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'Extra Urban' "Top Gear" "BMW 318"

Discussion in 'Gen 2 Prius Main Forum' started by bwilson4web, Dec 23, 2008.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    When recently puncturing another "Top Gear" anti-Prius screed, I noticed a curious claim on their web site:
    '"In the extra-urban EC fuel consumption test, a BMW 318d Touring shows exactly the same fuel economy." ​
    Unlike having a formula 1 race car driver alternate between max accelerator and maximum brake, these are numbers generated using the same driving profile. Sure enough, I found a UK web site that lists the Prius and BMW 318:

    • urban MPG / extra urban MPG (combined) - make model
    • 49.6 / 68.9 (60.1) - BMW 318d ES manual
    • 56.5 / 67.3 (65.7) - Prius T4 1.5 VVT-i automatic
    • 39.8 / 64.2 (52.3) - BMW 318d ES automatic
    Once again, Top Gear is neglecting two other numbers, the urban and combined MPG. They also neglected to point out the BMW has a manual versus the Prius automatic transmission. Although I am not an expert in UK fuel prices, in the USA diesel costs more than gasoline. In short, they are lying by omission, which seems to be their usual practice.

    Still this got me wondering so I looked up "extra urban" and found it is the European version of the USA highway MPG. It follows this driving profile:
    [​IMG]
    What is curious is the Prius 42 mph limit on EV mode falls just under the 70 kph line. We know the Prius gets excellent mileage under or above this line but on the line, the mileage suffers a local hit. My testing suggests the transition between these two control laws cause some waste of energy that leads to a local dip in MPG.

    I notice the new Ford hybrid touts being able to travel at a higher speed in EV mode, 47 mph? This will put most of the European "extra urban" travel in an EV control law range. This single change, moving the EV threshold speed up 5 mph will give the Ford hybrid a significant performance boost on the "extra urban" test.

    As for "Top Gear" and their extra urban claim:

    • not an automatic BMW 318
    • diesel is still more expensive in the USA than gasoline
    Bob Wilson
     
  2. JSH

    JSH Senior Member

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    The 318 is different than a 320d. The 318 is a petrol 4 cylinder car while the 320d is a diesel 4 cylinder car.

    318i = 35.8 / 58.9 / 47.9 for the manual (6-Speed)
    318i = 33.2 / 54.3 / 44.1 for the automatic (6-Speed)

    Now neither of those are higher that a Prius so their claim is unfounded or the intern made a typo.

    Some of us also prefer a manual to an automatic so we don't see having an automatic as an asset but rather as a liability.


    Your note on the test cycle is a very valid one and cycles vary from country to country. The very low city speed of the Japanese cycle is why the Prius gets a crazy 100+ mpg rating there.
     
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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  4. Rokeby

    Rokeby Member

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    Bob,

    Re: the graph in your first post.

    I do not understand the relevance of the data shown.

    If I'm reading it correctly, the units of measure for the x-axis is seconds,
    and the values run left to right, from 0 seconds to 400 seconds.

    400 seconds/60 seconds per minute = 6 minutes, 40 seconds. And in that
    brief interval, the car starts at 0 mph, travels at various speeds up to 75
    MPH, and returns to 0 MPH. And the distance traveled is on the order of
    maybe 5 miles.

    This is the entire EC "extra urban" fuel consumption test, and it lasts
    6m+40s? This simulates what, a fast run to town to get beer and
    weinerschnitzel?

    What's the connection to the every day, and day after day, real world?

    Or is that one of your points; the test itself is kinda dumb?
     
  5. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Yes, you pretty well understand it. Don't take my word, use Google and see what you find.
    The primary success of a standard test is it provides an "apples-to-apples" comparison. However, it also lets us understand the strengths and weaknesses of the test applied to any given vehicle.

    You'll notice my signature shows 52 MPG. I pretty much plateaued at that value after analysis of the EPA test protocol. I simply eliminated the inefficient modes and studied my vehicle and systems to minimize the less efficient modes. I'm simply following a modified EPA protocol but tuned to eliminate or minimize the bad bits. <grins>

    Bob Wilson
     
  6. benway

    benway New Member

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    for some reason clarkson et al [al being the UK motoring press] have taken an extreme dislike to the prius

    clarkson insists on calling it a PRY-US.

    this kind of rant is typical for him, he has a pathological dislike of all kinds of vehicles-- which can be very amusing when he vents

    top gear is entertaining, not objective

    its a very different scenario than in the US. there are few Prius on the road in the UK. I think around half of all new cars are diesels.

    diesel used to be cheaper than petrol, but is now much more expensive, [around 12p/18c litre more] approx 50p/70c gallon]
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I was wondering if Europeans tend to do more 'trip' driving versus commuting compared to USA drivers?

    USA average miles per year are closer to 15,000/year although some have claimed as low as 13,000/year. I'm wondering if similar numbers exist for UK and European drivers?

     
  8. Ogo

    Ogo Prius Owner since 2008

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    Top Gear guys are bunch of populist idiots. It is nice to watch and laugh show, but that's it. No one should base their decisions based on Top Gear idiot opinions. They are very, very biased and have a history of being that since start.
     
  9. hill

    hill High Fiber Member

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    When the EPA re-worked its calc's the Prius changed from 50mpg-60mpg to down in the 40mpg's. The Prius didn't change. Those of us who got 50mpg/60mpg still got it. Those that did better or worse still did the same. Only the test changed. I'd be curious to find out if the BMW mpg test is the same as the one they subjected the Prius to.

    Then there's reliability. Not all the world rates mpg as the end all beat all. Consumer Reports often gives thumbs down to BMW 3 series. "Fun to drive" to me, means it'll be running, now that I've outrown hard cornering & burning rubber. Here's another forum's rating on the 3 series:

    BMW 3 - reliability rating -- An used car - TÃœV reports
     
  10. ronhowell

    ronhowell Active Member

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    All you have to do is Google "Jeremy Clarkson" and read the litany of complaints, errors and plain biased commentary he is accused of to get a handle on this guy. As a fellow Brit, but an American by choice, I know the type well. They have an almost total immunity to consideration of other peoples opinions, and relish the thought of pissing others off with snide, smarmy and fatuous comments, especially if they get a laugh from the great uninformed and unwashed multitude, which they usually do. The car tests are done at Dunsfold Park, an old airstrip originally built by the Canadian Army during WW2.

    He is a motoring version of Rush Limbaugh, in a different neighborhood.
     
  11. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I went to the "Top Gear" web site that discusses the Prius vs BMW M3 and posted this note (limit is 500 characters) :
    Bob Wilson