BMW 520d Beats a Prius in Efficiency

Ralph Mar 24th, 2008 Link

I think what is forgotten is that it’s not only about mpg, it’s also about emission into the air.(Gasoline/diesel vs Hybrid) While the BMW got slightly better mpg than the Prius, the Hybrid output of emissions (carbon dioxide) in city driving (when the electric motor mostly kicks in) is much lower than any gasoline or diesel engine.

Whether one believes (or doesn’t believe) that carbon dioxide contributes to Global warming, many scientist do and believe that both gasoline and diesel play a big role in Global warming. While the Prius may have been originally built to deceases gasoline usage (dependency), it also plays a secondary role in reducing emissions. With diesel fuel prices now the same or higher than gasoline, I don’t see the advantage of a diesel car. (Better mpg yes, but pollutes more than gasoline – even the lower sulfur type diesel)

Now I will say when it comes time to replace all those hybrid batteries, another type of environmental issue might happen, landfills with batteries, unless they get recycled.

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Revhed Mar 24th, 2008 Link

This is not really surprising – Hybrids work best in low speed stop/start environments like cities, and diesels work well on the open road – depends on the type of driving you do.

Ralph is correct in terms of environmental impact, but also the BMW no doubt wasn’t fitted with a NOx filter either, another reason why diesels are not as “clean” as many think (unless they have a NOx filter, but few do yet).

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c4 Mar 24th, 2008 Link

I’ll take the diesel any day of the week over a (Gasp!) hybrid.

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mowse Mar 24th, 2008 Link

All I can think when I see someone in a Prius is “what a tool”. If any GW kool aid drinkers read your own bible, the NY Times and even Newsweek you will see that the world temp decreased 1.35 degrees in the last 12 months. The Earth hasn’t been this cold in 30+ years back when they were warning of “global cooling”. Anyone who cares to look it up it is documented by every credible geological source. Time to wake up and smell the hoax you fakers and fools. Ever wonder why Al Gore refuses to publicaly debate anyone on this?

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Nate Mar 24th, 2008 Link

Right on, bro!

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M. Dillon Mar 24th, 2008 Link

mowse…please…and I state this with respect: Stop listening to right-wing talk radio. It let’s the readers here know you’re a mindless sheep.

With that stated,I like this article. It makes great points about the debate about hybrid vs. diesel. Plus,I like how others here are making great points as well.

Thanks guys.

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Chad Mar 24th, 2008 Link

MPG is a pretty meaningless ratio now.

Anyone who really cares about it cares about one of two things, provided that all other things are equal*…

1: MP$, miles per dollar (or whatever your currency is). These people are worried about cars costing too much to operate, and so opt for a smaller engine or a better designed one to save on fuel costs. I don’t know if anyone buying a BMW 5-series is all that worried about saving a buck at the pump every couple weeks, but bear with me on this one. In the US, at least, diesel is WAY more expensive than gasoline, so the Prius may be much better in the MP$ catagory.

2: EPM, emissions per mile. These people are worried about being environmentally responsible (albeit, they almost never seem to care about the ecological impact of building and importing a new car).

• of course, not all things are equal. No way you can replace a Sprinter with a Prius, nor would someone cross-shop a BMW and a Chevrolet.

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mowse Mar 25th, 2008 Link

MD. Unlike you apparently I can read. Didn’t hear this on the radio but several sources which are publicly available if you can digest more than a bumper sticker As for sheep it is you panty waist twerps you jump on the phoney “I care sooo much about the planet” bandwagon who eat this bs up. Why don’t you learn the facts and make up your own mind? Even if humans could make a dent in the climate it wouldn’t make a sliver of difference if the entire western hemisphere rode bikes instead of cars. It’s China and the third world who would do all the damage Use your brain, not your “feelings” people.

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mowse Mar 25th, 2008 Link

The sound of crickets………

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Roger Mar 26th, 2008 Link

Mowse,

The reason you’re hearing crickets is that the folks you’re attacking are choosing not to engage in a battle of wits with an unarmed opponent.

I will be so bold as to correct you on one major mis-statement — the US represents approximately 5% of the world’s population, yet we consume 25% of the world’s production of carbon-based fuels. You are correct that if China and India were to emulate us in our profligacy / life-style, we’d all be in even deep(er) trouble regardless of whether we all took to riding bicycles in the US and Europe, but they are still far, far behind us in their per-capita fuel consumption, and are unlikely to ever match us.

All (reasonable) forecasts show that the per-capita energy is unlikely to ever match today’s levels again, unless we successfully find a way to harness fusion power. We can argue about whether Peak Oil will occur soon (or already has occurred, as some assert) and whether there’s 200 years or 300 years of uranium for as-yet unbuilt power plants, but the fact is that “civilization” may actually be at its peak right now unless we find another energy source — soon. More efficient vehicles can put off the day of reckoning, but cannot prevent it.

I drive a MINI because I enjoy driving and especially enjoy driving a fun car while doing the least possible harm to the environment. And I’m a hypocrite — I should ride a bike more, and so should you and all the rest of us.

It took 50 million years (during the Carboniferous Era, 330 to 280 million years BC) for the carbon to be laid down to ultimately convert to oil, coal, tar sands etc. and we’ve gone through half of the world’s supply in 150 years. That is not a sustainable rate of consumption, regardless of what you might think of Mr. Gore’s thesis about the effects of C02. That’s the real problem that no politician wants to talk about, for fear of suffering the same (political) fate of Jimmy Carter. Say what you want about the man, but he was absolutely correct about our entering an “era of limits”. The populace didn’t want to hear about and end to “bread and circuses”, so instead in 1980 we elected Ronald Regan, who, as one of his first acts, removed the solar panels that Carter had had installed on the White House.

Sigh.

So, Mowse, what is the real significance of the Global Warming (or Cooling, for that matter) debate if our great great grandchildren will be shivering in the cold wondering what the heck were we thinking by driving down to the corner grocery in our 6000 pound Hummers for a six-pack?

– Roger

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mowse Mar 27th, 2008 Link

“The con man does not aim to covince the skeptic, but rather enable those who believe what they want to believe. The useful idiot”. RIP common sense and free thinking.

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mowse Mar 27th, 2008 Link

“The con man does not aim to covince the skeptic, but rather enable those who believe what they want to believe. The useful idiot”. RIP common sense and free thinking. Roger, you are full of s*** just like the rest of your crowd. You mice can believe whatever sky is falling religon you want. I’m just sick of having to read it on what SHOULD be an agenda free forum. I don’t read this to be preached to by fools. Keep the delusional dogma to yourself.

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Woody Mar 27th, 2008 Link

Clean diesels (ultra low sulphur fuel & associated exhaust filter/scrubbers) are efficient and have low-emmissions. How about combining one of these new diesels with an electric motor to make a diesel hybrid? Crazy idea… I don’t know the price of diesel in the States right now, but in Europe diesel is cheaper – there’s far greater use of diesel in passenger cars in Europe.

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mcswrks Mar 28th, 2008 Link

“mowse…please…and I state this with respect: Stop listening to right-wing talk radio. It let’s the readers here know you’re a mindless sheep.”

…..

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mowse Mar 28th, 2008 Link

This “right wing radio” insult is so lame. The idea that “cons” are sheep is a joke. Is it those of us who word hard,have six figure incomes, and high standards are sheep or the pathetic whiney “victims” of the world who lack the spine to do anything but say “yes” who are the sheep. I’ve yet to see anyone contradict my FACT that the world has cooled. Only limp shots taken at me. So if mindless sheep only get their opinions from “RW radio” where do you pansies get your info? From politicians (like Carter???)or selfserving svengalis like Gore? Michael Moore? Can you say BAAAAAA? Those of you who subscribe to platitudes instead of facts have no credibilty. Just look at the people who share your views. The losers of the world looking to find someone to blame for their unhappy existance. This is the only down side to owning this awesome fun car. It has good gas mileage and is “eco-friendly” so it attracts too many gutless wimps. I think I will go drive my SUV around for awhile to get the taste out of my mouth.

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Average Jane Mar 28th, 2008 Link

Diesel reek. No matter what, within a few years even the “new” technology will be belching blue smoke and asphyxiating the people driving behind them.

I went with a Prius because of that. Between my Mini and my Prius I have enough carbon credits to feel relatively guilt-free driving my M35x. :)

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Timothy Mar 29th, 2008 Link

NASA has some nifty graphs if you’d like to see the rise in world temperatures dating back to 1880:

http://data.giss.nasa.gov/gistemp/graphs/

But we actually have indirect temperature data going back much further than that, using observations from the geological record, ice core samples, and that sort of thing. The data from 1880 forward involve direct human measurement using highly accurate (especially over these long periods) science-quality temperature sensing equipment.

Mowse is arguing (I guess) that an arbitrary single year might see a reduction in mean global temperatures. Fair enough. Now let’s see that trend sustained over, say, 30 years before even beginning to consider holding back on aggressive steps to reduce greenhouse gases. Because the fact is the planet is in trouble, and mankind is causing the trouble. There is no serious scientific debate about that. And we should expect the occasional year or five of temperature decreases amidst the secular upward trend. Mowse is basically arguing the equivalent of a long-term investor selling all his stocks on the basis of a one hour 3% decline in the stock market, and I guess he’s hoping you’re too stupid to figure out why that’s insane.

Moving beyond that, there are several problems with the BMW 520d v. Toyota Prius example in terms of judging whether hybrid powertrains are the way of the future or not. The biggest one is that almost no one actually drives from Geneva to London. Driving cycles should represent real driving, and that’s much more urban-centered, especially in Europe. The second problem is that we’re comparing diesel fuel with petrol (gasoline). It’s certainly possible to build a diesel-electric hybrid. (That’s what diesel railroad locomotives are.) A diesel-electric hybrid would consume fewer gallons than a petrol one because there’s more energy per gallon of diesel, ceteris paribus. The third problem is at the tailpipe (as already mentioned): diesel engines aren’t too great on that score. A fourth problem is that only a hybrid powertrain can be plugged into the grid, with electricity generated from any source. A French driver consuming grid electricity would draw from mainly nuclear power, with effectively zero greenhouse gas emissions. Usual trips, and the first part of longer trips, would be fueled entirely from the grid. A Prius doesn’t do that from the factory, but modifiers have added that capability, and hybrid manufacturers are going to be doing it, too, in their next models.

Does BMW sell even a single hybrid vehicle? If not, that concerns me.

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Timothy Mar 29th, 2008 Link

By the way, I’m not a hypocrite (much). I live in Japan, and I don’t own a car. You don’t need one here. Per capita, the Japanese emit much less than half the weight of greenhouse gases as Americans.

Homes are not typically McMansions, and they are super-efficient. For example, I get hot water in my apartment “on demand” and can control whether the heater fires from a button on the wall next to the kitchen faucet and bathtub. There’s no hot water tank to keep warm. The insulation is so air tight that the apartment needs outside air vents, and sometimes when I open my front door there’s wind as the air pressure equalizes. I have a remote control for individual room-based heating and cooling, and I can also control my apartment’s heating and cooling over the Internet if I forgot to turn it down (or off) before I left. Effectively I only heat my bedroom, and only at night. (There are big, heavy doors between rooms.) The gas company has mandatory annual inspections to make sure everything is working to peak efficiency. I even got a letter in the mail from the water company asking for an explanation why I used more water (above trend) one particular month.

My Asko washing machine, dryer, and dishwasher, and my Hitachi refrigerator, are all incredibly efficient. (My refrigerator beeps if I leave the door open too long.) Most Japanese cook using toaster ovens and/or microwaves, and large ovens are a rarity.

The Japanese love their hot baths, so there is a fair amount of hot water heating about twice a week. But they will use a hand shower first, clean themselves completely, and share bath water (with an insulated cover) among household members. So they only heat the water once for everybody. This probably sounds gross to a lot of westerners, but it actually works quite well and is very traditional. And they scrub and scrub before stepping into the bathtub. Pre-cleaning is pretty common in other areas. For example, when entering a home (and some inns and restaurants) you don slippers and remove your street shoes. Doing so minimizes the amount of floor cleaning (and associated energy use). You swap slippers for the toilet room. And they do love the high-tech toilets, so there’s a bit of energy use there for the electric bum warmer and washer, but there’s also less toilet paper used as a consequence.

Everything is recycled that is possible to recycle. My nearby rubbish room has something like 6 bins for sorting different parts of the household trash. There’s a fee for disposing of anything much larger than a breadbox, so there’s a strong incentive to give things away, even furniture, and not to buy crap you don’t need in the first place. When you buy a car there’s a mandatory recycling deposit, and you only get that back when you properly dispose of the car. (I’ve never seen a rusting car rotting in some backyard, even in rural parts of Japan.) Taxi service is everywhere, and a lot of the taxis are Toyota Priuses. Many others are CNG powered.

Subway and train service is frequent and goes everywhere, and there’s a common fare card with direct bank debit if you want. A lot of the electricity to operate the rail system comes from nuclear power. In the past two years I have only ever experienced a single train that was delayed more than 5 minutes, and that was due to a “fender bender” (no injuries) which made big news because it’s so rare. For intercity travel I can get from Tokyo to Osaka in a typical 2 hours 33 minutes on Japan Rail. That’s almost exactly the same distance as Boston to Philadelphia, which takes about 5 hours on Amtrak’s Acela Express. Amtrak has 8 daily weekday Acela trains each way on that route, while (as I check at this instant on a Sunday) just counting the Nozomi trains, Japan Rail has departures at least every 10 minutes on that route. (The “slower” Hikari trains still take under 3 hours on that route.) The fastest train is the new N700 service which gets the Tokyo-Osaka trip down to 2 hours 25 minutes. (The N700 trains tilt on the curves and can accelerate to 270 Km/hour in 180 seconds on their way to a 300 Km/hour top speed.) The on-time performance of the shinkansen is ridiculously excellent, while Amtrak’s best (Acela) is still quite mediocre. Walk-up one-way fare is about $142, while an Acela one-way is $216.

Since shinkansen service opened in 1964, the only fatal accident I’ve ever heard about is in 1995, when a boy got his finger trapped in the door as he tried to board too late. The train’s sensors and crew didn’t detect what happened, the train took off, and he was dragged to his death. Japan Rail improved the sensors since then, so the doors can detect a child’s finger. The only other accidents are when someone jumps onto the tracks, typically suicides. When you think about how many people die in car accidents it’s a major safety accomplishment to have so many people riding trains instead.

Now, I have (foolishly) driven the Tokyo-Osaka route. Without traffic and without stops it’s something like 7 hours. But, especially near Tokyo, especially returning on a Sunday evening, the local traffic can be frustrating, adding an hour or two to the journey. Tolls are roughly $100 each way, and gasoline is up around $7 per U.S. gallon now, so you’re a damn fool to drive unless you’re driving a bus.

Speaking of cars, though, over a third of Japanese cars are “kei cars.” These mini cars get special tax treatment because they use 660 cc engines. They are quite efficient: one of them hits 27 Km per liter, and 25 is typical. For car owners a kei car is often their only car, and almost without exception in the few two-car households it’s the second car.

There’s a lot less use of electricity for things like computers. More people use mobile phones for Internet access than use PCs, for example. (You often see a majority of passengers on the train using their mobile phones to answer e-mail, browse the Internet, order movie tickets, whatever. And what a time saver to be able to do that while in transit.) The PC never became as popular in Japan for a lot of reasons. Even in my office everybody uses small (~1.2 kilo) notebook computers rather than more power-hungry desktops.

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Kat Mar 29th, 2008 Link

I’m sure Mowse will chime in soon and assert that scientists are also sheep, and that only he has the correct viewpoint on the “fact” that global warming is a sham and that (oh by the way) we also have an infinite supply of oil.

A couple of things about hybrids and plug-in hybrids:

1) It’s not completely obvious that hybrids are as green as they appear to be at first or even second glance. As you are (I’m sure) aware, they have two drive trains — this addtional complexity, along with the difficulty and expense of recycling the batteries, has a negative impact on the lifecycle cost of these cars. During their operational lifetimes, (while the batteries are still in good shape, see below) especially in city driving, they are extremely efficient in terms of gas consumption. It’s before and after their operational lifetimes (during the engineering/manufacturing phase, which is extended due to their system complexity, and in the recycling phase) where their real “costs” show up.

Also, in a hybrid car, the battery set will not last for a normal (imported) car’s lifetime, so somewhere along the way the owner will either scrap the car or spend some large coin (quite probably more than the money saved buying gas during the ownership of that battery set, especially if the true cost of recycling the batteries is included) to replace the battery set. NiMH batteries are nasty to recycle. I won’t delve into why you can’t buy a car with LiH batteries (yet).

2) Plug-in hybrids look fabulous (100+ MPG!), until you realize that the electrical losses between the power plant and the consumer eat up all of the real benefits. The line losses are on the order of 2/3rds to 3/4s of the delivered power — for every three or four Watts that leave the power plant, only one comes out of the plug in the wall and into your car. The rest goes into heat due to ohmic losses in the power lines between the plant and your house. If that power was generated by coal or oil, you’ve actually created more CO2 than if you just burned gas in your hybrid car. Electrical plants are extremely efficient converters of carbon-based fuel into energy, but not 3 or 4 times as efficient. :^(

If the power was generated with a nuclear power plant, then additional CO2 isn’t the problem, though we all know that recyling or disposing the radioactive material from nuke plants is problematic.

TANSTAAFL

– Roger

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Mowse Mar 31st, 2008 Link

This has to stop. I will end this by finally stating that we all must agree to agree that I am correct and you are all fools.

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Leaves Rustle » Blog Archive » Wrapup, Textish Edition Apr 14th, 2008 Link

[...] BMW 520d Beats a Prius in Efficiency: “…on a 545-mile London-Geneva run, when a diesel-powered BMW 5-series posted better MPG stats than a petrol-based Toyota Prius hybrid. The BMW 520d with a 2.0-liter diesel engine and regenerative braking posted an impressive 41.9 mpg – about 0.9 mpg better than a full hybrid Prius. The difference may not seem huge. But given that the Prius weighs about 500 lb less, BMW’s fuel economy lead was significant enough to raise new questions about which drivetrain technologies are more envir [via motoringfile] [...]

Kat (Roger) May 2nd, 2008 Link

“The line losses are on the order of 2/3rds to 3/4s of the delivered power — for every three or four Watts that leave the power plant, only one comes out of the plug in the wall and into your car”

I wish to correct my mistatement. I was misinformed. The actual line losses between the utility power plant and your wall outlet are more on the order of 7-11%, which is a remarkable acheivement on the part of the power company. I apologize if my error has caused anyone any heartburn.

– Roger

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