

The more powerful cars with around 300HP.  Acura RL, A6 4.2, Cady STS V8, M45, Jag S-type 4.2, GS430.  They all managed 1 mpg less than or exactly equal to their city EPA rating during their 600 mile loop.

The two cars with less HP, the BMW 530i, and the E350 both managed to do 1mpg better than their city EPA rating.

[r0tor]

Related note: C/D just did a big article on the EPA mileage process that should be online sometime in the next week.

its a pretty good read

[nickdrinkwater]

The EU standards are quite optimistic in some cases, I would agree with that.

[Klackamas]

They suck.   So do Smartcars.

[Raza]

I've been thinking, and I've got a theory on this.  I think it's probably because the LS600H is a more powerful car than the S400.  I think that more powerful and faster accelerating cars have a bit more trouble meeting EPA predicted numbers unless you are really conciously trying to reach them.

EPA has a very strict set of testing parameters, driving at a certain speed, accelerating up to another speed at a certain rate.  All cars whether they are 400hp sports cars or 130hp econoboxes have to follow the exact same routine.  However that doesn't always happen in the real world.  Instead of adjusting our driving so we drive the same exact same speed and accelerate at the exact same rate in every car, we tend to be creatures of habit, we tend to press the accelerator the a similar amount, push the engine to similar RPMS, and naturally the more powerful car will be accelerating a bit faster as we move it through traffic.

For example I have no trouble meeting EPA city for the Pathfinder, but rarely meet EPA city in the Z06.  The only time the Z06 does EPA rating is constant highway cruise. 

Here is a chart of the a large mid size lux comparo from C&D.  Though the difference is small (usually just 1 mpg) it follows the trend I predicted.

http://www.caranddriver.com/var/ezflow_site/storage/original/application/9399bf848a86860da2c573e2374145f1.pdf

The more powerful cars with around 300HP.  Acura RL, A6 4.2, Cady STS V8, M45, Jag S-type 4.2, GS430.  They all managed 1 mpg less than or exactly equal to their city EPA rating during their 600 mile loop.

The two cars with less HP, the BMW 530i, and the E350 both managed to do 1mpg better than their city EPA rating.

See, I think the area in which I live would yield the opposite results.  Harder acceleration for a longer period of time in a lower powered car would result in lower mileage.  I drove my friend's MkIV Jetta 2.0, and you had to really stand on it to get it up to speed in 45mph zones.  My Jetta can do it faster on 1/4 throttle.  So I'm up to speed and cruising after accelerating more softly against his flooring it for twice the length of time.

[Raza]

They suck.   So do Smartcars.

Yeah, because that wouldn't have happened to any other car.

[2o6]

That looked like it used to be an HHR or Blazer or something.

[Submariner]

That looked like it used to be an HHR or Blazer or something.

I could see how that conclusion could be drawn from a 4 foot by 5 foot cube of scrap metal.

[2o6]

I could see how that conclusion could be drawn from a 4 foot by 5 foot cube of scrap metal.

Call me a nerd, but those are GM wheels.

[Madman]

Call me a nerd, but those are GM wheels.

Nerd.






Cheers,
Madman of the People

[cawimmer430]

MB S400 Hybrid Fuel Economy from Hybridcars

Benz estimates fuel economy for the S400 will be 23 in the city and 33 on the highway. EPA numbers are not yet official, but HybridCars.com did our own mileage test of this big luxury sedan on the roads of Southern Germany. Our drive loop took us from Stuttgart?the home of Mercedes Benz?to the town of Buel and back, a round trip of approximately 150 miles. The route was evenly comprised of high-speed driving on the Autobahn?where we ran at, ahem, greater than 100 mph?as well as moderately paced rural roads, and narrow streets through smaller hamlets. We achieved an impressive 29.3 miles per gallon?not bad for a car that weighs almost 5,000 pounds. (By the way, the V6 of the S400 is plenty strong for the Autobahn.)

With much stricter speed limits in the US, it?s reasonable that fuel economy results will be even better. But saving fuel and money is not the first concern for buyers of this car. The buyer of the S400 hybrid is probably just as interested in pairing the Mercedes three-pointed star emblem with a hybrid badge, to demonstrate a combined interest in luxury, refinement, and green status. Mercedes claims that the S400 is the ?CO2 champion in the luxury class,? emitting a relatively low 186 grams of carbon per kilometer.

As the hybrid version of the Benz flagship S-Class sedan, the S400 is powered by a mild hybrid system with a 3.5-liter V6 gas engine. The hybrid system allows Mercedes to maintain its high-power profile, while using a V6 instead of a V8 or V12. The electric-gas combo provides a total output of 295 horsepower, channeled through a seven-speed automatic transmission. Benz is particularly proud of what it refers to as ?compact? batter technology. Engineers made this hybrid system as well-packaged and light as possible. (Mercedes-Benz was able to fit the entire pack into the same space, at the right-hand base of the windshield, that previously housed the car?s standard lead-acid 12-Volt starter battery.) The S400 weighs only about 120 pounds more than the standard S-Class.

Source: http://jbrlsr.com/?aid=5336108637&bid=3179980&url=http%3A%2F%2Fwww.hybridcars.com%2Fgas-mileage%2Ffirst-drive-mercedes-benz-s400-hybrid-25826.html

[J86]

I could see how that conclusion could be drawn from a 4 foot by 5 foot cube of scrap metal.

[AutobahnSHO]

We achieved an impressive 29.3 miles per gallon—

That IS impressive if they were getting up to 100mph. Anything above 70mph seriously sucks it out of the gastank...

[cawimmer430]

That IS impressive if they were getting up to 100mph. Anything above 70mph seriously sucks it out of the gastank...

I was thinking the same thing. It will be interesting to see how the S400 Hybrid does with other magazines and sources.

I still would go for an S350 CDI or S350. I don't need anything else.

[hotrodalex]

I still would go for an S350 CDI or S350. I don't need anything else.

And claim to be an enthusiast? 

[cawimmer430]

And claim to be an enthusiast? 

I am - a realistic one. What would I do with an S550? Hammer it all the time to experience those 388-horses? An S350 CDI is pretty quick and basically just as comfortable as an S550: they're the exact same car give or take a few options and the different engines of course.