Why Diesel???

[john_bud]

As much as I distrust "consumer distorts", I am surprised that they listed that. Maybe they are getting a bit less enchanted with Japanese products?

 

[Renze]

I bought a tractor in a southern province. I reset the mileage meter when i left. I had been doing 220 km with empty trailer, and 220 km loaded with a 1800 kg tractor, and drove 100 km/h on the highway. When i got home the meter said i'd been driving 9.5 km per liter... If i had a gasser, i would have used that fuel even without pulling a trailer...

9.5 km per liter would be about 22 miles to the gallon. Car is a 1996 Volvo 850 2.5 TDI, and the trailer was (off course ) a Doornwaard DPW 3500kg mid axle tandem on ultra low 12" balloon tires.



About reliability, some newer technologies, and totally new developed engines cause problems. Wait till the gasoline engines get a new design from scratch, and see how reliable those are...

 

[mjncad]

About reliability, some newer technologies, and totally new developed engines cause problems. Wait till the gasoline engines get a new design from scratch, and see how reliable those are...

That's why the advice is never to buy software with a release number of 1.0 or any vehicle in its first year of production.

 

[RobertN]

About reliability, some newer technologies, and totally new developed engines cause problems. Wait till the gasoline engines get a new design from scratch, and see how reliable those are...

What I found interesting, is that at least here in the States, all the cars and pickups have recent engines from scratch or close to. And, they don't get that much better mileage than previously.

The newer ones are meeting much tighter emission standards, and have impressive power; maybe they give up power for HP?

Why can't you get a 1/2 ton 2wd pickup with ~25mpg? With 5 and 6 speed double OD trannies and the latest computer control, fuel injection etc?

 

[Z-Michigan]

Robert, my dad would agree with you 100%, and I'm not far behind. He notes that cars have gained 800-1000lbs in the last 15 years for the same size car, and while some of that is safety, it's still true when you compare to very safe cars of the late 80's (SAAB, Volvo, Mercedes). Where is all that weight coming from? As for trucks, all the work seems to be going into the most powerful V8s and diesels with HP ratings comparable to small semis, with little or no work in smaller engines. GM is still selling their precambrian 4.3L V6, for crying out loud, and I don't know of significantly better options from Ford, Chrysler or Nissan. Toyota has a decent 4.0L V6 with modern tech, but it clearly doesn't get lots of attention either. I think 6speed transmissions make a huge difference for trucks by eliminating the axle ratio compromises needed with a 4spd, and should allow a modest V6 to handle large loads as long as you're tolerant of slow acceleration when loaded - seems like a reasonable tradeoff to me. But it doesn't seem like any company is looking to make and sell that option, even though they all have declining truck sales and profits that follow those sales. Weird marketing decision from my point of view.

 

[Renze]

6 speeds are pretty much standard now, in European small trucks (vans)
Still you can only get the full 8750 kg CGVW on a mercedes sprinter with the highest axle reduction ratio. With the lowest reduction ratio, these vans will do close to 200 km/h which means that of the new 2006 Sprinter model, there are already a good number available at wreckyards because of rollovers, drivers losing control etcetera...

The lower hp with a 6 speed: Off course there's a reason that semi trucks use 13 speed Fuller trannies instead of a 4 speed

Lots of the weight gain in cars, is added airbags, exhaust catalysers, electric window motors, air conditioning with climate control, etcetera.

euro 4 semi trucks use more fuel than euro 1 trucks because the engines run less efficient to lower the combustion temperature, to lower the emission of NoX....


About my previous statement, and comments on it, i'd have to add that i see that as one of the main reason that GM stopped their 2 stroke Diesels: 2 stroke gives better cards in the game to make a low weight, high performance engine because the pistons work at every crankshaft revolution.
But because 4 stroke technology was more commonspread, they dropped the 2 stroke diesels as the 4 stroke technology was more refined and more knowledge was available from other sources.

I personally, if i was a millionair and only had to work filantropically to serve the world, and not earn an income for myself and possibly a future family, i would have been experimenting with a 4 stroke diesel. well, that would be basically a 2 stroke engine, which uses an extra compression and work stroke, at which water is injected, to extract the last bits of thermal energy in the hot gases by steam power.

Some inventor already made an engine with internal cooling, based on a 4 stroke engine, which became a 6 stroke engine. search Wikipedia for 6 stroke engine

 

[Rara Avis]

The lower hp with a 6 speed: Off course there's a reason that semi trucks use 13 speed Fuller trannies instead of a 4 speed

Where you been? Eaton Fullers are now 18 speeds...

 

[cp1969]

But the trend is toward fewer gears in Class 8 transmissions. Lots of 7 and 9 speeds; Mack used 5 speeds for years (may still for all I know). It had to do with the useable torque range of engines getting much wider. In the old days, with only a 200-300 rpm range of useful torque, many gears were required. With a wide torque range, you don't need all those gears.

 

[Rara Avis]

But the trend is toward fewer gears in Class 8 transmissions. Lots of 7 and 9 speeds; Mack used 5 speeds for years (may still for all I know). It had to do with the useable torque range of engines getting much wider. In the old days, with only a 200-300 rpm range of useful torque, many gears were required. With a wide torque range, you don't need all those gears.

Mack 5 speeds used to make up for it with a three speed auxiliary transmission with a separate shifter...many a guy got the famous forearm bruise using them, when they reached thru the steering wheel to shift the auxiliary transmission shifter while shifting the 5 speed transmission at the same time and have a front wheel drop in a pothole which jerked the steering wheel and thus the forearm bruise...

80,000 lbs on the I-70 in Colorado will definitely benefit having more than 9 speeds...even with today's diesel engines...

 

[rback33]

I am not sure how this has spun this way, but you can get EF's in 13 or 18. I personally prefer the 13, but I spent the most time driving those. If only it were not for the 4:10 rear end I had... I could get to 60 dang fast though, after that...OTOH, a LOT of today's big trucks have automatics in them. Never driven one, but have seen a ton of them roll through our plant. I have no clue now many speeds they have or how they are geared. Oh... and I still have my Diesel.

 

[Renze]

Where you been? Eaton Fullers are now 18 speeds...

I've been in Canada 3 years ago. my cousin converted a semi to a grain box farm truck, which had the eaton 13 speed.

In Europe, Volvo uses only 12 gears in the latest generations of transmissions, instead of 16 like they had 10 years ago.
It has 2 reasons: They needed wider gears to bear the new FH16 660 hp and 3000 Nm, and because of this power overkill, they didnt need as many gears anyways...

I think its a european trend to go towards 12 speeds again... But for special tasks like heavy haulage and dumptrucks, i'd want more than just 12.

 

[Renze]

In the old days, with only a 200-300 rpm range of useful torque, many gears were required. With a wide torque range, you don't need all those gears.

I agree, but on the other hand, the fuel consumption is a hot item too. more gears make it easier to keep the engine operating at its "sweet spot" rpm wise, at any given road speed.

 

[cp1969]

Yes, Mack made some 5 speeds backed by a 3 speed. They were called Triplexes, IIRC.

But they also made straight 5 speeds. Five gears, no auxiliaries, no three speed rear ends, nothing. And they pulled quite well--I can attest to that from personal experience.

 

[rback33]

Yes, Mack made some 5 speeds backed by a 3 speed. They were called Triplexes, IIRC.

But they also made straight 5 speeds. Five gears, no auxiliaries, no three speed rear ends, nothing. And they pulled quite well--I can attest to that from personal experience.

LOL I am not sure I would go THAT far, but they did work. Craziest thing about those was engaging the PTO on them.... As I recall, the gear shift was actually in reverse....

 

[RobJ]

I will say I didn't read all 4 pages, but as a poster on the first page mentioned, there are the "old" diesels and the "new" diesels. Know a couple with the new 6.4. Mileage dropped WAY down. Both had 7.3 before and never got the mileage claimed by some...18, 19, 20? On the highway one new 6.4 got 14.5 empty. Heck my v10 in a CC LB 4x4 gets 12 on the highway, 10 in town. Not to mention the 6.4 is a near $7000 option and diesel is 40+ cent more a gallon. Most guys don't tow that heavy anyway, I don't.

On the Fords the word is "regen". I think the Cummins is doing the same thing. Just dump fuel on the piston on the exhaust stroke to burn the wastes every now and then.

On my truck forum there are some going gasser because of some of these factors.

I'm still driving my 99. I can't afford a new gasser or diesel. :d

 

[cp1969]

LOL I am not sure I would go THAT far, but they did work. Craziest thing about those was engaging the PTO on them.... As I recall, the gear shift was actually in reverse....

On the ones I used, the PTO was air shifted and the transmission was in neutral.

 

[Rara Avis]

Yes, Mack made some 5 speeds backed by a 3 speed. They were called Triplexes, IIRC.

But they also made straight 5 speeds. Five gears, no auxiliaries, no three speed rear ends, nothing. And they pulled quite well--I can attest to that from personal experience.

Well all of our Macks hauling 38' Raven Dump Trailers were Triplexes...Never saw just a 5 speed Mack road tractor...

 

[rback33]

On the ones I used, the PTO was air shifted and the transmission was in neutral.

AH how lucky you are. The very short time I ran one of those I was paranoid I would get in a hurry, skip a step, and throw the truck into motion while hooked up to load or unload. The paranoia kept it from happening, but I was THRILLED when my truck was fixed..

 

[Mahana79]

Back to the original question..............Why diesel?????


i will probably never own another gas vehicle.

i choose Diesels for the economy and torque.

My vehicles:

05 Duramax i get 18-20 empty, 12-14 towing, not bad for an 8,000 pound truck. Can set the cruise with 14.000# behind me and never think twice. i have ~45,000 miles and the only problem i have had was a bad u-joint. replaced it myself for a cost of $12. i do UOA's and have stretched my oil change interval out to 10,000 miles using plain ole Rotella T 15w40. I have done a whoping 4 oil changes. It cost me about $30 for an oil change. Fuel filter every 15,000 miles. For me the diesel makes for a heck of a cost savings.

had a 99 3/4 ton Chevy with 5.7, I was lucky to get 17 on the highway empty and if i even towed an empty trailer it dropped to 8. forget setting the cruise with a 14,000 pound gooseneck behind ya.

My 02 jetta i bought used with 70,000 on the clock. 48 MPG and i have 140,000 on it now. have done timing belt and associated parts ($550) Cam and lifters, alot of 02 TDI's had some bad cams($320). had a coolant sensor go bad and a brake light switch. $32 in parts and fixed. run Rotella 5w40 syn for 15,000 miles with UOA and again about $30 for an oil change

then of course the normal wear and tear items on both, tires shocks/struts, etc.

Oh and since i make my own BioD then it really is a no brainer

 

[RobJ]

Back to the original question..............Why diesel?????


i will probably never own another gas vehicle.

i choose Diesels for the economy and torque.

It's hard to say economy these days. Factor in a near $7000 option on the Ford and diesel running about $.40 more per gallon these days, and the new emissions cutting mileage, if you factor in the price per mile it'll take years and well over 100,000 miles to just break even. And it's hard to justify all this for the average guy to tow an atv on a 4x8 trailer a few times a year. Or driving those heavy kids to school.

Just say...

I'm rich and can afford what I want or
I tow heavy ALL the time.

I can deal with that argument.

Here's the simple math...

Gasser gets 10mpg, gas at $2.60, price per mile $.26 per mile
Diesel gets 14mpg, diesel at $3.00, price per mile, $.21 per mile

difference, $.05. $7000 option for diesel divided by $.05 and that's 140,000 miles to break even.

And we'll not factor in the more costly oil changes, filters, financing the extra $7000 for 5,6,7 years these days, more insurance costs on a more expensive vehicle. And lets hope nothing goes wrong, you know shop time is usually more expensive for diesels. Yeah, this argument has been going on for a while.

Hold on, gotta check those Lotto numbers again...nope, still keeping my 8 year old gasser. shucks.