Gas or Diesel

pnichols wrote:
I wonder what makes some think that diesels don't "gobble the fuel" when pulling loads up long hills with their turbos boosting away???

The energy has to come from somewhere .... most likely the fuel tank.

By the way, here's the engineering equation for where horsepower comes directly from. Notice that the equation does not care whether one is talking about a diesel or a gasser engine that's making the torque from power -> horsepower. But what it doesn't show is that a diesel pulls DIFFERENT, not BETTER than a gasser when both have equivalent horsepower. Preference is everything and Detroit has made sure (other than Ford with the good old V10) that the preference winds up being diesel because they (or maybe the EPA) refuse to make a pulling gas engine:

Torque = Horsepower X 5252 / Revolutions Per Minute

(For one exception example, see my earlier post above about a 1965 Ford I once owned that had a pulling gas engine.)

More than like because a diesel gets about 30 to 35% better fuel economy.

Or a gallon of diesel has about 13 to 15% more energy/ gallon than gasoline.

Or a diesel engine has virtually no pumping loses because it has no throttle plate.

So are you saying with your HP formula there is no difference between fuel burning rate with different fuels? If so, LOL.

Here is some news for you:

BTU's for diesel is right around 129,500/ gallon

BTU's for gasoline is right around 112,00/ gallon.

BTU's for methanol is right around 57,000/ gallon.

BTU's for nitromethane is right around 47,000/ gallon.

Now, do you really think you will get even close to the same fuel mileage if you use lets say methanol instead of gasoline?

Or do you think you will use around twice the amount of methanol than that of gasoline because gasoline has around twice the energy/gallon?

Like I said; with my 600 hp supercharged engine I burn about 1.25 gallons of gasoline / 1/4 mile. That is 5 gallons/ mile........not 5 miles/ gallon. :E

Good luck selling that to the public for a towing vehicle with those MPG figures. :B

What is interesting are the dyno specs from clapping two low PSI turbos on the venerable Ford V-10. It will need a new tune to understand that it isn't a NA motor anymore, but even a slight boost in pressure to compensate for altitude does wonders for this engine. The engine has a lot of cubic inches and low RPMs, so even a 5-7 PSI in boost would make the V-10 compare favorably to a diesel. It won't BE a diesel, but it will give them a run for their money, albeit at a higher RPM range.

IMHO, it is a matter of won't than can't here. Ford's EB proves that one can make a gasser with the torque/power curves similar to a diesel.

I wonder what makes some think that diesels don't "gobble the fuel" when pulling loads up long hills with their turbos boosting away???

The energy has to come from somewhere .... most likely the fuel tank.

By the way, here's the engineering equation showing where torque comes directly from. Notice that the equation does not care whether one is talking about a diesel or a gasser engine that's making the torque from horsepower. But what it doesn't show is that a diesel pulls DIFFERENT, not BETTER than a gasser when both have equivalent horsepower. Preference is everything and Detroit has made sure (other than Ford with the good old V10) that the preference winds up being diesel because they (or maybe the EPA) refuse to make a pulling gas engine anymore:

Torque = Horsepower X 5252 / Revolutions Per Minute

(For one exception example, see my earlier post above about a 1965 Ford I once owned that had a pulling gas engine.)

Turtle n Peeps wrote:

Sport45 wrote:
On the other hand, 15psi of boost would have a 6.8 liter engine acting like a 13.6 liter (830 cubic inch) NA. That'd certainly be fun... :)

And would gobble fuel like a drunken sailor. :R At around 475 HP my engine eats about 1 gallon/ 1/4 mile run at WOT.

But wasn't it fun? ;)

I never said it would be thrifty...

Why don't we settle it all by hooking up frame to frame V-10 vs powerstroke same body and cab each truck.we will put the powerstroke going up hill and the v-10 pointed down hill. Wait lets pop some popcorn this is gonna be a good show.
I do realize all the hot shots and big trucks use a gasser because it is cheaper and pulls just as well :)

Sport45 wrote:

pnichols wrote:
Now ... if Ford would offer a turbo charged V10 ... then we'd begin to see the switch from diesels by the towing crowd back to smooth running cheap to maintain easy to find gas for gasser engines. The V10 gasser is already engineered to have a broad relatively flat torque curve for truck use. All it needs to complete the picture is a turbo for mountain use.

So true. And it wouldn't really need "boost", just enough turbo to maintain sea level manifold pressure at elevation.

On the other hand, 15psi of boost would have a 6.8 liter engine acting like a 13.6 liter (830 cubic inch) NA. That'd certainly be fun... :)

And would gobble fuel like a drunken sailor. :R At around 475 HP my engine eats about 1 gallon/ 1/4 mile run at WOT.

pnichols wrote:
Now ... if Ford would offer a turbo charged V10 ... then we'd begin to see the switch from diesels by the towing crowd back to smooth running cheap to maintain easy to find gas for gasser engines. The V10 gasser is already engineered to have a broad relatively flat torque curve for truck use. All it needs to complete the picture is a turbo for mountain use.

So true. And it wouldn't really need "boost", just enough turbo to maintain sea level manifold pressure at elevation.

On the other hand, 15psi of boost would have a 6.8 liter engine acting like a 13.6 liter (830 cubic inch) NA. That'd certainly be fun... :)

Vulcaneer wrote:
Having previously owned a 2006 V10 6.8 30V F350, I know where you're coming from. But I cannot agree with your preference. Spent too much time at 4000 RPMs pulling long hills in 3rd, or even second gear. Try pulling 13,000 pounds up over Donner pass sometime. You won't be able to hear your radio. Or much of anything else after you get over the top. Been there, done that, got the T shirt and the hat. My diesel does it so much better.

Well .... our ton-and-a-half E450 V10 with a 4:56 differential pulls our 11,800 lb. motorhome and our boat just fine over Donner ... not getting passed by diesels, either. I don't mind 4000 RPM if I know the engine is desinged for it and we don't care to listen to the radio when traveling. The V10 makes no noise when cruising along at 2100 RPM. What I do not care for is the thumping/grunting tailpipe sounds and tappet-dancing underhood sounds of a diesel on the highway or late at night in a campground. FWIW, I can also idle my V10 for hours in a campground or out in the middle of nowhere without needing to set a high-idle knob - for emergency battery charging, emergency motorhome A/C, and emergency motorhome heating - with nary a sound outside or inside and with no vibration in the floors ... smooth as silk.

As for ultra low end power (crankshaft torque) from a gasser: My 1965 Ford 3/4 ton heavy duty pickup (15 leaf springs in each rear stack and 3 gas tanks) with it's long-throw-crank 390 V8 had and needed only 4 gears. The first gear was what they called in the old days a Granny Gear, so it could climb a mountain idling. The engine probably wouldn't spin faster than 2500 RPM on a good day going downhill. We have a 500 foot long driveway with a very steep first 150 feet - probably a 15% grade or more - and that good old Ford gasser would pull it in 3rd gear. So I'm convinced ... the old Detroit crowd could build a gasser that acted like a diesel if they wanted to ... probably the EPA is preventing it nowadays.

Sport45 wrote:
I think most diesel owners are more in love with the turbocharger than the fuel. They just don't realize it.

You hit the proverbial nail on it's proverbial head with that keen observation. I've stated in post after post that it's blatantly not right to compare TC diesels to non-TC gassers. The problem is ... there's no TC gasser truck engines available to speak of that are worth their salt. It probably isn't going to happen either - the opposite is happening - vehicle manufacturers are close to fully Europeanizing the U.S. market by inundating us with little tiny turbo charged diesels in everything. Lawn mowers and Harley motorcycles are next after the conversion to diesel delivery trucks, diesel small motorhomes, and diesel socker-mom-mobiles is complete.

My brother said a very honest thing about his older 4X4 NA diesel pickup - his words about the truck were something akin to "gutless wonder".

Now ... if Ford would offer a turbo charged V10 ... then we'd begin to see the switch from diesels by the towing crowd back to smooth running cheap to maintain easy to find gas for gasser engines. The V10 gasser is already engineered to have a broad relatively flat torque curve for truck use. All it needs to complete the picture is a turbo for mountain use.

I think most diesel owners are more in love with the turbocharger than the fuel. They just don't realize it.

A NA diesel is a wheezing pig on mountain passes, same as gas. My late father in law pulled his TT with a 6.2l diesel Suburban and I can tell you from experience it was no powerhouse. The gas engines of the day would easily outrun it. They couldn't touch it for fuel mileage though. And diesel was much cheaper than gas back in the day.