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Comment by junto | Hacker News Reader

I'd be interested to know what the US public opinion was on diesel engines before the scandal.

British opinion on diesel was really positive and I know lots of people that purchased diesel engined vehicles when (to my knowledge) they were unsuitable for the type of driving those people were undertaking.

In Germany, people will not buy a diesel if they are mostly driving short trips. It is common knowledge (here) that the air filters on diesel engines need time (~15 minutes) to properly warm up to be able to burn off the soot in the filter. Therefore, only the traditional fleet cars who are driven by salesmen driving long stretches on the Autobahn tend to buy diesels.

Was this also the same in the US, because many of my friends that own diesels in the UK had never heard of this?

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The US conventional wisdom is that diesels are big, very dirty truck engines. The small turbodiesel is not a thing that made much headway here outside of a small segment of VW's itself smallish customer base. 18-wheel big rigs, trash trucks, school buses, and passenger busses, on the other hand, are ubiquitous - and emissions on them only minimally regulated until recently. Most people wouldn't know anything about air filters on diesel engines, much less adjust consumer behavior to compensate.

There's also this:

http://www.businessinsider.com/why-diesel-costs-more-than-ga...

You might be interested in this great New York Times aricle (PR piece) for the VW/Audi "TDI" engine that they were marketing heavily a few years ago, long before the current mileage/emissions scandal: http://www.nytimes.com/2013/07/21/automobiles/efficiency-imp...

It goes into the public's views on diesel over time. The article actually was discussed on HN too: https://news.ycombinator.com/item?id=6079973

I can't speak to the public as a whole. But in my circles, there was a lot of interest in the TDI's and similar. With the lower sulfur diesel widely available, there wasn't a perception of VW style diesels being worse than an ordinary car. And the gas mileage made them very attractive. Almost hybrid levels of MPG without the drawbacks of hybrids. And also considered an decent substitution until Tesla, or other electrics, finally become affordable.

I personally almost made a very bad decision. The Jetta TDI was on my shortlist when I was shopping for cars in late summer. Had my GF not disliked it, I probably would have ended up with one.

Only speaking for myself. I owned both a 2010 Golf TDI and 2013 Beetle TDI. I had the Golf because at the time I needed something with four doors and carry capacity but didn't want a CUV/SUV and the diesel was a good deal. I had the Beetle as a TDI based on the Golf experience and wanted a convertible with good mileage.

To be frank, I went with the diesels because the mileage was very good just looking at the EPA numbers which are when the emissions system is supposedly working. At first I was worried about smell but the only smell I encountered was the fuel itself.

I have no problem buying another diesel should it fit my needs at the time. Yet the advances in gasoline engines more than make up for the advantage diesels have. I know with my 4cyl turbo Z4 I am getting sufficient mileage (32 lifetime, 40 on pure highway) that I have no reason too go back.

Now for larger vehicles the mileage improvement is about the only way to go; that being pickups and SUVs. There really aren't any hybrid trucks about and the few SUVs that are do work but diesels seem to offer better highway.

If diesel drivers had to smell what it is like to drive behind one they wouldn't be able to sell any.

Ever driven behind a 2-tact otto bike?! Now that's a smell.

Old diesels were filthy. Modern diesels are not filthy and were momentarily the "king of high tech" until the hybrids came along and dethroned them.

Much as the anti-electric car (paid?) brigade goes nuts about how every red blooded american needs to drive more than 500 miles without taking a break or else the car is totally useless for everyone and will never sell, the anti-diesel people living in Florida will rant and rave about how hard it is to start a diesel engine in -30F weather with a nearly dead battery. There's an american tradition that you never replace your starting battery until it literally 0 volts and won't start the car at all, no matter how annoying it is or expensive tow trucks are or how expensive it is to burn out starter motors or how inconvenient; given that, the user experience of the last 1/3 or so of battery life for diesels is much worse than gas cars.

Another common stereotype is euro car replacement parts are just like detroit replacement parts coming from the same factory in China yet mysteriously the euro car parts cost 3 to 10 times as much. Note that its not true, BMW brake rotors cost the same as Lexus brake rotors, but it is a common perception.

"Old diesels were filthy. Modern diesels are not filthy and were momentarily the "king of high tech" until the hybrids came along and dethroned them."

Maybe, but even the nicest, newest diesels are still aesthetic abominations.

I just walked past a gleaming brand new porsche cayenne diesel and it sounds like a chitty-chitty-bang-bang set piece.

If you're a sound designer and you need to evoke low-tech, rattle-trap primitives, you could do a lot worse than just record a new diesel porsche/bmw/audi.

Also, vibration, as compared to similar gasoline engines (and this is also true for the diesel-like gasoline engines that utilize things like TFSI ... much more vibration than the corresponding non-TFSI engine).

I'm surprised that diesel hybrid automobiles did not become a thing.

If diesel hybrids were superior to gasoline hybrids, they would already be a thing.

As it stands, diesel engines are fairly incompatible with hybrid technology. The primary driver for fuel economy improvement with a hybrid is the ability to turn the engine off for periods of time. Diesel engines do not handle start-stop very well, as they are much more temperature sensitive. Other optimizations, such as Akinson cycle engines, also cannot be applied to diesel engines with any benefit.

Diesel fuel economy shines the most on the the highway. But highway fuel economy for a Prius is already quite good. It's unlikely that you would find a diesel hatchback of its size that returns better highway economy from the same amount of HP.

There's really nothing to be gained from a diesel hybrid.

They brought them because you get much better mileage from diesel and remember the EU has much higher fuel taxes than the USA.

Additionally the tax system was adjusted to make diesel engined cars more appealing.

In the 1970s, General Motors (possibly irreparably) ruined the market for diesel automobiles in the USA. Their offerings were so bad that outside from a few buyers who educated themselves, nobody would touch diesel cars for decades and even now that "common wisdom" has been passed down from older generations.

I can't speak for everybody, but where I am in the US diesel means torque at the low end more than high RPM speed. It's used more for largerish farm trucks and real-work vehicles. It's for when a gasoline engine can't easily get big enough.

Dodge sort of* broke open light truck use when they offered a Cummins turbo diesel with ordinary sized pickups in the early-mid 1990s.

Prior to that, you needed to pull something to justify a diesel engine. Ford sort of numbers their trucks F150/F250/F350/F450 and diesel started being more of a thing about the 350 range. Some of these had dual wheels and what we call a "fifth wheel" setup - there's a largish plate oriented haul hitch in the middle of the bed for pulling cattle and horse trailers, heavier equipment.

*sort of - you'd find all the makers offering diesel in fits and starts through the years. So individual counterexamples abound.

Some people arbitraged the lower price of diesel for a while, but a few years back, diesel became more expensive than gasoline per mile.

I'm in Canada, which is slightly different but similar. Other posters have pointed out the large amount of dirty diesel trucks (and trains). VW's TDI engines have had some recent success. I own a 2012 Jetta TDI because I commute 56km each way for work, so the 5.8l/100km I get from it (80% highway 20% city driving) is handy, and it's fun to drive.

I understand in the US diesel is always more expensive than gas. Here that is only the case in the winter. In the summer it is 5-10cents a litre cheaper than gasoline. In the winter it's about 5-10cents a litre more expensive, the reason I have been told is the demand for diesel oil increases due to furnace oil consumption, which is basically diesel oil.

There are quite a few TDIs on the road where I am, but I live rural so there are a lot of highway drivers. They don't make much sense as an urban car, for stop and go traffic the fuel economy isn't good at all.

Very few diesel cars in the US but an unhealthy amount of diesel pick-up trucks used as commuter vehicles.

This bears repeating, and I think may be quite unbelievable to Europeans:

Think of the biggest, most powerful truck (lorry ?) you've ever seen ... big enough to tow, for instance, 4-6 horses in a trailer, or a 30 foot boat.

Lots (and I mean lots) of normal, private citizens drive these vehicles as their normal commuter cars or to run errands, etc., unrelated in any way to business/work. It is not uncommon at all. A lot of these are indeed diesel.

Also the vehicles (for private, non-business use) are preferentially taxed.

> Lots (and I mean lots) of normal, private citizens drive these vehicles as their normal commuter cars or to run errands

Most of those people use the truck part of the time for tasks that only a medium-duty truck can do, such as towing a boat or trailer, horses etc. They just aren't wealthy enough to dedicate the truck to that single purpose so it is also used as a "daily driver".

> Also the vehicles (for private, non-business use) are preferentially taxed

I'm not aware of any such tax advantage, at least where I live (TX). Diesel fuel is taxed at a significantly higher rate than gasoline. There were (still are?) some IRS deductions for business use of expensive trucks/suvs but that doesn't fit the case you've described.

disclaimer: I own a 3/4 ton diesel pickup used exclusively for private trailers hauling

I'm not sure about most. I know plenty of people who own no such things but still have the trucks.

You probably also know plenty of people who have mustangs, or chargers, or italian sports cars. There's always going to be some folks who just want to play with power. None of them make any sense from a marginal utility point of view.

> They just aren't wealthy enough to dedicate the truck to that single purpose so it is also used as a "daily driver".

They might be better served by doing the math, and realizing that they are far better off buying an economical vehicle at a much lower price point and for much lower maintenance and fuel costs, and then renting a heavy duty vehicle to tow their boat the few times a year they actually need to.

One should optimize for the most common use case.

The trouble with that idea is that it is very difficult to rent a heavy duty vehicle for towing. Most rentals explicitly disallow towing or other types of heavy usage.

I own a Toyota Tundra for those times I needed to tow, but am trading it in for a Model X (5000 lbs towing capacity).

If you can point me to someplace that rents 1 ton pickups with 5th wheel hitches for short-term (1wk-1month) rentals I'll be very grateful.

"Most of those people use the truck part of the time for tasks that only a medium-duty truck can do, such as towing a boat or trailer, horses etc. They just aren't wealthy enough to dedicate the truck to that single purpose so it is also used as a "daily driver"."

And I see plenty of trucks with nice big tires, dual rear wheels that don't even have a tow-hitch _installed_, let alone a turntable.

Google "Section 179 deduction". You can write off the entire purchase price of a truck in the year it was bought if it's heavy enough (>6000 lbs) and the bed is long enough (5.5 ft minimum, 6ft preferred).

It has to be for business purposes, but as always, the IRS is lax in verifying that.

I wanted a diesel vechicle, but heard a long time ago, probally a myth, that small diesel engines don't last very long. It never made sence though because we all know large diesel engines last a long time.

They are not marketed here.

It's hit or miss on finding a gas station that has diesel, but that has definetly changed over the years.

Actually, if I could put 300,000 to 500,000 miles on a small diesel engine, I would buy one. Twenty years ago I would be happy if a vechicle lasted 100,000 miles. I had a Toyota with a 22r engine that spoiled me; I now expect all vechicles to easily last over 250,000 with nothing but oil changes, and new brakes.

Modern small diesel engines will last a long time, provided you adjust your driving style and habits.

There's awfuly many things, that can go wrong, if you don't consider how the engine works - i.e. your turbocharger, DFP, double-mass flywheel - they are subject to physics and you must know, what you can do with the car and what you can't do, to maximize their lifetime.

Do you have any specific advice? I have a small turbodiesel whose life I'd like to maximize.

Turbocharger - don't turn the engine off immediately after stopping, leave it running for a few seconds so the turbo has time to cool off. After starting, don't rev past 2k RPM until the engine oil had time to get into the turbine so it's not running dry(so not for a few minutes).

DPF - don't drive in the city :P if you do, take the car out on the motorway every few weeks at least and maintain speed above 50mph so the car can burn out the soot in the filter.

Double mass flywheel - well, it's designed to absorb the "shock" of attaching the clutch too early. So if you're driving a manual, be gentle with the clutch and your flywheel will serve you well. If you rev your engine and just release the clutch the flywheel will have to absorb a huge amount of force - it's designed to do that so it shouldn't be too harmful, but do it enough times and it will split and have to be replaced.

Drive it like you just stole it. Change the oil every now and then, and keep a clean air filter in it. If it is a TDI or Mercedes, expect to have to pull the intake plenum every 100k miles or so and clean the gunk out of it.

Edit: PS Also, do the timing belt maintenance if/when applicable

PPS: R&R the glow plugs every 50k or so. You may even be able to re-install the old ones (test them first). This is mainly to prevent them from becoming seized to the head, necessitating an expensive repair.

gambiting has the right advice.

I would just add, that:

- the few seconds to cool down the turbo is about 30 to 60. Depending on the ride you just had. Just listen half a song more on your stereo ;)

- DPF needs cleaning every cca 700 km (but really depends on multiple factors). You either have a control light, that will let you know, or you notice a sudden fall in distance-to-empty, because that fuel is being used to burn out the filter ;)

Basically, even if something breaks there, it is still possible to repair it. However, it can be expensive (1000+ EUR for DPF or turbo, again, depends on the car).

20-30 years ago when I was a professional auto mechanic, I would routinely see diesel VW Rabbits that had 250K miles on the clock.

Sadly, the POS VW diesel that I bought didn't last nearly that long. What a steaming pile that thing was. So YMMV.

My dad used to refer to VW Diesels as VW Desmells

Personal impression based on my friends commons on car buying recently. I think electric cars are going to eat whatever small market share diesels have in the US. Also of late diesel fuel is more expensive than gasoline at least in the bay area.

From what I have heard in my country (Poland) most people prefer diesel because it's just cheaper. Naturally it's about the fuel, as the car itself is usually a bit more expensive.

Usually only people who care about performance choose petrol engines.

Most people I know in US consider diesel dirty.

Our experience is with unfiltered, sooty heavy vehicles emitting large visible clouds, due largely to trucking industry lobbying. For decades, this has been normal here. Just recently, CA passed actual emissions standards that apply to heavy diesels but exempt emergency vehicles.

http://forcechange.com/1141/california-passes-toughest-diese...

I cannot wait until buses, delivery trucks, and other urban-driving large vehicles are electric.

http://www.transportation.anl.gov/pdfs/B/855.PDF This is a surprisingly approachable analysis (albeit already almost 5 years old, it seems fairly accurate (n.b. not in industrial battery production)). 20 pages on what it takes in energy to produce the precursors (primarily lithium carbonate), then what it takes to manufacture the actual cells, followed by an analysis of what we can recycle from cells which no longer hold a charge. I'm not saying fossil fuels are the way to go, but if you're driving around a Tesla in Nashville, odds are you're burning a boatload of coal in the process to get your charge from the regional power plant (blowing off the tops of mountains in the process to get that goal).

The paper you link seems very bullish on batteries. (“... we estimate that the energy use and greenhouse gas emissions associated with battery manufacturing make up only a few percent of a plug-in hybrid vehicle’s total life-cycle energy use. Further, the recycling of battery materials can potentially significantly reduce the material production energy.”)

Battery cost is still dropping at an exponential rate while energy density continues to rise. Likewise solar panel costs, and installation (especially at utility scale) is also coming down in price as the industry learns.

I’m no expert, but I predict that within 10 years it will be entirely practical (and much more environmentally friendly than diesel/gasoline, especially w/r/t urban smog) to have bus fleets, delivery trucks, etc. running on batteries.

A software person would say that moving to EV's has the important benefit of separation of concerns.

If power generation is not in the vehicle, our national fraction of combustion generators can be reduced systematically. This is already under way; some US cities are already at 0.

That leaves storage on vehicle. The more EV's we have, the more incentive to find clean, high energy density batteries. This is not a static field either. Graphene is just one vaporware which might appear on the street shortly.

True, but this overlooks transmission inefficiencies. Inherent in moving power over distances is power loss (without superconductors). In that sense, local power generation is superior.

However, my understanding of the overall picture is that car engines (both diesel and gas) are so much less efficient than a power plant, that even with transmission, it's cleaner to switch to centralized power generation.

Gasoline also has large transportation inefficiencies. Unlike solar, every garden a refinery and oil well is impossible while every roof a solar pv is possible, even if 100% unlikely.

Are those inefficiencies actually so large? As they say, liquid hydrocarbons are a remarkably efficient method for keeping large amounts of disposable energy in a vehicle, currently difficult to match with e.g. batteries. And conversion of other energy forms to electricity involves some significant losses as well.

Line loss in US in 2007 was estimated to be 5% in 2013 (http://www.eia.gov/tools/faqs/faq.cfm?id=105&t=3)

For gasoline the number is supper tricky to determine. So here comes a back of napkin number

A fuel truck transports about 30,000 gallons (20,000-40,000). On average they achieve about 4-7.5 miles per gallon). So they use about 1% of their tankage for every 60 miles traveled.

This suggest to me that transportation loses for gasoline are in the same ball park number. Distribution and marketing is often claimed to be about 5% of the total, but I don't know where that number comes from.

All in all the difference is probably not that large, and I suspect the electricity one will drop faster than the gasoline one due to interconnect upgrades.

Our experience is with unfiltered, sooty heavy vehicles emitting large visible clouds, due largely to trucking industry lobbying.

Every week while going to work, I'll see at least one truck belching black smoke while accelerating, due to poor maintenance. I look forward to the day when all the trucks have to have periodic emissions testing like the cars do now.

That's not due to poor maintenance in a lot of cases these days.

Google 'Rolling coal'.

Sigh. I didn't know that was a thing. How obnoxious.

Anyway, mostly it is construction and semi trucks I see blowing black smoke. Usually they are really rusted out anyway, hence the lack of maintenance comment.

The EPA started really tightening up diesel emissions in the late 90's. The big jumps came with particulate filters in 2007, and urea injection in 2010.

Urea injection by the way, is the technology that VW decided to cheat instead of use.

The unique thing California has done is to require all vehicles be retrofitted with particulate filters.

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