Diesel truck with best MPG

[Wnc3]

i have checked my 5.9 cummins 07 model 3 times and it ranges between 19 and 21 mpg the thing i like is all that power a gas engine with that power wouldn't get 5 mile per gallon.

You got that right....I had my gas rigs of yesteryear, still have a K-30 with a 454 for nostalgic reasons. What a gas hog.
I understand the case made in earlier post: higher upfront cost,higher maintenance , blah, blah blah...
But distance between fill ups is huge to me.

2006 Ram 5.9 with all the Banks add ons.

And no I haven't check the mileage on paper, ignorance is bliss...

 

[ljohnson778]

So using your logic, you think a diesel engine making 800lb.ft torque would use the same exact fuel consumption as one making 400 lb.ft. as long as the two are not "mashing the pedal" ? Hilarious!
Don't forget those more powerful engines have larger turbos, injectors, intakes, fuel pumps, etc...

You're so wrong, it hurts... The higher HP/torque tunes tend to be the most fuel efficient... They Only burn more fuel when asking the engine to do more work. That is, get to speed faster, or haul more weight than a lower HP tune. Guaranteed, two identical trucks, one with high HP tune, one stock, the high HP tune will burn less fuel maintaining the same highway speed.

 

[rsewill]

You're so wrong, it hurts... The higher HP/torque tunes tend to be the most fuel efficient... They Only burn more fuel when asking the engine to do more work. That is, get to speed faster, or haul more weight than a lower HP tune. Guaranteed, two identical trucks, one with high HP tune, one stock, the high HP tune will burn less fuel maintaining the same highway speed.

In big trucks, the big engines (within reason) get better mileage when driven at the lowest RPM before torque drops off than small engines - when driven at highway speeds. In other words, at 55 MPH the big engine will get better mileage than the small engine, all other things being equal. I loved running a bigger engine (500 HP) at 1300 RPM in the high hole doing 55 MPH. I could always get better mileage than a 300 HP doing 55 MPH. One loafs along, the other works hard when grossing 80k pounds.

 

[Raspy]

So using your logic, you think a diesel engine making 800lb.ft torque would use the same exact fuel consumption as one making 400 lb.ft. as long as the two are not "mashing the pedal" ? Hilarious!
Don't forget those more powerful engines have larger turbos, injectors, intakes, fuel pumps, etc...

Fuel consumption is based on how much power the engine is actually producing, not how much it is capable of producing. Just because a diesel can produce 800 ft lbs doesn't mean it is. And cruising along at 55 on level ground it is probably only producing 60 ft lbs or so to maintain the speed. So it doesn't matter if the engine is capable of 400 or 800, the mileage is based on 60 until more is demanded.

The next factor is efficiency and that is not the same as maximum.

An efficient engine that has proper cam timing, injection timing, non diluted combustion air (no EGR) and an open exhaust will do very well compared to ones that don't. That's an efficient engine. Efficiency affects the mileage all the time regardless of the power being produced. A Cummins capable of 800 ft lbs at 1500 RPM, but only producing 60 ft lbs at 1500 RPM, will get very good mileage. And simply detuning it so that it can't produce 800 ft lbs has no affect on mileage in my example where we are only asking for 60 at 1500.

So simply detuning an engine for less maximum torque is not going to guarantee better mileage. Better efficiency will. Lower torque capability doesn't necessarily mean better efficiency. And the maximum an engine can produce isn't what is is actually producing. RPM doesn't equal torque. Of course 800 takes more fuel than 400, but that's not the point or the criteria for improving mileage.

Is this stuff really this hard?

 

[buickanddeere]

You got that right....I had my gas rigs of yesteryear, still have a K-30 with a 454 for nostalgic reasons. What a gas hog.
I understand the case made in earlier post: higher upfront cost,higher maintenance , blah, blah blah...
But distance between fill ups is huge to me.

2006 Ram 5.9 with all the Banks add ons.

And no I haven't check the mileage on paper, ignorance is bliss...

. How can you compare the mileage of a carbed 80's era 454 gasser to a 2006 diesel? Compare the 2006 diesel to a 2006 gasser. The 2006 gasser will produce 300-365 HP depending on the brand . Mileage will be in the mid to high teens. Gasoline costs less per gallon, gas engine trucks cost less and gas trucks cost less to service.The 70'S, 80's and early 90's are long gone and diesels no longer have an advantage. You can thank the EPA , CAFE and ULSD for that.

 

[ljohnson778]

. How can you compare the mileage of a carbed 80's era 454 gasser to a 2006 diesel? Compare the 2006 diesel to a 2006 gasser. The 2006 gasser will produce 300-365 HP depending on the brand . Mileage will be in the mid to high teens. Gasoline costs less per gallon, gas engine trucks cost less and gas trucks cost less to service.The 70'S, 80's and early 90's are long gone and diesels no longer have an advantage. You can thank the EPA , CAFE and ULSD for that.

Diesels no longer have an advantage?? Huh?

I bought my diesel to move very heavy things very easily... and it does. For me, decent fuel mileage was simply an added bonus. I didn't spend north of $50k on a truck to whine about a few extra dollars going into the tank. I bought it to work, and it sure will outwork any gasser.

That being said, I have a Ford with the new 6.7 diesel and getting 16.2 all day long... pretty happy with that. :thumbsup:

 

[Raspy]

. How can you compare the mileage of a carbed 80's era 454 gasser to a 2006 diesel? Compare the 2006 diesel to a 2006 gasser. The 2006 gasser will produce 300-365 HP depending on the brand . Mileage will be in the mid to high teens. Gasoline costs less per gallon, gas engine trucks cost less and gas trucks cost less to service.The 70'S, 80's and early 90's are long gone and diesels no longer have an advantage. You can thank the EPA , CAFE and ULSD for that.

The mileage numbers seem good on the window sticker of gas trucks, but once they go to work and actually have to produce some power, the mileage drops WAY off and they are revving way high to do the job. Get back to me after you've put 200,000 or 300,000 miles on a gasser under heavy conditions. Diesels have a big advantage because they are made to work hard and run at lower RPM. I'm perfectly willing to spend more up front to get the real workhorse power plant and the real world mileage. Mileage under load more than makes up for the fuel cost difference. But then, some folks just want the low entry price, or don't work their trucks and that's fine too.

My Cummins is a good example: It has 250,000 miles on it. I use it to tow my tractor and other things through the Sierras. It doesn't use a quart of oil between the 10,000 mile oil change intervals and never has. I reprogrammed it at 10,000 miles and it has run better than new ever since. I have never had to get a smog check like gassers do. There have been no problems of any kind with the engine. I'll probably run it to about 500,000 miles and am expecting it to do that with very little maintenance.

Try those stats with a gasser.

Even if the cost worked out to be the same between a diesel and a gasser, I'd ALWAYS pick the diesel. They're just better. That is, unless your criteria is a lower initial cost. Mine isn't.

 

[PoorMansCat]

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

its an expression... da

 

[Wnc3]

. How can you compare the mileage of a carbed 80's era 454 gasser to a 2006 diesel? Compare the 2006 diesel to a 2006 gasser. The 2006 gasser will produce 300-365 HP depending on the brand . Mileage will be in the mid to high teens. Gasoline costs less per gallon, gas engine trucks cost less and gas trucks cost less to service.The 70'S, 80's and early 90's are long gone and diesels no longer have an advantage. You can thank the EPA , CAFE and ULSD for that.

Points taken on the EPA ,Cafe, Usld.
The reliability of some late diesels, especially Navistar in Fords has been less than stellar.

That said, all the big blocks v10 Ford and Dodge and the GM 8.0 drink gas and basically suck (fuel)
The Ford 6.2 shows some real promise, but I'm not sure about mpg.

Anyway, I have considered buying a gas rig but I just can't stand the smell of gas and I can't hear the engine running.
And the power band is great at lower RPMs and the mpg is a nice bonus. Oh yeah, they pull really well....
To each his own. Keep on trucking!

 

[ljohnson778]

Points taken on the EPA ,Cafe, Usld.
The reliability of some late diesels, especially Navistar in Fords has been less than stellar.

That said, all the big blocks v10 Ford and Dodge and the GM 8.0 drink gas and basically suck (fuel)
The Ford 6.2 shows some real promise, but I'm not sure about mpg.

Anyway, I have considered buying a gas rig but I just can't stand the smell of gas and I can't hear the engine running.
And the power band is great at lower RPMs and the mpg is a nice bonus. Oh yeah, they pull really well....
To each his own. Keep on trucking!

Exactly... I knew the entry fee for going diesel, and it works for me...