By on August 25, 2014


The wildly optimistic fuel economy figures touted by auto makers in Europe could be in for a major revamp, as the EU looks to change the way these tests are conducted.

Although new, slightly more stringent standards take effect next month would force auto makers to do things like conduct real road tests, rather than in a laboratory.

According to Reuters, new test standard is being ironed out by VDA, a lobby group for German auto makers, as a counter to a possible new standard by the EU. European OEMs are still agnonizing over tough new CO2 standards, and is eager to preempt even tougher future emissions standards, as well as new fuel economy testing that would cause a major drop in advertised fuel economy and CO2 standards. New rules would also target NOx emissions, which have been linked to lung cancer, and are emitted more frequently by diesel engined vehicles.

Despite this, OEMs acknowledge that the current testing methods are flawed. Many observers have long maintained that European fuel economy figures are overly optimistic and not reflective of real world driving conditions.

Get the latest TTAC e-Newsletter!

27 Comments on “EU Fuel Economy, Emissions Testing Facing Major Overhaul...”

  • avatar
    Big Al from Oz

    I read an article in Rueters the other day regarding the proposed changes in the EU for the testing of FE.

    It is supposed to reflect real driving conditions, to the point of vehicles actually driving on the roads. Plus the EU will also keep their existing emissions and FE targets.

    From what the article stated some auto manufacturers don’t like this.

    Imagine if other countries did this. Boy you would see some dramatic changes to the ‘advertised’ FE of vehicles.

    One that comes to mind is the Pentastar powered Ram, many owners are getting between 16-17mpg average, a bit lower than the claimed FE.

    Diesels will be less affected. Diesels tend to reach or even exceed their FE figures.

    I would like to know what will occur with GDI particulates. A GDI engine emits far more particulates than any modern diesel.

    • 0 avatar
      Athos Nobile

      A diesel runs lean… most of the time. Petrol runs stoichiometric… most of the time. There’s also the energy & fluid density factor that gives it some advantage (I don’t remember the details).

      I recently drove a diesel (first ever) and was surprised at how efficient it was (for a car that heavy).

      GDI will eventually get their PF… like the diesels.

      The EU cycle is optimistic. The EPA cycle is more reflective of how a car is actually driven.

      • 0 avatar

        A diesel can run clean but not as reliably clean as a gasoline engine with O2 sensors. Black diesel smoke is too much fuel and there is no sensor system to control fuel injection based on exhaust. EGR and DPF are emission after ignition fixes. Honda claims a diesel auto engine that controls emissions with a cat. If true it would be a major breakthrough eliminating a troublesome EGR and annoying DPF system.

        • 0 avatar

          Diesel Oxidation Catalysts were already being widely used in the last decade before Selective Catalyst Reduction injection systems became widespread. DOCs don’t really address the problems with soot (DPF) or NOx (SCR) though.

          • 0 avatar

            Navistar oxidation catalyst engines 3 years ago, Class 8 trucks, were an expensive catastrophic failure. If oxidation catalysts were widely used diesel engines why would Cummins and DD use a complex and expensive to buy EGR and DPF system?

          • 0 avatar

            Ford used DOCs on the last gen Diesel Super Duty trucks with the Navistar engines and the Ford 6.7L diesel uses them to this day. That’s pretty widespread.

            As to why they’re used when they also have EGR and DPF, they control different emissions (HCs) as I already alluded to.

            They aren’t problematic in those vehicles and usually only get replaced because of an upstream failure.

          • 0 avatar

            Ford went to Ford diesel engines 2010.
            Then to the 6.7 with a complex Selective Catalytic Reduction and DPF. Eliminates the EGR system. Doesn’t appear that EPA standards can be met with only a simple cat.

          • 0 avatar

            Ford went to the 6.7L for the 2011 MY and use EGR, DOC, SCR and DPF to control emissions.

          • 0 avatar

            “Ford went to the 6.7L for the 2011 MY and use EGR, DOC, SCR and DPF to control emissions.”
            Thanks for the correction. Does clearly point out that diesel engines are not simple, reliable and energy efficient. They have been regulated into complex, unreliable and costly engines outclassed by current gasoline engines for auto use. For class 8 trucks the trend is dual diesel and LNG/CNG but the original emissions controls are required.

          • 0 avatar

            >Does clearly point out that diesel engines are not simple, reliable and energy efficient. They have been regulated into complex, unreliable and costly engines outclassed by current gasoline engines for auto use.

            Definitely. Since Tier II emissions they’ve gotten exceedingly complex and expensive to maintain. Public awareness of this fact when it comes to light duty diesels hasn’t quite caught up yet and many owners are shocked when they buy a modern diesel with the thought that the ownership experience will be similar to that of equivalent 90’s models but quieter operation and more power.

          • 0 avatar

            Certain DOC catalyst materials can affect the ratio of NO2 to NO, which can be an advantage for the performance of a downstream SCR or NOx trap catalyst. This is why systems are usually DOC-DPF or DOC-DPF-SCR (with some variations; DOC-SCR, DOC-SCR-DPF, etc.)

            To RogerB34’s point about the Navistar engines, the DOC wasn’t their problem.

    • 0 avatar

      “To RogerB34′s point about the Navistar engines, the DOC wasn’t their problem.”
      What was their problem?

  • avatar

    Any background to this: “The wildly optimistic fuel economy figures”?
    how is it tested, how overly optimistic? how does it compare to EPA cycle?

    without that information this article is just a statement…

    BTW, with all my cars I had in Europe I met or exceeded advertised numbers. Same with EPA numbers in USA. Even the old EU numbers (before they took into account AC etc.) I met them with all my cars. So I’m a bit skeptical with that general statement the numbers would be flawed. But i see how people drive te their cars: driving gears all the way to 5K rpm, accelerating right before a stop… and then they wonder they use more fuel?

    • 0 avatar

      Any time I read CAR or Top Gear Magazine, I often see vehicles advertised as getting 50 IMPG and in real world getting 30 IMPG, for example. It’s pretty bad, and seems to be simply accepted amongst all publications.

  • avatar
    Athos Nobile

    And I guess that while they’re at that, they’ll also fix the CO2 based taxing systems accordingly.


  • avatar

    “Many observers have long maintained that European fuel economy figures are overly optimistic and not reflective of real world driving conditions.”

    A large part of the “Magic Euro Diesel” phenomenon is down to the disparity between testing cycles. It’s not only diesels, either: when, say, the Toyota Prius is rated at 60-70mpg on the Euro cycle but 45 by the EPA, something is awry.

  • avatar

    If they haven’t switched their gallons to 4.79L yet, that’ll bring down.

    • 0 avatar

      Will not be switching to Gallons of any stripe, they use metric

      • 0 avatar

        Like Derek’s photo above displaying mpg, UK’s Autoexpress and Whatcar record fuel consumption in mpg. I was wondering if Imperial gallons were still used.

        • 0 avatar

          Brits still use imperial gallons when referring to fuel economy in their car magazines and advertising, but the fuel is now sold by the liter…er, litre.

          They also continue to use miles on their road signs (although unlike Americans, they use yards instead of feet.)

  • avatar

    The EPA test is actually pretty conservative. Drive with a light right foot and you can match or exceed EPA testing numbers.

    The problems with the NEDC are many. For one, there are multiple tests based on whether or not your car has enough power to perform the actual highway test… for another… the acceleration phases are incredibly, unrealistically loooooong. Not even hypermilers accelerate that slowly!
    (41 seconds to 70 km/h… yeah… that’s right…)

    And lastly… the NEDC gives a free pass to plug-ins. Since it’s not designed to measure plug-in electrical consumption, it ignores it. Completely. Which is why Porsche can claim nearly 100 mpg with the 918 hybrid.

    The EPA takes everything into account… even converts electric miles into MPGe for easy consumption. Nothing hidden. Nothing left out. The only problems with the EPA arise when manufacturers fudge coastdown testing numbers or are allowed to apply blanket testing numbers across multiple platforms with the same powerplant.

    Those are tiny sins compared to the absolute boondoggle that is the NEDC. Even Japan’s typically optimistic JC08 is miles better.

    • 0 avatar

      I’ve gotten BETTER than the EPA-rated MPG on my car, and that was on the interstate at 78 MPH, with a solid-but-slightly-outdated 3-speed-plus-overdrive auto that does best at 65 MPH.

      Of course, that may be just as attributable to my engine’s “square” HP/TQ ratings (200/200) that keep it from downshifting as much on long grades.

      • 0 avatar

        I typically exceed highway by a lot… but I tend to drive at 50 mph, which is the median speed on our local highways (min 40 mph, max 62 mph).

        I got around 50 mpg out of the Sentra 1.8 on the highway the whole month we had it.

        When I did drive at 60 – 65, I was getting around 45 – 46 mpg.

  • avatar

    I’ve tended to do slightly better in my car, 2014 Escape with the 2.5 litre, than my roommate in hers, 2013 Fusion with the 2.5 litre. The weight is near enough to make no difference, but the aerodynamics are pretty different.

    I think mine is rated higher on the freeway, while hers is rated higher in the city.

  • avatar

    They seem to be changing rules in the middle of the race. They put up very tough fuel economy/emission standards based on a certain test cycle, and now they want to toughen up the test cycle without easing up on the standards. Sort of like requiring a runner to go under 10 seconds in the 100 meter dash on a course that is slightly downhill, and then as they get close to achieving the goal changing the course to uphill.

  • avatar

    My understanding of the background behind this is the strong link between FE and Co2 Output, something the EU has decided to attempt to reduce.
    The disconnect between the test and the real world means that CO2 output from vehicles is higher than predicted.
    The other part to this is the impact the coastdown load has on the FE and emission test result. So to get a optimal result, many manufacturers head to Idiada test facility in Spain, allegedly one of the smoothest test tracks in the world, and wait for the afternoon breeze to record a “real world” (cough cough) coastdown result to plug into the vehicle dyne test.
    I read that Diesel vehicles on the EU test cycle are more likely to be hit harder with this proposed change as it will have a larger incremental affect (especially VW).

  • avatar

    Leave it to the Corporatists to first use government CO2 standards to cajole people out pf perfectly functional gas cars into expensive new diesel ones. Then, once eveyone’s in a diesel, change the standard to push them into ditching those for a gasser again……

    All in the name of childrens’ lungs (and global competitiveness…) or whatever..

    Only upside is, perhaps once everyone has been suckered into squandering their savings on some dull turbo appliance, “science” will discover that the Standard European Lung prefers emissions from nice, proper, high revving NA engines again; and sanity will finally have been restored…

Read all comments

Back to TopLeave a Reply

You must be logged in to post a comment.

Recent Comments

  • namesakeone: I was just wondering: On vehicles with bumper-mounted license plates (all full-sized pickups, among...
  • namesakeone: How far does a can of bedliner spray squirt accurately? From what I see, most of those cameras are...
  • Master Baiter: The Plaid is typical Tesla: Some amazing drive train technology marred by poor ergonomics, like the...
  • golden2husky: DenverMike: Good point about incarceration. I was on a jury a few years ago and the way the cops were...
  • golden2husky: Alcohol ok for the heart? There are plenty of studies showing alcohol consumption causes irreparable...

New Car Research

Get a Free Dealer Quote

Who We Are

  • Adam Tonge
  • Bozi Tatarevic
  • Corey Lewis
  • Mark Baruth
  • Ronnie Schreiber