The article mentions "40 miles a gallon (U.S.) or about 5.9 litres/100 km" for a medium sized car (think Toyota Corolla). Doesn't strike me as "super-efficient" at all, this is what cars have been doing for years already! Or am I missing something?
The United States Environmental Protection Agency (EPA) laboratory measurements of MPG have consistently overestimated fuel economy.[ This results in a shortfall of about 15 percent in actual vs. measured CAFE goals. Starting with 2008-model vehicles, the EPA has adopted a new protocol for estimating the MPG figures presented to consumers. The new protocol includes driving cycles more closely representative of today's traffic and road conditions, as well as increased air conditioner usage.
Color me skeptical, but the only reason the auto-manufacturers are doing this is because if they don't, they will lose out to the hybrid and electric markets. Without the hybrid and electric markets, they wouldn't bother.
So there's your dilemma. Support the hybrid/electric market, even though you pay more and get less, or don't. If no one does, then the hybrid/electric option will implode, and the petroleum-only option will stop innovating.
Can anyone here suggest an alternative view? (I suspect yes)
Color me skeptical, but the only reason the auto-manufacturers are doing this is because if they don't, they will loos out to the hybrid and electric markets.
You are skeptical of GDI's effectiveness (to help competitiveness), based on your perception that it is in fact effective?
Without the hybrid and electric markets, they wouldn't bother.
There are no other market pressures to improve gasoline engine efficiency and performance? What about:
Direct competition from other gasoline-engine makers.
Fuel cost.
Market-distorting legislation (CAFE, etc.).
Upon re-reading before submission, this is too long. I remind you of Pascal's lament. My apologies. It's also slightly rambly, and shows that it's been edited lots of times. Again, sorry. I don't have time now to take it out and write it more coherently.
I wrote: Color me skeptical, but the only reason the auto-manufacturers are doing this is because if they don't, they will lose out to the hybrid and electric markets.
gravitycop wrote: You are skeptical of GDI's effectiveness (to help competitiveness), based on your perception that it is in fact effective?
No - you appear to have misunderstood my point. GDI is certainly effective at reducing fuel consumption. I don't exactly know all of the technological ins and outs, but I have seen reports that engines in Europe have had very similar technology for a long time. Certainly I get over 40mpg in my petrol car, and my wife gets over 60mpg in her diesel. I'm pretty sure it does work.
My point is that manufacturers haven't bothered seriously investigating things like this, because the market forces have not previously been sufficiently strong.
I wrote: Without the hybrid and electric markets, they wouldn't bother.
gravitycop asked: There are no other market pressures to improve gasoline engine efficiency and performance? What about:
Direct competition from other gasoline-engine makers.
Fuel cost.
Market-distorting legislation (CAFE, etc.).
I'm not claiming there are no other market forces. I do, however, believe that it is only since the wider availability of hybrid/electric vehicles that the petroleum-based engines in the USA have started to improve significantly. I do not have scientific evidence, but I do not believe this to be a coincidence. It is my opinion. It may be wrong.
I'm not particularly an advocate of either petrol of diesel, and my comment was not intended to indicate a preference. I simply believe that fuel efficiency has not been of primary concern to manufacturers. Secondary, yes. Primary, no.
This is probably not the place to have an extended onversation about the topic, but, in short, I believe that the petroleum-based engine manufacturers in the USA are only now starting to take seriously the problem of producing efficient engines. I believe that engines in Europe are generally more efficient, and the USA manufacturers are starting to use similar technology and trumpet it as "all new and improved!!"
Whether my opinions on this are relevant to HN is doubtful. For completeness, I also believe their change of heart is primarily driven by the advent of affordable alternatives. Without the hybrid/electric alternative I believe they won't bother too much about fuel efficiency. I don't think the market forces even now would be strong enough. With the hybrid/electric alternative, they are. Hence the dilemma I tried to raise, probably badly.
I hope that makes my position clearer. It's also probably entirely irrelevant, and adds little value. I shan't reply again unless I think it will.
If you haven't corrected, you are achieving over 33.3 miles per U.S. gallon when driving your high-smog-pollution (i.e. European liberal smog-emission standard, which allows ceteris paribus for higher fuel economy) gasoline-powered car. [EDIT] If you have corrected, your results are still not comparable, since they were achieve in a high-smog, and therefore illegal for the U.S. market, car.
Sorry for not specifying, but I've already corrected for that. I don't deny that the diesel car probably wouldn't meet the emission standards in the USA (which bit? Hmm) but that's not my point.
And I don't really care. I wish I hadn't bothered to comment. What happens to your replies if I delete my submissions/comments?
I don't deny that the diesel car probably wouldn't meet the emission standards in the USA
Both the diesel and gasoline (petrol) cars, if made for the European market, do not meet U.S. smog-emission standards and therefore are not directly comparable in terms of fuel-economy.
Somehow this has turned into a Europe vs USA "discussion". That was not my intention. I have no particular axe to grind, being neither European, not American.
Further, it seems clear that the point I was trying to make is not going to be heard, and other points - no doubt valid, but nonetheless tangential - are going to dominate. Perhaps it's wrong, perhaps no one wants to hear it.
Perhaps I just can't express myself clearly enough.
So I'm simply going to walk away from this thread. You have made many valid points which I will remember. Thank you.
I believe that engines in Europe are generally more efficient, and the USA manufacturers are starting to use similar technology and trumpet it as "all new and improved!!"
The fact that European car manufacturers are unable to export their cars unaltered to the United States is due to the fact that European cars fail to meet U.S. smog-emission standards. Manufacturers do not, and cannot because of U.S. smog-emission laws, use European engine technologies in cars for the U.S. market. They have to come up with "new and improved", as you say, technologies that meet U.S. smog-emission standards while achieving whatever other goals they have in mind (fuel-economy, performance, reliability, smoothness, driveability, quietness, etc.).
Virtually all diesel engines use direct fuel injection so a large percentage of European cars are already taking advantage of this technology (which, by the way, was invented in the 1950s).
Virtually all diesel engines use direct fuel injection so a large percentage of European cars are already taking advantage of this technology
Diesel engines do not directly compete with gasoline engines in the United States. The reasons are:
Poor performance.
High cost.
High mass.
High bulk.
High smog pollution.
High noise pollution.
Gasoline direct injection is a new (not invented in the 1950s) and important technology that substantially improves the competitiveness of gasoline engines against diesels, electrics, air-cars, etc.
> None of these things are true any more, nor have they been for some time
For smog, especially particulates, that depends on what you mean by "some time". Until a couple of years ago, diesel cars were't close to satisfying CA's requirements. (The switch to low sulphur may have also helped.)
FWIW, diesel-hybrids would be especially effective because diesels have a much narrower "90% of peak efficiency" range of RPM and load.
diesels have a much narrower "90% of peak efficiency" range of RPM and load.
Isn't that gasoline engines that have a narrow range of near-peak efficiency? Diesels do not use airflow-restriction to throttle power. Gasoline engines (current embodiments, at least) do use airflow-restriction to throttle power.
> Isn't that gasoline engines that have a narrow range of near-peak efficiency?
Nope. Read the wikipedia article, especially the last paragraph of "Reliability". (Part of what's happening is that diesels have a smaller overall range, so even if the "90% peak" ratio is bigger, the width of the range is smaller.)
Also, diesel engines' fuel consumption doesn't vary as much with load as do gasoline engines'. (Again, see the wikipedia article.) This makes diesels especially good for hybrid use as it means that they can drive the generator "for free" while the car is being driven with the diesel running at less than full power.
At this point, history [is holding the diesel back in the American market]. The diesel "brand" was badly hurt by the early versions.
You said that none of those diesel-drawbacks I listed have been true for some time. If that were the case, it might seem that the public is taking its time coming around. here is a recent forecast for diesel market share in the U.S.: http://news.google.com/news?q=%22diesel+market+share%22
Automotive industry analysts at JD Power have forecast that diesel market share in the US will quadruple to 9 percent by 2015
Only 9% market share by 2015? And the technology has no drawbacks in comparison to gasoline?
That's a pretty weak argument. Anyone can make a market share prediction, and our track record at this kind of prediction sucks.
And in any case, market share quadrupling between now and 2015 in an automotive market is rapid adoption.
How about a counter-argument based on the lack of availability of diesel pumps? Seriously, that's the worst thing about owning a diesel car-- trying to find a gas station that pumps diesel.
Yeah, that's exactly the problem. I live in Boston, where the vast majority of drivers are commuters, and nobody even knows what a generator looks like.
My best search algorithm is to locate the nearest freeway exit, then find the nearest gas station.
That's a real mystery to me. Seriously, it's baffling.
I live in the US and drive a diesel Passat, and I regularly get 40+ mpg without paying attention to how I drive or particularly close attention to whether my tires are fully inflated.
To address the comparisons you brought up above, some are clearly wrong:
High mass-- irrelevant; gas mileage is higher.
High bulk-- irrelevant; the car is normal sized.
High smog pollution-- not since the introduction of ultra-low sulfur diesel in the US in 2007.
The particulates are still worse, but diesel wins on the rest, mostly through efficiency.
That leaves the causes of the poor market acceptance as
Poor performance.
High cost.
High noise pollution.
Something else we haven't thought of
I can't speak for anyone other than myself, but the performance is great; the acceleration is particularly good above 30 or 40 mph. From a maintenance perspective, I have done literally zero maintenance on the car in the 3 years I've owned it other than to fix a leak from a clogged roof drain.
On cost, I've been saving money on gas on a per-mile basis since I bought it. So far, I think I've saved around $1000 on gas. I don't know about the market price for diesels vs. equivalent gas cars across the market, but I'd be surprised if I lost on this.
The difference in engine noise is not noticeable inside the car; I don't know whether my neighbors hate it or not. I am quite certain that engine noise was not a factor in my purchasing decision at all.
So, I don't know, gravitycop. I'm as mystified as you are. If diesels are this great, why doesn't everyone in the US buy them?
My best guess is that people don't think of it as an option. They remember the loud, smelly diesels of the 70's and think, "Hell, no, I want a nice shiny Honda Accord!"
How can one make a car's engine heavier without certeris paribus making those two things worse?
High bulk-- irrelevant; the car is normal sized.
Engineers have to shoehorn engines into engine bays. The larger the engine, the more expensive the shoehorning. Their are myriad examples in the automotive press of automakers running into the engine-bay-size obstacle when trying to fit larger, more-powerful engines into existing car models.
High smog pollution-- not since the introduction of ultra-low sulfur diesel in the US in 2007.
NOx emissions are not affected by fuel sulfur level. Cleaning up the smog emissions of diesels still requires expensive bandaids that gasoline engines (as long as they operate at low-enough temperatures) do not require. If diesel-level NOx emissions were allowed for gasoline engines, then ceteris paribus gasoline engines would be more powerful and efficient and less costly.
The same emission limits apply to all vehicles regardless of the fuel they use. That is, vehicles fueled by gasoline, diesel, or alternative fuels all must meet the same standards. Since light-duty emission standards are expressed in grams of pollutants per mile, vehicles with large engines (such light trucks or SUVs) have to use more advanced emission control technologies than vehicles with smaller engines in order to meet the standards.
European governments introduce market disortions that favor diesels. They also allow high smog emission levels, which again distorts the market in favor of diesels.
Recently, there was a year in which there were no diesels at all on the American market, because no diesel at that time could meet the required smog-emission regulations. The trend has been: Americans care about clean air, and Europeans do not, and therefore the latter have been more willing to operate diesel cars.
Market distortion that favours diesels ? You should come and have a look then:
- higher road tax for a diesel, in some countries 200% more than a gasoline car of the same weight
- extra requirements such as factory installed particle filters on diesel exhausts
- extra tax penalties on diesel fuel
Europeans care about clean air very much, and most European cities I've been to compare favourably with the American cities of similar size that I've been to. (Detroit, Los Angeles, New York vs say Paris, Madrid, Amsterdam and Berlin).
In former eastblock countries the situation is worse though.
As for the rest of your arguments, you should test drive a BMW 5 series diesel and we'll talk about power, handling and more of those items you mentioned.
And let's not even get started on reliability, diesels are in a completely different ball park when it comes to that. Here a diesel car that has 200k on the clock counts as 'just broken in', the same chassis with a petrol engine would count as being at 60..70% of its economic lifespan.
Though the engine produces a stunning 425 lb-ft of torque at just 1750 rpm, the forward surge doesn't feel dramatic. [...] X5 owners shouldn't feel too cocky [...]
Press the pedal to overtake [...] and the engine note invades the cabin. [...]
We often hear tall tales of European diesels, stories of ridiculous fuel economy, supercar acceleration, and unmatched utility. [...] the truth isn't quite so dramatic
Comparing a 3.5 liter diesel with a 4.8 liter petrol car, that's like comparing apples and oranges.
Topgear on those same cars, better data: "
All the bigger BMW engines are wonderful and the X5 boasts three of the best. You can go for a ‘base' 3.0i petrol(268bhp, 0-62mph in 8.1 and 130mph), the diesel version of the 3.0litre (232bhp, but because of the extra torque 0-62mph in the same 8.1 and the same 130mph top end), or go for the range-topping 4.8-litre V8 with 350bhp, 150mph and 0-62 in 6.5."
So, exactly the same performance for two 3.0 liter engines by a quality manufacturer, one diesel, one petrol.
And yes, if you increase the displacement the petrol engine will get more power but that is no longer a fair comparision.
That's right and a big part of is the much higher gasoline taxes in Europe.
Interestingly, I can't recall where I read this, but allegedly particles big enough to cause smog are easily filtered by the human body.
Where as particles so small they don't cause smog tend to be absorbed more easily.
And so some clean air regulations might have actually made things worse.
1. The whole world does not live in the USA so the problems of Diesel fuel distribution in the US is not a world wide issue.
2. Diesel fuel has a high energy content and diesel engines are more efficient than petrol engines - thus bulk and distribution costs issues do not apply.
3. Modern diesel engines produce way less smog and noise than the average US car or pickup engine.
4. Gasoline direct injection was invented in 1952 by Bosch.
First of all, the diesel fuel distribution problem is now a non-issue in the US. We have been using ultra-low sulphur diesel for more than a year now.
Diesel fuel has a higher energy content because it is heavier, this requires a higher ignition temp/pressure that leads to the NOx problems others have mentioned.
Modern diesel engines to not produce less smog than a gasoline engine, they produce more. Diesel engines have two problems that gasoline engines lack: they produce more NOx (due to previously mentioned higher combustion temps) and they produce more soot particulates. There are technologies like particulate filters, exhaust catalysts, and exhaust gas recirculation that can partially solve some of these problems, but they are neither cheap nor widespread at the moment.
You are correct about Bosch introducing GDI to autos though.
>> 3. Modern diesel engines produce way less smog and noise than the average US car or pickup engine.
> Modern diesel engines to not produce less smog than a gasoline engine, they produce more.
I think bdfh42 was referring to the existing fleet (including old vehicles) of registered gasoline-powered vehicles. An important point, though, is that newer vehicles tend to be driven more. To wit: the average new passenger vehicle is driven ~15,000 miles per year, whereas the average registered passenger vehicle in general (new+used) is only driven ~12,000 miles per year. The more a vehicle is driven, the more pollution it emits, so it is important for new vehicles to be cleaner than old vehicles.
I don't know the particulars of direct injection for gasoline but I'm pretty sure some of the above reasons aren't valid (at least on modern cars). A friend of mine has an E320 diesel from 2003 or so and performance and noise seem the same as the gasoline version.
$1000 and change north of the base price for the gas-powered E320.
So what do you get for the CDI's price premium? [...] More mass [...] irritating old diesel noise and stink. [...]
The CDI's horsepower rating is modest—201 at 4200 rpm, 20 less than the gasoline engine [...]
With its heavy-duty cast-iron engine block—a diesel trait that hasn't changed much over the years—plus extra sound damping, the E320 CDI weighs in at just over two tons, 219 pounds more than the gas E320 we tested last year [...]
Diesel clatter? Yes, it's still there
The extra weight of a diesel engine causes increased tire wear and worsened handling.
Apparently a number of cars since 2000 already use it. Likewise, turbochargers are old technology. And many of the other innovations in the article apply equally well to hybrid or electric vehicles. With that in mind, the article appears a little desperate.
