[danjayh]

While I'm certainly not making excuses for VW cheating, I think that maybe the EPA needs to revisit its diesel emission standards. The EPA standard is the strictest in the world, and they have successfully ruined many diesel powered devices. Examples:

1) I was recently looking at compact tractors. To meet the standards, new tractors are fitted with Diesel Particulate Filters. Even if they don't flat-out fail (which happens too often, and costs thousands of dollars to fix), these filters require "regeneration", which is code for "a light comes on on the dashboard, your tractor stops moving, and runs wide-open throttle for 20 minutes while you stare in bewilderment". Google Kubota B3350 Regeneration if you want lots of fun horror stories.

2) Diesel commercial trucks. My uncle drives a large cube van over the road. When his truck goes into regen mode, it doesn't require wide-open throttle like a compact tractor, but it does lose power and tops out at 40-50MPH. If you are on a freeway where the flow of traffice is at 80MPH, this is dangerous and a major problem.

3) Diesel pickup trucks: Many trucks, in an effort to avoid additional hardware above and beyond the DPF, have taken to injecting fuel during the exhaust stroke. The idea is to have the unburned fuel get pumped through the engine and on to the DPF, where it burns and increases the temperature to the point that the carbon burns out of the DPF. Problem is, when you inject fuel into an engine during the exhaust stroke, it dilutes the oil in the cylinder, reduces lubrication, and causes premature wear/engine failure.

In the two cases I am familiar with, diesel motorhomes and diesel compact tractors, the value of used vehicles has increased quite a bit in response to the fact that all of the new ones suck. My Dad owns a gravel pit, and he (along with everyone else in the industry) buys and re-builds existing vehicles from the frame-up to avoid having to purchase new products, which are unreliable, sometimes dangerous, and uneconomical to maintain. Google "glider truck kits" -- it's basically the idea of purchasing all the parts of a new vehicle (except the powertrain), and then manually taking the powertrain from a worn-out truck, re-building it, and installing it into the glider kit. This is often done at an expense that is similar to that of purchasing an entirely new vehicle.

Many equally horrible solutions to this problem are employed. Some designs incorporate a fuel burner directly into the exhaust design. Others require a separate tank of catalytic fluid that must be filled regularly. One thing that all of the designs have in common is poor performance and piss-poor fuel economy. Many vehicles from multiple manufacturers have had trouble with catching on fire due to emissions control systems.

If the EPA wants to make tough rules that will force manufacturers to produce products with the best available technology and encourage development of new technologies, that's one thing. When the EPA makes rules that result in dangerous and/or non-functional product designs, I think it's time to back off just a bit until the technology has come closer to being able to reasonably achieve the regulated cleanliness levels. It's completely insane to make a truck that will force you to slow to 40mph while you're driving it, or to make a tractor that will force a farmer to take an unplanned break in the middle of the day (remember -- farmers work all day long, and daylight is a limited, precious commodity to them).

EDIT: To be completely clear, if you are doing work with the tractor that can be done at full RPM, you don't necessarily need to park it. However, if you're doing something that requires lower RPM (using a PTO attachment that needs low RPM like a post-hole digger, or a spreader, etc ... or doing low-speed work on a tractor with a geared transmission), then it's time to go get some coffee. Personally, the two major things I want to do with a tractor are run a large snowblower and maintain our horse pasture. For the horse pasture it's not a big deal, but if I need to clear the driveway before leaving for work in the morning, an unplanned 20 minute wait is completely unacceptable.

[mikestew]

The EPA standard is the strictest in the world, and they have successfully ruined many diesel powered devices.

One thought, then, is that diesels are not suited to the task. If that particular type of engine can't move things down the road without filling the air with pollution, perhaps it's time we moved on to something else. I mean, what tasks require a diesel? Commercial vehicles, okay. Consumer cars? Not if they spew crap into the air just to save a few MPG. Small farm equipment? See below, totally unnecessary, IMO. Class A motorhomes? Please. The fact that it's designation has "recreational" in the name tells you that kittens won't die if we don't have anymore of them.

An extreme stance? I dunno, maybe. Just like getting rid of lead in our fuel was probably an extreme proposition at one time. But we knew lead was bad, we knew it for decades. But profits uber alles, eh? I just don't know how one would justify to future generations, "sorry 'bout the smog, but Daddy needed to run his garden tractor on diesel, and wanted to save a few bucks on fuel."

I could see an exception for commercial vehicles, but I can't see a good argument for consumer diesels if we can't produce ones that don't choke the air with particulates and NOx.

Personally, the two major things I want to do with a tractor are run a large snowblower and maintain our horse pasture.

Not to pick on you personally, but those tasks don't require a diesel. PTO, plowing a small field, running a bush hog or deck mower, pick your poison, it can all be done just fine with a gas engine. And the gas engine will start when it's -20F and that driveway needs plowed. I grew up in farm country, and the only ones running diesel where the ones with farm equipment the size of your house. I refuse to accept that we'll back off on EPA regulations because some dude feels like he needs a diesel to maintain his five acre play farm. (Again, not directed at you; I have no idea how many acres you have.)

[danjayh]

Prior to the current (Tier 4) standards, the Tier 3 standards had already reduced NOx and particulate emissions to the the point that it's misleading to characterize those engines as "filling the air with pollution". Now that CO2 has been declared as pollution, the improved thermal efficiency of diesels over gasoline engines probably means that they were already "better" than gas under some operating conditions. Even ignoring their superior thermal efficiency, Tier 3 diesels achieved similar results to gasoline engines when both were operated at high load (Say, running down the highway at 80mph). This was accomplished with technologies that, while they added complexity and cost to the engine (such as direct injection, EGR, DOC, VVT, advanced FIE, improved combustion chamber design, increased compression ratio, advances in turbochargers), did not compromise the utility and safety of the device using the engine.

As you have suggested, many manufacturers will probably move back to gasoline engines in some of the smaller applications ... but they will moved to air-cooled V-Twins for many of these, which fall into the same power range as the diesels they replace (~20-40HP). Air-cooled gasoline engines are not clean beasts, and this move will probably actually end up being a net environmental loss.

Have a look at the chart on page 2 of this: http://www.mtu-online.com/uploads/tx_templavoila/WhitePaper_...

The additional NOx reductions achieved by tier 4 are extremely small compared to the cost & trouble caused by the technologies used to achieve them ... the previous tech (up to Tier 3) was fairly reliable & had already achieved most of that was had in the overall journey from unregulated -> Tier 4.

Also, almost none of the garden tractors sold are diesel, because in that application it doesn't make sense - those engines aren't run at high load for long periods of time. However, for a compact tractor that may well be run all day long in high heat with a demanding attachment, a diesel actually does make a lot of sense - there is a large environmental cost to dumping a machine with 5-600 hours on it because the engine gave out prematurely (which happens to entirely too many of the garbage lawn & garden tractors sold at box stores, despite their relatively easy lives).

FWIW, I let my lawn die in the summer and probably mow it fewer times in an entire season than many folks do in a month ... living in the sticks with nobody to judge me has its benefits :) You did get reasonably close on the size, though. My dad and I live close enough together to share a tractor, and we have 26 acres, a goat, five horses, and sundry other critters between the two of us (and our wives, of course).

[kbenson]

> One thing that all of the designs have in common is poor performance and piss-poor fuel economy.

At what point does it become economical to just run gasoline instead of diesel then (that is, manufacturers selling gasoline models)? If we are talking about diesel still being economical instead of gasoline, but just not as economical as when it was allowed to be more polluting, I'm not sure I can muster much sympathy (but I'm fairly uneducated on the subject, so it may just a matter of not knowing enough).

> When the EPA makes rules that result in dangerous and/or non-functional product designs

Did the EPA make rules that required that, or did manufacturers mess up in their attempt to offer the same features as before? Did the EPA dictate this solution, or did the market respond with a poor solution to an EPA requirement on emissions?

[danjayh]

> At what point does it become economical to just run gasoline instead of diesel then (that is, manufacturers selling gasoline models)? If we are talking about diesel still being economical instead of gasoline, but just not as economical as when it was allowed to be more polluting, I'm not sure I can muster much sympathy (but I'm fairly uneducated on the subject, so it may just a matter of not knowing enough).

People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds. They also make more low-end torque, for the same reasons. Both of these factors are extremely important to the types of equipment that you see diesels in, probably even moreso than the problems caused by diesels. For many years, Diesel fuel was more expensive than gas, but people kept running them anyway in the applications for which they were most appropriate. For cars, yeah, we'll probably just see the death of diesel in that space.

> Did the EPA make rules that required that, or did manufacturers mess up in their attempt to offer the same features as before? Did the EPA dictate this solution, or did the market respond with a poor solution to an EPA requirement on emissions?

The market responded with the only solutions it could come up with. The EPA made standards that are impossible to meet using any available technology without causing some or all of the problems I mentioned.

[CydeWeys]

> The EPA made standards that are impossible to meet using any available technology without causing some or all of the problems I mentioned.

I think you're being hyperbolic here in saying that the standards are impossible to meet. What about urea injection? That works pretty well, right?

But even ignoring that, it's not like there's some god-given right to run diesel engines. Either the emissions standards are reasonable or they aren't. That's the only consideration here. If they are reasonable, and most diesels can't meet them, well then too bad, diesel is just an inferior technology. There's alternatives that don't find it impossible to meet environmental/health standards.

[i38608]

I don't think replacing "inferior technology" with inferior technology is a good idea.

[CydeWeys]

I don't follow. What "inferior technology" (in scare quotes) is being replaced by what actually inferior technology? Are you really trying to claim that gasoline engines are inferior to diesel engines for passenger vehicles?

[Retric]

I don't think people / companies really have a 'right' to pollute, so as long as the standards are possible to meet at reasonable costs I don't see a problem.

PS: Low end torque is really just a transmission problem. X(1) power at Y(1) RPM > X(2) power at Y(2) RPM.

[cplease]

> People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds.

This makes plenty of sense for heavy machinery and trucks. This makes no sense for passenger cars, and little sense for most consumer SUVs and light-duty trucks. On any decent modern car a gasoline engine with proper maintenance is the about the last thing to go. How often does a typical car owner rebuild their engine? By the time you get to 200K, a car is typically a money hole for reasons having little to do with the engine. This goes double in northern climates with real winters. By the time the engine needs a rebuild you have a rust-bucket clunker that should be replaced with a more contemporary model.

[w0utert]

>> People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds.

Reliability is one of these stubborn diesel myths that refuses to die. The lifespan of modern gasonline engines -when driven normally- is several multiples of what the average owner will drive the car for before it is replaced. You can easily put 300K kilometers on a gasoline engine before it needs a 'rebuild' (which typically involves not much more than changing the piston rings and rod bearings). Around 150K you may need a mild cylinder head revision (valve seals, valve seats, tappets) if you torture the engine enough. You won't have to break the bank for either of those. I don't know a single person except myself (driving a 25 year old car with a high-performance engine) who ever needed an engine rebuild.

Meanwhile, regular servicing for diesel engines is guaranteed to be more expensive compared to a gasoline engine, so in the long run you will not save any money on maintenance unless you drive your car without any care for reliability.

[sliverstorm]

Of course, gasoline cars went through similar pains in the 70's, and eventually came out better than ever. Emissions controls were really what drove electronic fuel injection [0], which was unreliable at first but far superior to carburetors today.

[0]: See motorcycles, which stuck with carburetors as long as possible, until they were forced to implement electronic fuel injection around 2005 due to tightening emissions standards.

[danjayh]

Very true - regulation undeniably accelerates technological advancement for emissions technology ... I think that the key is just striking the right balance. I was just trying to express that in the case of Diesels, the EPA may have done too much too fast.

As an aside, even when the technology matures and goes from "sucks"->"unquestionably better", all of this is not without cost. New car prices have significantly outpaced inflation in the past few decades. For instance, 50 years ago the base model mustang would have cost ~$18k in today's dollars, and the 2015 base model mustang is ~$24k. To many people a forced 33% increase in the cost of a base model vehicle is not trivial -- this is something that disproportionately effects low-income folks. Since the USA is so spread out, in many areas where population density is low it's basically impossible to get by without a car. (I chose the Mustang because somebody else already did the legwork - source: http://fortune.com/2014/10/17/ford-mustang-cost/ )

In my home state of Michigan, we don't have mandatory emissions testing, which I personally see as a good thing. Cars don't last much longer than ~15, maybe 20 years here anyway due to the extensive use of salt on the roads during the winter, so they get replaced quickly enough with newer/better/cleaner models by virtue of the fact that they rust away. I see a lot of people with cars who couldn't afford it if they weren't allowed to drive beaters. As you may have guessed from my post on shopping for tractors, I happen to live in an area where public transport isn't practical for much of the suburban/metro area (Grand Rapids/Holland), although we do have it (to some extent) in the more densely populated sections of town.

Interestingly, with the revitalization of downtown that's been happening around here, many poor people are being pushed into areas where public transportation is either inadequate, not available, or completely and totally unfeasible (if the houses are 200-500+ feet apart, or the small town has a population of 1,000, it just doesn't make sense).

[sliverstorm]

Mustangs got more expensive, but that's only one data point :)

http://blog.caranddriver.com/are-cars-getting-less-affordabl...

Heavily salted states certainly have an easier time justifying no emissions testing. You start out with a "known good" (regulated by the EPA) and count on cars to expire quickly. Compare to California, which thanks to gentle climate still has a huge fleet of 1980's cars on the road.

[danjayh]

That's about the only good thing about the salt (aside from not dying on an ice patch :) ). My wife's 2005 Pontiac G6 with 120k on it is already starting to rust. I dumped my last car at ~9 years old with ~130k because it was starting to rust.

OTOH, I have a '96 Camaro that I only drive during the summer that doesn't have a speck of rust on it (driving an RWD car in a northern state during the winter is a good way to end up in an accident). It's amazing how big a difference the salt makes ... and dirt roads -- I think they kill cars even faster than salt. We are lucky enough to live on a paved road, so I don't have to worry about that particular problem.

[ghaff]

Yep. I have a '97 Honda Del Sol. I did drive it in the winter some for a while but haven't for a number of years; I live in Massachusetts. Now, whenever it's in at the dealer, I invariably have a mechanic or service manager commenting on what great shape it's in. (It's not in mint shape by any means but it doesn't have serious rust other than the exhaust replacements that it's inevitably had.)

[brohoolio]

My current 2013 Ford Focus sticker price matched up exactly with inflation on the sticker price of the 97 Escort it replaced.

I was kind of amazed given all the safety improvements.

I did get 250,000 miles out of the escort before the salt rusted out too much.

[dsharlet]

On the other hand, if you've ridden a bike with a diesel vehicle in traffic nearby, you'd swear that the EPA was being far too lenient about emissions.

[trhway]

you're making pretty much the same argument that GM did with electric cars some years ago.

>When the EPA makes rules that result in dangerous and/or non-functional product designs, I think it's time to back off just a bit until the technology has come closer to being able to reasonably achieve the regulated cleanliness levels. It's completely insane to make a truck that will force you to slow to 40mph while you're driving it, or to make a tractor that will force a farmer to take an unplanned break in the middle of the day (remember -- farmers work all day long, and daylight is a limited, precious commodity to them).

it is not EPA at fault here, it is truck and car manufacturers who need to get off their a&& and start manufacturing good products. History shows that only tightening of regulation can make them do it. Without tightening of regulations, the manufacturers will be mining the same technology/product again and again...

[devit]

I wonder if it would be even remotely feasible to have an electric tractor for farming use that is powered by a power line attached to a tall pole on the tractor (with a winding/unwinding mechanism as the tractor moves).

[selimthegrim]

I thought that DEF wasn't a big performance killer? (limp mode with low levels notwithstanding)

[bri3d]

The parent poster is talking about DPF (Diesel Particulate Filters), which remove soot from diesel exhaust and require manual cleaning and/or the regeneration process mentioned (where the soot is essentially burnt out of the catalyst).

DEF is a fluid which is injected across a catalyst in a process called SCR (Selective Catalytic Reduction) which is designed to remove NOx from the exhaust stream. SCR (and the use of DEF therein) replaces extensive EGR (Exhaust Gas Recirculation), not the use of a DPF. Catalytic reduction instead of EGR reduces the load on the DPF and increases economy, since dirty exhaust is not being recirculated and combustion is more efficient. However, they're complimentary systems, not replacements for one another.

[selimthegrim]

Yes, I own a VW TDI, I know the difference between the two. AFAIK, EGR adjusts the combustion temperature so as to avoid an overly NOx-producing lean burn. I was responding to the blanket characterization he made in this statement quoted below.

>Many equally horrible solutions to this problem are employed...Others require a separate tank of catalytic fluid that must be filled regularly. _One thing that all of the designs have in common_ (emphasis mine) is poor performance and piss-poor fuel economy. Many vehicles from multiple manufacturers have had trouble with catching on fire due to emissions control systems.