Efficiency, Imported From Europe | Hacker News Reader

Efficiency, Imported From Europe

nytimes.com

30 pointsjoshrotenberg30 comments

I always wonder why these big V6 engines are still so common in the US. I'm driving a 2 liter diesel in a BMW X3 (a heavy car, 4wd, automatic) and still get 34 mpg. The 2 liter engine is plenty powerful for this big car. Too powerful maybe, looking at the speeding tickets I got with this car since I have it.

A modern 3 liter TDI is crazy powerful. I really see no practical use case for those engines, other than engaging in speeding contests between Audi's, BMW's and Mercedeses in the leftmost lane of the autobahn. And since there is no autobahn in the US, why do they buy them? I think for normal cars, 1.6 - 2.0 liter 4 cylinder is enough.

Pissing contest mostly. And also some thinks it help with erectile dysfunction.

V6 engines are typically smoother and produce more torque down low in the powerband, which is the range most people drive. So even though the peak capabilities are overkill, basically, an engine capable of 160mph is nicer to drive at 65mph than an engine capable of 85mph. As a result, they are desirable to many consumers. Tiny 4 cylinders are catching up, but that's the thing- it has always been a game of catchup for the 4 cylinder.

Oh, and further in defense of the V6- remember not everyone has the same needs as you. I have recently come to own a 4.0L V6. Ridiculous, right? Twice as many liters and twice as many cylinders as I ought to need. Except, at 12,000ft you've suddenly got a lot less engine. My old 2.2L H4 at-speed required pedal-to-the-metal to gain speed, and 4k+ RPM just to maintain speed.

I just prefer flat six to a V6. Smoother power delivery.

An H6 definitely has some upsides over a V6. A V6 has never been the "best" engine in any specific regard; it strikes a nice balance in the spectrum of the many, many compromises an engine makes.

For example, a V6 can be used in a transverse mount vehicle, which is the majority of vehicles available today. It does this with minimal sacrifices in performance compared to an H6, which is much too wide to ever be considered.

Diesel engines have lots of torque, at low rpm. My 2.0d has 280 lb-ft, the same as a 3.7 V6 mustang, at half the rpm.

Certainly! But for better or worse, America's cars are still mostly gasoline-powered. Diesel isn't just a simple add-on like satellite radio, it is a paradigm shift.

Also remember that the V6 is a compromise of many factors. Besting a V6 in one specific regard doesn't mean much, because a V6's strength is that it achieves many different goals, all at the same time- even if it isn't the best at any one thing.

I don't mean to say a gasoline-powered V6 will always be the only option, or anything like that. But it is interesting to learn the various reasons they are as popular as they are, and it is instructive in how the auto industry operates.

The government is not subsidizing diesels because it's yet another combustion engine. Other than the quoted "industry representatives" want you to believe, diesels produce plenty of carcinogenic, extremely difficult to filter particles. If anything, the government should be taxing these cars 10+ grand for the extra costs they will incur in the health system down the road.

Diesel is also in no conceivable way a new technology, and from what I know it's rare established hundred-year-old technologies that have been used in consumer products for at least fifty years are given generous subsidies.

Diesel used to be significantly cheaper than gasoline. I believe the price has gone up due to increased demand or less supply. Diesel is less refined than gasoline, and I believe the refineries in the USA are optimized for producing more gasoline than diesel and to change this is not a small or cheap task. There would be pressure from the transport industry, eg trucking, shipping, rail, to keep the price of diesel as low as possible, and restricting demand by restricting the availability of diesel vehicles would be one way.

I would love to get a small pick up truck with a diesel engine - you can't buy one in North America today.

I had several 1980 era Toyota Land Cruisers, a 2500 kg 4WD vehicle, and they got 30 MPG. I literally drove from regina to calgary, 800km, on one tank, which was 84 litres.

That mileage doesn't seem that good to me. I've got a petrol honda accord, it's a 2.2 L and I can drive auckland to wellington (just over 650 km) on a 55L tank. My friends with diesel golf's can do Auckland to Wellington and nearly halfway back on one tank though.

So the diesel mileage isn't that good, except for the part where it's significantly better? Thanks for explaining.

You can't buy a small pickup in the US because of the "Chicken Tax" and CAFE. The chicken tax dates from the early 1960s and imposes a 25% duty on non-NAFTA trucks. The CAFE formula includes both a vehicle's "footprint" & it's weight, and light trucks get penalized.

I agree with you, btw. Honda had a V6 diesel motor under development that would have been used in the Ridgeline (and Odyssey & Pilot), but Chairman Ito stopped work on it. The V6 diesel and 8-speed transmission in the Jeep Grand Cherokee is very impressive and should be a good fit for the RAM 1500 pickup.

Roger. My TDI Golf regularly gets more than 50 MPG on highway trips and averages 36 in our driving which is almost exclusively urban, easily more than the sluggish Honda Fit it replaced.

Unfortunately the VW and Audi still suffer from reliability problems. Two friends both with TDI VW cars suffered (Bosch) fuel pump failure that destroyed their engines to a large degree and cost about $6000 to repair.

That's the reason I have not purchased one. If these repairs were covered by warranty, I'd probably go for it.

How long will that 23 cents a litre fuel difference take to pay off?

Diesel is about 11% more energy dense by volume than gasoline. So if you're buying diesel for less than 11% more than gas, you're getting a good deal.

When I was looking at cars the diesels had a premium of about $5,000 over the equivalent gas car. That's over four years of gas if you drive 15,000mi/yr at 50MPG and $4/gal or 3.75 years at 45MPG. That's something else to consider.

I didn't claim it was economically optimal, only that it gets good mileage.

I get 40MPG highway with a 200HP gas powered car that uses premium gas which costs about the same as diesal. With 4$ gas that extra 10MPG would take 250,000 miles to break even. Unfortunately Diesal also costs more to repair so your looking at well over 300,000 miles before break even vs a small but sporty car.

I'm in the UK and I've have a couple of vehicles, both European and both diesel. Not VW! They are great. I wouldn't buy anything else. Fuel here is expensive so it's a good idea to keep it simple.

I had a 2006 Citroen C3 diesel. Even with the air con on full whack, I could get 64mpg out of it on an average ~60mph journey. In London traffic, I got 52mpg out of it.

I now have a 2006 Fiat Doblo 1.3 diesel van/people carrier. This is a much larger vehicle but it's genuinely hard not to get at least 46mpg out of it with 5 people and a load of crap in it. On my own, 58mpg.

The latter had a timing chain replaced for around £500 but apart from consumables, no problems in several years.

I really don't get it when I see someone in a Dodge Ram (suddenly become popular in the UK?!?) hammering it up the motorways with no load or passengers.

I'm not sure about the UK but in the USA it is easy to write off trucks over 6000lbs as a business expense.

FIAT, fix it again tomorrow. Fiats have a lousy reputation and this is deserved in my experience. Also Puntos are the car I see most often abandoned by the roadside

Fiat produces quite reliable engines. Their multijet engines are unbeatable in the small gasoline engine class (1-1.2l). The JTD engines, while not Mercedes-quality, fare better than VW's TDIs.

Now, if you are talking about electrical wiring problems in their cars, I'll have to concede. It's the XXI century, and they still can't get wiring right.

Well based on the timing chain replacement alone, I'd agree but I've done 40k miles in it and that's been the only problem.

Some people don't get the luck I have out of a Doblo:

http://www.ausmotive.com/images/Fiat-van.jpg

1 US mpg = 1.2 UK mpg

and the EU method for calculating those numbers is, so I hear, more lenient than its US equivalent, so those numbers sound more impressive than they really are.

While diesel high MPG cars are not new in Europe, with for instance the VW Bluemotion [1] , it is not necessarily better than unleaded gasoline.

It's true diesel rejects less CO2 than unleaded gasoline cars but it also rejects more NO2 and has some unhealthy particles [2].

So diesel is good for people who drive hundreds of miles in big landscapes, but in cities and suburb, investing in better unleaded/hybrid cars seems wiser.

[1] http://en.wikipedia.org/wiki/BlueMotion

[2] http://www.cancer.org/cancer/news/world-health-organization-...

I have a diesel VW Golf BlueMotion 1.6 from 2011. Sticking to the motorway at 70mph (which is what I originally bought it for) it really burns less than 72mpg, it's fantastic; in the more prosaic stop/start city commute, it averages out around 50mpg. Still, I spend less than £1k in fuel per year, and it's quite a win.

I really, really wanted a hybrid, back then; but the price of a Prius in the UK was ridiculously high (haven't checked recently), and on long motorway trips it likely wouldn't have paid off.

It's a win in fuel costs, yes, but you need to compare total motoring costs when choosing petrol vs diesel.

£1k/year means you do about 10,000 miles a year? That's typically not enough to justify diesels with a DPF. (Short journeys are not sufficient to clean the DPF)

I do infrequent but very long trips, so that shouldn't be a problem.

VW TDI engines either combust the nitrogen oxide or mix it with urea to reduce emissions: http://thinkblue.vw.com/tdi-academy-clean-diesel-vs-gasoline...

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