Diesels get great fuel economy, but on days like today they don't run

[ThomWV]

Diesels powered vehicles get better fuel economy than their gasoline powered counterparts and with advent of turbochargers their drivability improved to the point they became widespread, particularly in europe. If you haven't driven a vehicle powered by a diesel you might be pleasantly surprised. The do suffer from a problem a lot of people don't know about though. Days like today bring it home for us diesel drivers. First off the colder it gets the harder they are to start but right down just a bit below 20 or so degrees the problems gets worse. The fuel turns to jelly when it gets cold that cold and jelled fuel won't pass through fuel pumps. Dead in your tracks, the things won't go anywhere.

As more and more of them are built and find their way onto the roads I thought this is something more folks should know about.

[DJ13]

1. How do those truckers on "Ice Road Truckers" in N. Alaska do it?

They drive in far colder conditions than you mentioned, there must be a way to do it.

[DCKit]

2. Heated fuel lines.

Not a huge cost, but will add to the cost/vehicle.

[DJ13]

4. That makes sense

I really didnt know, thanks!

[ThomWV]

3. They never shut them off and warmed excess fuel recirculates to the tank

So if you've got one running and it gets cold you can keep it running forever because it heats its own fuel, but if you ever shut it off and let the fuel cool down then it jells up and you're stuck.

[B Calm]

19. We put diesel fuel additive in our tanks. We also plug in our trucks

when they're in the yard.

[NutmegYankee]

5. Don't they add anti-jelling compounds to the fuel?

I thought you could winterize it and add compounds to prevent the jelling?

[ThomWV]

8. I haven't found one yet that does much good

Particularly since they switched to ultra low sulfur fuel it jells at relatively warm temperatures. Mine (Ford with an International engine) is worthless below 20 degrees. Mine will generally start and run about a mile before it quits. The way the system is laid out and how it works allows mine to start if the engine has been artificially heated - which means I plugged in the block heater. That's because the high pressure pump at the engine can push some of the jell through the injectors. However the actual fuel flow to the engine is controlled by a low pressure pump and it simply can't pass the stuff through the lines/filter/water-separator. The bottom line is I can get it started but if I drive off I'll get about a mile and a half and it will die.

So if I can get it started at the house I'll usually just let it set and idle for about a half hour before I try to drive it anywhere. And that's on a 20 degree day. Days like today (high of 8) there's no reason to even go out and look at it.

[doc03]

18. We have a backup diesel at work that may run once a month

or less and I have fired it up on days like today 4º without a problem. There are diesel fuel conditioners and engine block heaters available.

[liberaltrucker]

6. Use D-1 fuel or an additive to lower the cloud point of D-2

I used to run the Northern Tier in winter. It gets
a bit nippy in MN, SD and MT this time of year.
D-1 clouds at -30F and an additive like Power Service
can lower D-2 to that cloud point. I never had a
fuel-related problem in those conditions.

[johnaries]

9. Yep! I work for a "3rd party billing company" for Transportation

most of our customers in cold weather use either #1 Diesel ("Premium" Diesel) or fuel additives or both. In fact, our Custoemr Service has standing orders that in cold weather if a driver for a customer that normally restricts the use of D1 purchases D1, to automatically override the restriction so as not to needlessly delay the driver.

[liberaltrucker]

10. My employer at the time would

automatically authorize D-1 if we ran I-70, I-80 or
I-90 between Dec 1 and Mar 31. It was driver discression
as to whether it was needed. No questions asked.

[johnaries]

11. Some are more trusting of their drivers than others, but this is one

area none of them seem to have a problem with when it's cold.

[Davis_X_Machina]

7. 74% of new car registrations in Norway...

...in 2007 were diesels (PDF file).

What gives?

[Strelnikov_]

12. Mine started and ran fine yesterday at -20F

I use a block heater to ease the start in cold weather. Less wear on engine and battery.

VW TDI's recirc the fuel back to the tank. But, of course, this does not help from a cold start.

I add Standyne Performance Formula to lower the cloud point in the event the supplier did not have properly 'winterized' diesel. This product is recommended by VW for extreme winter use, so it probably works.

Last winter got to -32F. When I started the car a few days later at -12F no problems.

Never had a gelling problem since using Stanadyne PF.

http://www.fueladditiveonline.com/pdf/vw_approval.pdf (.pdf)

[bfarq]

13. Chicken and egg problem

Diesels can burn just about any flammable liquid. The gel problem is a question of formulation. Considering that 99.99999% of the diesel fuel in the US is used by over-the-road trucks that have other counter-measures, there is no market incentive to reformulate fuel.

It really is a chicken and egg problem. Diesels are more efficient than gas engines by a significant margin. The noise and emissions problems have been essentially solved. The only real drawback to diesels is slow acceleration. They have loads of torque, but rev as easily as gas engines. This was a drawback in the past, but it is actually an ADVANTAGE in the world of hybrids. This is because hybrids can rely on the electric motors for instant acceleration.

Take the Prius for example. It gets its best economy in city driving where the electric motor can be used very heavily and wind resistance is not too significant. Once you get up to highway speeds, the electric motors don't do much good and fuel economy becomes a function of the gas engine versus the wind resistance, which increases exponentially with speed. One is hard pressed to get 50 MPG on the highway. With a diesel, the same arrangement would probably get 75 or more. You have to discount that a little because diesel fuel has more energy per pound than gasoline. But it is still a big net gain.

It is even a stronger case in a serial hybrid like the Chevy Volt because diesels are most efficient at a constant speed of relatively low RPM (say 2200). This is EXACTLY what is needed for the engine component of the Volt. Even with gas engines, the GM designers run the engine at constant speed.

So why is the rest of the world adopting this technology while the US resists?

I'm afraid I have some bad news. We aren't nearly as smart as we think we are. The rest of the world is passing us by and we need to insist that our leaders make turning this around a top priority.

[glitch]

14. Very interesting post, welcome to DU! nt

[Midwestern Democrat]

20. Diesel powered automobile engines had a very bad reputation in the

US in the early to mid 1980s - basically, most anyone who was of driving age during that time is very leery of ever buying one - I knew a couple of people who bought diesel powered Oldsmobiles in the 1980s and both of them deeply regretted having bought one. Enough time has passed that the US consumer might be more receptive to diesel engines but I'll admit I'd have to do a lot of research before I would consider buying one.

[bfarq]

21. That is true, but

It was also true in Europe, yet they have gotten way past that point. The attitudes would change very quickly. These things work GREAT. The problem is that the US car companies became so comfortable operating a certain way, they turned off their brains -- and it killed them. And when you have GM, Ford, and Chrysler all three brain dead on this issue, then Toyota doesn't see a reason to blaze that trail. besides Toyota already had their hands full promoting (very successfully) the reason why a person should pay $3K or $4K more for a hybrid, so I don't blame them for not taking this on.

Only Volkswagon has taken this on, and they aren't big enough to overcome the inertia by themselves.
Here's a Popular mechanics article of a couple of years ago.
http://www.popularmechanics.com/automotive/new_cars/4237945.html

Here's an article about the TDI technology.
http://tdi.vw.com/tdi-academy-clean-diesel-vs-gasoline/

What drives me nuts is that the proponents always position this as either/or versus hybrid. That is because they invested in diesel INSTEAD of developing hybrid drives. But in fact the best combination would be a diesel-powered hybrid. But Toyota has the great hybrid system and no diesel while VW has the great diesel with no hybrid system. You would think their ought to be a way to collaborate, but I guess not.

[jmowreader]

24. Diesel powered Oldsmobiles were a nightmare, that's true

They started out with the 350 Chevy. The compression ratio of the Chevy 350 as installed in the 1980 Corvette had 8.2:1 compression ratio. A diesel usually has about 22:1 compression ratio--an engine with nearly 3x the compression needs a much stronger way to hold the heads on, and GM didn't provide it. It also had a chain-drive fuel injection pump (you'd think they could have used the distributor drive) and no fuel/water separator.

The IDEAL way to go would have been to call their Japanese partner Isuzu--a huge maker of diesels--and just had them design one quick, but no.

[ddeclue]

26. That's really not fair though..

Mercedes and Volvo made excellent turbo diesels.

Volkswagon Jetta Diesel w a 5 speed got 54mpg in 1984.

[Jamastiene]

15. That, I did not know.

Interesting thread. K&R

[newfie11]

16. Both our trucks are diesel and we live with-30 weather

First off the fuel must have an additive added and if it is really cold you can run straight #1 diesel. Most of the diesel sold in my area has additive alreaded added but when it is -30 to -30 we add more.

It is possible to have diesels in cold weather. Our dodge ram has never been plugged in and starts fine at -20, our ford will start every time if plugged in but at 0 to 10 degrees it says no with out being plugged in.

BTW the dodge is a 1 ton dooley and we get 25 mpg.

[rzemanfl]

17. I had an '81 Diesel VW Rabbit that got 44 mpg on the highway

and would do 74 mph on a good day with a tailwind and the a/c off. A great little car. I lived in Wisconsin and had a couple of close calls when the temperature suddenly got way below zero but managed to get it home. I didn't drive it when it was much below zero and had a block heater on a timer that went on at 4 a.m. in the winter.

[OnceUponTimeOnTheNet]

22. 16 years ago I had my DH's truck jell on me in 30 below weather.

Coming back home on the highway from a bank seminar from the next town over. One of my fellow crew saw and stopped to retrieve me.
I was wearing a skirt and heels for petes sake. That was pretty stupid.
Now I keep a candle, strike matches, and a coffee tin in both vehicles. Neither of which are diesel.

[jmowreader]

23. Howes Diesel Treat is the stuff for you

This is the shit the Army puts in their fuel at Fort Drum, New York. (It's added to the bulk tank--this is extremely concentrated.)

[ddeclue]

25. There are things you need to do to any engine to winterize it - gasoline, diesel or turbine:

1) Engine block heater plugged in to keep the engine warm enough to start easily.
2) Radiator baffles to reduce cooling.
3) Garaging the vehicle and preheating it.
4) Diesels need glow plugs in winter weather.
5) Using a lighter grade of diesel fuel will keep it from gelling in cold weather so easily.
6) Insulate the fuel lines/fuel tank to keep the fuel from gelling in cold weather.
7) When not garaged: Keep the vehicle running in cold weather. If you can't run it continuously, start it periodically (every few hours) to keep things from freezing up.
8) Using thinner oil in the winter will make it easier to start.
9) Keep the battery charged and put a new one in when the weather turns cold - batteries that are weak have a hard time heating glow plugs and turning starter moters etc.
10) Keep the vehicle well maintained.
11) Replace the fuel filter when the weather turns cold. The cleanest filter will have the best chance of not clogging in cold weather.
12) Run the highest recommended mixture of anti-freeze in the radiator. Water freezing can crack a block or a head.
13) Heating the fuel lines to keep them from gelling.

Doug D.
Bachelor of Aerospace Engineering, Georgia Tech
Private Pilot Single Engine Land