Deisel engines

[GullyFoyle]

What is the deal with Deisel enginse being so popular all of the sudden?

 

[Atty]

It has always been popular over in Europe, afaik. Companies like VW/Audi/etc want to make it more popular here. Our problem, as I understand it, is that the government isn't behind Diesel as it is behind gasoline.

Disel is a good fuel source. Good mileage, engines usually last a long time, decent power. There are trade offs in pure performance and design. I think its gaining popularity because its an already installed alternative to gasoline which would make it easier to be more widely utilized.

 

[LTC8K6]

What is the deal with Deisel enginse being so popular all of the sudden?

They are a little more popular in the US than they were, I think. Still overall not very popular yet.

If our refineries were to adjust their output to produce more diesel fuel, and the price came down, they would be more popular.

The only thing stopping me is the high price of the fuel.

And I am a little wary of the fact that if you run out of DEF, the car won't move.

 

[smackababy]

I think people are just now realizing that their ideas of what diesel engines are isn't true. Most Americans think diesel engines are only like those in big rigs. (big, loud, stinky, and not fuel efficient)


And from what I understand, diesel takes less refining than traditional gasoline and should be cheaper. The reason it isn't is because of taxes from perceptions that it is more pollutant than gasoline, which is based on my previously stated American perception of diesel.

 

[iamwiz82]

The idea of diesel engines in passenger vehicles was hurt pretty bad by GM in the late 70s.

 

[vi edit]

If our refineries were to adjust their output to produce more diesel fuel, and the price came down, they would be more popular.

Isn't there only about 1/2 as much diesel in a barrel as there is gasoline after refining? If there's only half as much supply but you increase the demand I'm not sure that would work out as designed.

 

[LTC8K6]

Isn't there only about 1/2 as much diesel in a barrel as there is gasoline after refining? If there's only half as much supply but you increase the demand I'm not sure that would work out as designed.

I think that is correct, but that may be because our refineries are set up that way.

Also, I think the switch to ULSD means more refining.

 

[LTC8K6]

One barrel of crude oil, when refined, produces about 19 gallons of finished motor gasoline, and 10 gallons of diesel,

http://www.eia.gov/energyexplained/index.cfm?page=oil_refining

 

[amyklai]

Isn't there only about 1/2 as much diesel in a barrel as there is gasoline after refining? If there's only half as much supply but you increase the demand I'm not sure that would work out as designed.

The main reason why Diesel is so popular in Europe is that generally (differs a bit from country to country) fuel is heavily taxed and the tax on Diesel is a bit lower than on gasoline while Diesel at the same time contains more energy per liter than gasoline. So it's mainly a bang for buck calculation that might have different results if Diesel wasn't taxed less.

 

[Mark R]

Diesel fuel has historically been cheaper in Europe due to lower taxes, and as a result there has been a big increase in the market share of diesel passenger cars. That said, some governments are trying to reverse this; notably the UK, where fuel taxes are significantly higher on diesel fuels and vehicle annual registration fees are higher for diesel vehicles.

To an extent, this is due to concerns over particulate emissions. DPFs are now mandatory for all new model diesel cars in Europe. They are expensive and bring a lot of problems (poor fuel consumption, high exhaust gas temperatures, occasional clogging unless regularly given high-speed highway driving, and very high sensitivity to engine oil - use of engine oils with traditional anti-wear and anti-corrosion additives will irreversibly clog the filters due to ash particles produced by the combustion of these additives).

There is also potentially the ongoing cost of regular refilling of the car's DPF catalyst solution. Not all cars use this, but some DPF systems are designed to work with a fuel-borne catalyst (usually cerium oxide nanoparticles), and the cars come from the factory with a concealed reservoir of catalyst which is dispensed into the fuel tank when you fill up. After about 40k miles the reservoir depletes, necessitating a very expensive ($500+) refill.

Similarly, because of the complex emissions systems such as EGR systems, diesel vehicles are generally less reliable than they used to be. Similarly, modern common-rail fuel systems are much more sensitive to fuel quality than they have ever been.

I'm not aware of any passenger cars using urea solution (DEF) for NOx control, EGR is the preferred method in Europe; the use of urea was considered too inconvenient for use by the general public. However, urea is used for heavy trucks, buses, etc; at a truck stop gas station the pumps often have 2 nozzles, one for diesel and one for urea; just fill up both tanks at the same time. That said, even if you run out of DEF, the vehicle will still run, but power will be limited. Urea is purely an emissions thing; it does not effect engine running and lack of urea will not damage the catalyst. (Emergency vehicles like fire and ambulance are often fitted with an override system which will prevent the ECU entering reduced power mode in the event of urea exhaustion; of course, if you grease the right palms, you can get such an override installed on your truck too).

 

[Zenmervolt]

And from what I understand, diesel takes less refining than traditional gasoline and should be cheaper. The reason it isn't is because of taxes from perceptions that it is more pollutant than gasoline, which is based on my previously stated American perception of diesel.

Actually, this is backwards. Diesel is cheap in Europe because it is heavily subsidized through the tax structure. Gasoline in Europe is taxed at vastly higher rates than diesel (due to the fuel efficiency benefits of diesel) which creates an artificially high price for gasoline and an artificially low price for diesel at the pump.

ZV

 

[Vic Vega]

...

 

[boomhower]

I think they are essentially over with for the most part. Sure some new models will come amd VW in particular will keep them going but the prime time for them to grab marketshare has passed. When hybrids offer similar performance for similar price without the downside of diesels I just don't see it becoming a big seller. No need to hunt for fuel, no need for costly add ins for emissions. Just gas and go. One of the big advantages of diesels, life span, are completely lost on 99% of buyers as they aren't going to keep them that long.

 

[LTC8K6]

Diesel fuel has historically been cheaper in Europe due to lower taxes, and as a result there has been a big increase in the market share of diesel passenger cars. That said, some governments are trying to reverse this; notably the UK, where fuel taxes are significantly higher on diesel fuels and vehicle annual registration fees are higher for diesel vehicles.

To an extent, this is due to concerns over particulate emissions. DPFs are now mandatory for all new model diesel cars in Europe. They are expensive and bring a lot of problems (poor fuel consumption, high exhaust gas temperatures, occasional clogging unless regularly given high-speed highway driving, and very high sensitivity to engine oil - use of engine oils with traditional anti-wear and anti-corrosion additives will irreversibly clog the filters due to ash particles produced by the combustion of these additives).

There is also potentially the ongoing cost of regular refilling of the car's DPF catalyst solution. Not all cars use this, but some DPF systems are designed to work with a fuel-borne catalyst (usually cerium oxide nanoparticles), and the cars come from the factory with a concealed reservoir of catalyst which is dispensed into the fuel tank when you fill up. After about 40k miles the reservoir depletes, necessitating a very expensive ($500+) refill.

Similarly, because of the complex emissions systems such as EGR systems, diesel vehicles are generally less reliable than they used to be. Similarly, modern common-rail fuel systems are much more sensitive to fuel quality than they have ever been.

I'm not aware of any passenger cars using urea solution (DEF) for NOx control, EGR is the preferred method in Europe; the use of urea was considered too inconvenient for use by the general public. However, urea is used for heavy trucks, buses, etc; at a truck stop gas station the pumps often have 2 nozzles, one for diesel and one for urea; just fill up both tanks at the same time. That said, even if you run out of DEF, the vehicle will still run, but power will be limited. Urea is purely an emissions thing; it does not effect engine running and lack of urea will not damage the catalyst. (Emergency vehicles like fire and ambulance are often fitted with an override system which will prevent the ECU entering reduced power mode in the event of urea exhaustion; of course, if you grease the right palms, you can get such an override installed on your truck too).

Several vehicles here in the US use DEF and a DPF, iirc. Cruze and Passat come to mind right away. Also the Grand Cherokee.

 

[LTC8K6]

Warning messages for the Grand Cherokee if you run out of DEF

Engine Will Not Restart in XXXX mi DEF Low Refill
Soon
Engine Will Not Restart in XXXX mi Refill DEF
Engine Will Not Restart Refill DEF

 

[LTC8K6]

The Cruze won't stop entirely:

When the mileage countdown is
zero, the DIC message EXHAUST
FLUID EMPTY REFILL NOW -
TRANSITIONING TO 7 KM/H
(4 MPH) MAX SPEED displays.
A flashing warning light and a chime
also come on. Vehicle speed will be
reduced to a maximum speed limit
of 7 km/h (4 mph).

So I guess you'd better not run out of DEF.

 

[LTC8K6]

The engine quitting and speed limits for running out of DEF are from the EPA:

The following actions describe
strategies required by the U.S.
Environmental Protection Agency
(EPA) and the California Air
Resource Board (CARB). The DEF
messages relate to these strategies

 

[Zenmervolt]

I'm sure that there will be plenty of "off road use only" ECU tuners that will eliminate the power reduction from a lack of urea that start to show up once diesels get more common here.

ZV

 

[LTC8K6]

Yeah, ambulances were apparently quitting en route. I think the EPA must have allowed over rides for emergency vehicles since those incidents.

 

[LTC8K6]

I'm sure that there will be plenty of "off road use only" ECU tuners that will eliminate the power reduction from a lack of urea that start to show up once diesels get more common here.

ZV

Wouldn't that clog the DPF quickly?

Apparently not.

 

[Zenmervolt]

Wouldn't that clog the DPF quickly?

Apparently not.

I would imagine that the sort of people disabling the urea warning/shutdown are the sort of people who don't mind removing the particulate filter if there are clogging issues.

ZV

 

[SyndromeOCZ]

Yeah you just remove the DPF. It doesn't take long for the 'off-road' chips to hit the market. Sometimes they are available before you can even buy the vehicle.

 

[thedarkwolf]

It isn't like it is hard to find a bottle of urea and fill the tank back up. They give you a warning a LONG time before you run out.

 

[Mark R]

Wouldn't that clog the DPF quickly?

No. Urea is not used by a DPF, but by a SCR catalyst, if fitted.

Lack of urea won't do anything to the engine or emissions, except temporarily result in increased smog forming emissions (not particulates).

I guess the whole vehicle disable thing must be an EPA regulation. It's not that severe in Europe. I guess the use of urea in passenger cars must also be an EPA thing.