• Mar 23rd 2008 at 12:02PM
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Readers of London's Sunday Times kept telling the auto reporters that the official mileage numbers for the Prius were overstated by about 15 imperial mpg. Intrigued, the Times decided to test things out by running a Prius against a BMW 520d with regenerative braking from London to Geneva, a 460-mile trip. Then they added 100 miles of urban running to give the Prius a chance to recover ground on its proper turf.

The verdict: the conventional diesel with Efficient Dynamics beat the full hybrid by 2.2 imperial mpg, or 1.8 US mpg. This means that an executive sedan with all the mod-cons and 500 extra pounds beat the mollusk-shaped sip-tastic wunderkind known as the Prius. And the diesel's CO2 emissions are just 32 g/km higher than the hybrid poster-child, to boot.

Admittedly, we find the test a bit unfair -- the Prius is not meant show its muscle at "75-mph into a headwind," and adding 100 miles of urban driving doesn't make up for 460 miles of autoroute. Reverse those driving conditions and then let's see who won. Still, for all of us diesel fans out there, it's a feather we won't mind putting in the cap. Thanks for the tip, George!

[Source: Sunday Times via Technoride]

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    • 1 Second Ago
      • 7 Years Ago
      I continue to be stunned how so many so-called car enthusiasts think the Prius is hype over substance. Anyone who thinks that must have never driven one.

      I rented one for a week last time I visited Seattle, and it averaged 49mpg. I drove about 2/3 highway and 1/3 city. It's a roomy, comfortable, quiet car, and truly an amazing technological achievement, particularly when you consider that the current design is about five years old. The next version will undoubtably be even better.

      (And just so you don't think I'm an eco-Nazi, for background, I currently drive a 993 C4, a gas-guzzling V8 Audi S4, plus an old Miata and a full-size Ford van.)
        • 7 Years Ago
        Sweet garage! I want the 911 and the Audi - already got the Miata and a big honkin' vehicle (old GMC truck) :)
        • 7 Years Ago

        No, I don't even follow sports, much less have my own team!
        • 7 Years Ago
        are you microsoft's paul allen?
      • 7 Years Ago
      More people buy diesels in Europe because of company tax benefits or because there cheaper to run or because they need to use the torque and not HP much.

      It doesn't help the Prius when it looks like a strange deep-sea fish or the fact that it costs £2,000 MORE than the equivalent Ford Focus or VW Golf. In the UK at least it doesn't even qualify for free road tax either so what's going for it when most cars look better, handle better and get roughly the same MPG as a Prius?

      BTW, there's no 'special' reduction or tax breaks just because it's a hybrid either.
      • 7 Years Ago
      Why don't we get those cool BMW's here in the States? I Would love to have a 5 series that gets the gas mileage of a Geo Metro. Anyways, you got to think the repair cost on a Prius has to be huge.
      • 7 Years Ago
      Diesel is over 33% more expensive here in CT right now.- regular is about 3.30, I've seen diesel in the 4.50s. If that happens every winter, there's no point to diesel.
        • 7 Years Ago
        Well, when the Germans have to engineer something with the complexity of a lawn tractor, I guess they do all right. Anything complicated, like modern electronics and diesels, I wouldn't trust them for a second. The VW TDI is anything but reliable. Mercedes is certainly not what it once was (and what it once was is often viewed through rose colored glasses, they broke down often enough.) What Toyota has been able to do with Hybrid reliability is something no German company could touch right now. No way in hell.
        • 7 Years Ago
        You are partially correct. Each service for a diesel tends to cost more than for a gas engine. But, you also perform those services far less often.

        Additionally, diesels are built more stout and as such, have a sort of built-in reliability there. Most diesels, modern or otherwise, can go many 100's of 1000's of miles with minimum upkeep. Long haul semis can go a few million miles on a diesel engine, you really don't see many gas engines doing the same. Anytime a gas car(or truck) turns over 1,000,000 miles it seems to get a story written about it somewhere. We'd have a whole book to read if the same happened anytime a diesel vehicle did the same.

        Regarding the point of them being German, I fail to see how that has much to do with it. There are numerous 20-30yr old M-B diesels I see driving around. In fact, I tend to see the diesels more than the gas versions. Not really any Audi's or BMW's though since neither offered diesels here that long ago. VW's also have great reliability with the TDI engines as well.

        Reliability and maintanace is hardly an argument to use comparing diesel to gas engines.
        • 7 Years Ago
        But if your mileage is up 33% (say you're getting 32 mpg instead of 24), it's a wash. If your mileage is up more than 33%, you're coming out ahead. Yes, you'll pay more each time you stop to fill up (assuming the same size tank), but you'll stop less often.
      • 7 Years Ago
      I have found this discussion very educational. As an American living in the UK, I must say I look at diesels in a completely different light now. First and foremost, they are not slow. You get them moving and the torque is phenominal. American's are looking at a diesel from the 80s perspective...WAKE UP, it's 2008 and the improvements in diesles is AMAZING!

      For the BMW, they are beautifully crafted and quite quiet at speed (the diesel). They get phenominal gas mileage. And you think the 520d's numbers are fantastic, look at the 320d's numbers - high 40s in town and high 60s on the highway. You could get that car in the high 20s/low 30s here if they introduced it.

      For the Prius, I recently drove one while stateside in January and I loved driving the car. I found it to be a game on wheels--how could I get the car to run predominantly on electricity. I got great mileage and I really felt that once I got the hang of the gas/electric motor trade off that I was doing my part to be cleaner. And the performance isn't that bad either.

      I'm a gear head and a speed freak, but as I get older I realize there are trade-offs in life. Start looking at cars as a half full glass of Pinot--lots of opportunity waiting to be discovered.

      • 7 Years Ago
      I'm sorry, I couldn't hear you over the 0-62 in 10 seconds figure of the 520d.

      Diesel or gas, if you make a car crap slow, the mpg gets better. The reason Americans think Diesels are some kind of revelation is because they don't have any economy-orient gas cars to choose from.

      Make a version of the 5-series that does 0-62 in 10 seconds on a gas motor and watch what the fuel economy is. It'll also be cheap to run, emit less CO2 and probably cost less to buy.
        • 7 Years Ago
        I don't know why you guys are spewing this 10s figure. BMW states it at 8.6s, and 8.6s isn't all that slow considering the small engine and the weight of the car.
      • 7 Years Ago
      i really not a Prius fan. i really hates the Prius's HID lights.....it has very poor focus on the road...and hurts people eyes when they're looking at the rear view mirrors.

      btw, i've heard that the Prius battery last for a long time, but if it fail the whole set of battery cost about 5K total.

      Hybrid and electric motors is old news, i am more interested in compressed hydrogen cars.
      • 7 Years Ago
      uhh.. aside from different price points for the cars and little details of teh diesel and gas difference the biggest difference is the maintenance and infrastructure. there are very few diesel pumps and maintenance will be a pain in the butt. Prius has less maintenance than a gas car since it uses those gas parts less, does a diesel have less maintenance than a gas car?

      hmm. better yet, check out project better place and renault-nissan ev project. that'll top both the prius and diesel.
        • 7 Years Ago
        Richard, he's referring to many urban areas that do not have guaranteed Diesel fuel pumps. I know in my area you'd have to look for it.
          • 7 Years Ago
          Well, all I can talk to for urban areas are Austin, Dallas, Madison and St. Louis, but having driven a diesel truck in all four of those towns, I didn't find pumps hard to find at all. I'm guessing that most of the other diesel vehicles don't have a problem either. Do all stations carry diesel? No. Its not as common. In my experience though at least 1/3 of them do, and with a gas station every couple of blocks that's really not too hard to find.

          That may well be different in other cities, but - after all - even if no personal use diesels exist (and they do), they all have delivery vehicles, tow trucks, etc. But seriously, its not at all hard to find.
        • 7 Years Ago
        [ replying to "what?" in case AB loses the thread ]

        Yeah, the lack of diesel in the US explains why nobody is buying those big, smoky, heavy duty diesel pickups. Oh, no, wait a second, they're selling like crazy. Hmm. I guess the extra maintenance is what's doing it. No, I'm wrong again, diesels regularly go 250K miles without more than oil changes. It must be that the batteries in the Prius will never need maintain... no, that's not it either.

        Maybe its just that you're incorrect in this instance? Diesels have been sold, successfully, in this country and indeed all over the world and have fantastic track records for maintenance and reliability (not including the awful 350 gas-to-diesel conversions GM dropped on us in the 80s). There are plenty of pumps, even in the US. And historically, diesel has retailed for less than 87 octane.
      • 7 Years Ago
      First, the Prius. I happen to think that it gets a bit of a bad rap, albeit mostly because of being overhyped. After all, if you look at it as a roomy, comfortable, ultra-quiet car that seats five with a good trunk that gets, oh, let's say 40mpg (being conservative) and can be bought for $25k loaded... isn't that a good thing?

      I mean, seriously, that's a lot of efficient transport for that kind of money. Ignore the internals and just look at the results, and I think most people would be impressed. Instead, they bash it for not getting 60mpg and go for the 20-25 mpg Accord/Taurus/whatever instead. Huh.

      Now for the BMW. In the original article it points out that it retails in the US for 27,190. That's only 30% more than the Prius. Put it this way, if this was the same price difference in the US, the 520d would retail for about $35K (it is quoted in the article as being by far the cheapest 5er). Not too bad. And the performance? While it is indeed no M5, 0-60 in 8.3 isn't exactly terrible for a big, comfortable cruiser like this one. Measured city mileage was around 33 US mpg (40 imperial).

      Again, ignore the internals. Let's say you could get a car as comfortable as a 5 series BMW that did 0-60 in 8 seconds and got 33-50 US mpg (their combined test revealed a 46 average mpg) for $35K ... wouldn't that be a pretty good deal too?

      So there you have it. Two cars, each more fuel efficient than just about anything else in their price/size range. Each one with far less emissions than almost anything had five years ago. Aren't they both pretty damn good at what they deliver?
      • 7 Years Ago
      Keep in mind that Diesel fuel has about 15% more energy than Gasoline.

      Prius did better than 520d in term of efficiency at it's game (on the highway).
      • 7 Years Ago
      Please. All these people whining about the test being unfair?! I mean if you always do urban tests yea, the Prius is gonna win. But not everyone drives all urban. It is only fair to see how the Prius stacks up for someone who might do a lot of highway driving. It is good to know, for if you mostly do highway driving and want to save the world, maybe the Prius isn't for you. If you want to look all cool driving around a Prius and be a poser, then these tests shouldn't even matter to you :).
        • 7 Years Ago
        The problem with this test is that it's so patently biased towards conditions that favour diesels that I'm surprised AB (and ABGreen, even) posted it...

        ...unless they were trolling for post counts on a slow weekend.

        We know the Prius doesn't do as well at highway speeds. It doesn't do badly** at all, but it's not all in it's element. If this test had been run in central London in rush hour, I'd have complained that it was equally unfair to the BMW. But we wouldn't see that test on AB, because picking on the Prius is practically a sport here, second only to picking on the Tundra and only slightly ahead of picking on the 2008 Focus.

        ** (note that the Camry hybrid gets better mileage than the Camry I4 on the highway, despite weighing more. The delta is less than that of the city figures, but it's still appreciable; hybrid batteries aren't dead weight)
      • 7 Years Ago
      I found a video of this comparison: http://www.autojunk.nl/clips/view/137887
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