Diesel truck with best MPG

[Mud Mechanik]

Gosh, feel free to tell us more! Inquiring minds want to know. I read in the trade magazines that regular unleaded is sold at cost and the profit is made on the rest of the distillates. And what about the types of fuel oil, i.e., some posters here say ULSD is all that there is anymore but others claim they can get LSD for off-road use. Where is the lubricity added? At the refinery or further down the supply chain?

Finding out about fuel or gasoline is harder than it should be. It's not like it used to be when some retailers were claiming their gas would give you better mileage or 'clean' your engine.

I don't work in the marketing department so commenting on gasoline prices would be a guess on my part. ULSD is the standard fuel spec target, which means that it has to be less than 10 ppm sulfur, if for some reason the finished product tanks test higher than that, it is easier to "relax" the diesel processing units to let the sulfur creep up to convert the entire tank to 500ppm and sell it as LSD (died red), than to fire up the plant and lower the entire tank to less than 10. Since sulfur is the lubrication property of diesel, lubricity is added at the refinery and tested prior to leaving to ensure proper specs, lubricity is only added to ULSD.

I will answer any questions you may have about refining fuels, just point me down the road you want to go.

 

[buickanddeere]

Pre-2007 = Cummins RAM all the way. After that, they all stink...

I would love to take a new diesel truck from any manufacturer making 800lb-ft and de-tune it to the 5-600 needed. I bet it would get 25+ mpg's WITH the emissions stuff.

Would not make a lick of difference. If it takes 60HP to overcome aerodynamic drag, rolling friction and parasite loads. The defined or the higher boost/higher fuel volume version of the se engine still has to make 60HP to maintain cruise speed.

 

[buickanddeere]

Empty MPG really isnt a factor for me, but loaded mileage is... Oil change intervals really arent a factor... I do mine cheaper than most quickie lubes charge for a 5.7L HEMI...
I used to have a 4:10 geared gas truck before the current diesel... not only did I have poor fuel mileage, I had poor pulling performance for the weights I pull. My diesel pulls 10x harder while gettting better fuel mileage...
Does side is repair costs... yes, they can be more expensive... but, I consider that as part of the liability I assumed by needing to pull heavier loads than the gassers can comfortably do.
Just my .02 and I expect change back!

Pulls 10X harder.................explain that factor of 10.

 

[buickanddeere]

As previously stated. Unless your trucks claimed mileage is hand calculated with a known accurate pump instead measuring via the dash fuel tank gauge. And the miles used is from a GPS unit or a known distance instead of trusting the dash odometer. Then the mileage averaged over 10+ tanks of fuel. Don't bother wasting my time quoting the supposed mileage you wish your vehicle is making. How these people keep a straight face and claim mileage that would require diesel to provide 210,000 btu per gallon. Or engines with 55% thermal efficiency ?

 

[TheGoose]

Oh Goody another diesel truck thread.

 

[dodge man]

My early '04 is about 1-2 mpg better than yours, also with 4.10s, but a 6 spd manual. Yours is an early '04 right? The '04.5-'07 trucks lost a bit of mileage due to the cam shape (commonly referred to as the 'in-cylinder egr'), and also the triple shot injectors, compared to two shot in the early common rails.

Yeah, mine is an early 04, the 305 hp motor. Its probably one of the later ones made as the build date is decemeber of 03.

 

[Dmace]

Would not make a lick of difference. If it takes 60HP to overcome aerodynamic drag, rolling friction and parasite loads. The defined or the higher boost/higher fuel volume version of the se engine still has to make 60HP to maintain cruise speed.

It doesn't take 800 lb.ft of torque to move these new trucks, sorry if you don't understand how this power is made but it's pure fuel delivery. Less power equals less fuel. It won't tow 20k lbs as well but in a half ton that's not neccessary...

 

[Raspy]

It doesn't take 800 lb.ft of torque to move these new trucks, sorry if you don't understand how this power is made but it's pure fuel delivery. Less power equals less fuel. It won't tow 20k lbs as well but in a half ton that's not neccessary...

It isn't detuning that would make it get better mileage. Of course we detune our engines every time we don't push the loud pedal as far down, but the main things that hurt the engine's efficiency are retarded timing, EGR, and a DPF that is restrictive and must get regenerated with burning fuel every so often. These items have played an increasingly important role in reducing mileage numbers. The emission equipment is costing a lot of fuel by making the engine run inefficiently.

It's not simply having less available torque that gives better mileage. I added power to my Cummins with a Smarty and improved the mileage. By that I mean I improved the hand calculated mileage over many tanks of fuel, not just what the computer read out said. If I used that extra power it would get worse mileage, but under light loads the advanced timing helps it run more efficiently and get better mileage.

 

[Dmace]

It isn't detuning that would make it get better mileage. Of course we detune our engines every time we don't push the loud pedal as far down

Last I checked, these new diesels were making 100% of their available torque at just above idle (1500 rpms +/-). So even going light on the throttle is not helping fuel mileage.

I agree the emissions stuff is hurting as well but I gaurantee you these new diesels even with the emissions chokers would get better fuel mileage with half the power.

 

[Renze]

In america if you drive a volvo pulling a 6000 pound load you are asking to be sued for everything you have if you get in an accident!! How do your spindles not get sawed off pulling that kind of load, it must be 3-4000lbs overweight??

Nope. Got 2.5 ton gross trailer, 1960kg load rating. It actually has 1350kg rated axles. I worked in the trade, and we had customers driving USA pickup trucks with 11.000lbs loads on a tandem with 2x 1800kg (3980 pounds) axles, legally rated 7700 pound gross trailer weight. they didnt feel unsafe because the load was only 60% more than the weight of the tow vehicle.

If you look at a Mercedes Sprinter in Europe, we get them as 10 ton combined weight 5th wheel trailer tractors. in the USA the same engine, axle ratio and transmission gets only 6 ton or so... they just adapt the ratings to the expectations of the US users...

At horse riding events, most people pull their horse trailers with 1200-1800kg rated family cars, though a standard 2 horse trailer is rated at 2000kg max. Because its common practice, insurance companies cant sue for this. Unless you do like my neighbour, she pulled the 2 ton rated trailer (with one horse in it, so just 1200kg) with a 900kg weighing, 1.2 liter Opel Corsa a few km to the training in town...