Diesel vs gas......................

[blt2ski]

OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diesel, pro and con, I will either leave your thread, or copy and paste pertinant info to the 4 posts of pro and con of diesel or gas. This can include the GM 8.1 vs Dmax or Ford V-8/10 vs PSD etc too.

Be real and honest in you answers, not hear say, flaming etc PLEASE!

If posts are good ones, I will leave, if inflamatory or trolling in nature, they will be deleted! I will get this stick'd to the top for future parusing for those that need this type of info.

Added 6-23-04

We are getting closer to answers I am looking for etc.

Stuff like Ken's - T-Bone posts are good. There are a few others of you that have not posted, some with a 9 point question and answer type to figure out how you went with one or the other. If you are one of those, PLEASE repost in this thread. I may have to look up whom has done this and PM you, but if you think this is you, you now know what to do.

Also, for those of you with $ per gallon for either fuel right now, I would prefer to see a post with ...."in my area, diesel is typically .10 less than unleaded" then explain your numbers. As currently in the Seattle area, diesel and unleaded are any where from 2.05 -2.30 per gallon, with mid test .10 more and premium about .20 more, with equal high low splits. Two weeks ago those prices were upwards of .30 -.40 per gallon more. people were posting $ per gallon that were for me. "I wish" If someone is reading your post a year from now, they may want to know where your paying 1.65, when the price of fuel is over $3 per gallon. Let's keep prices out of it if possible.

Bert and tin tipi, got into a good discusion on the pros and cons of RPM's, drive train etc. I would prefer to NOT see the quote of the other in responding threads, maybe just write a quick wording of re tranny gearing, instead of the whole 40 words or so in that paragragh, so the repsonse is shorter if possible quicker and easier to read etc.

I have deleted some 15+/- posts, that were off topic etc. Please note, I am trying to keep this at the top, as the ONLY gas/diesel thread in this area. So if one is trying to decide, we do not have to go thru this BS any more. As such, I will be deleting ANY future posts close to resembling this type of topic. I may have to change "this" title to a better one, if one has a better sounding title, to be more positive, better claification, let me know here, or in a PM/e-mail, what ever you feel most comfortible with.

Again thank you for all of you that are keeping responses positive, etc.

Also we could use a few more positive reasons to go gas, as many can see I have both gas and diesel, both have a place! Both have positive reasons to buy that fuel, lets keep the threads etc to that purpose only!

Marty

[Highbeam]

Great story David. I think you hit the nail on the head. I get nervous when I hit 4200 rpm in second gear doing 55 mph in my gasser.

I especially like the quote from the kids in the back, sure sounds nice.

[Camper_G]

Good story if you care about maintaining 60mph up a steep grade, I for one do not, but each his or her own. I think it's a given that a diesel will out pull a gas engine of similar displacement no argument on that here.

[DavidPhillips]

Here is a comparison of two identical rigs except one has a 300 hp rated gas engine and the other has a 300 hp rated diesel engine.

The gear ratios will be different on the gas truck to allow comparable tow ratings.

Tires
245-75-16

Gears
Gas: 4.10
Diesel: 3.73


Now the gas guy is tooling along in OD cruise control set at 60 mph pulling his 5er at 2035 rpm and life is great. The diesel guy is following along behind at 1850 rpm.


They are approaching a hill that is going to require 360 lb. ft. of torque applied to the crankshaft to go 60 mph toward the steeper part of the hill with the load they both have.

Gasser guy is beginning to look a little nervous as the transmission shifts to
3rd and rpms go up to over 2700. As the hill begins to get steeper gasser guys transmission downshifts to second and rpms jump to over 4200 but he is confident that he will hold her at 60 mph which he does.

As he goes around the curve he sees that the hill gets a little steeper. The hill ahead will require a force on the crankshaft of 500 lb. ft. to keep the crank turning with the load he has traveling at 60 mph and 350 lb. ft. to go 50 mph.


Gasser guy gets to the steepest part of the hill and is really beginning to break a sweat as the speedometer starts to drop but he's got her wide open and is able to keep the massive load traveling at 50 mph which seems like he's hauling tail to be climbing such a steep grade. His confidence is regained when the speedometer steadies up around 50 mph.


He looks over in the other lane to see Diesel guy passing by waving.

Diesel guy waves at gasser guy as he passes and glances at his gauges.

He's in OD running 1850 rpm.



Gasser guy hears the kids in the back talking one of them says, "Wow that truck sure does sound good".



2006 Silverado

Gas Engine

300 hp @ 4400 rpm
360 lb. ft. @ 4000 rpm

Diesel Engine

300 hp @ 3000 rpm
520 lb. ft. @ 1600 rpm




I love the smell of diesel in the morning.

[DavidPhillips]

Sport45 wrote:
A diesel pulling a load at speed does the same work as a gas engine pulling the same load at the same speed. Engine rpm has nothing to do with the "work" done. This logic would indicate you could replace your gears with a 2.75:1 set, slow your diesel down, do less work and last even longer.

It does the same work. Meaning like pulling a 5er at 60 mph. Turning less rpm means less wear and less fuel used. Rpm means everyhing since the mass being moved is equal. What other difference is there?

Diesel has more Btu's per gallon, but the real effeciency killer in the gasoline engine is the throttle plate. Engines are air pumps and having to draw vacuum against the throttle to control power saps energy.

Gas engines mix air and fuel and ignite it in the cylinder. Diesel is simply injected into the compressed air which is more effecient. The end result of explosive force pushing the piston down is the same. Only the diesel has more power produced for the amount of fuel used. More BTU's per gallon and more foot pounds of torque per BTU.

Air is allowed to enter a normally asperated engine by the intake valve opening. Sort of like an empty glass is not empty. It has air in it. Engines do not suck in air. A gasser has a restrictive intake by virtue of controlling the air fuel mixture.

vacuum is a reference for a lack of force, that force being atmospheric pressure @ 15psi.
15psi Baro = 0"Hg vacuum
0psi Baro = 30"Hg vacuum
Intake valve open, piston @ TDC - piston has 'displaced' cylinder volume, no air flow.
Piston drops, Barometric pressure pushesair in to fill the increasing cylinder volume.

Solid proof? If you're driving an 18-wheeler I guess this is a good comparison. Otherwise it's just ancedotal information. The space shuttle runs on liquid hydrogen, that doesn't make it a good fuel for your typical 737. Look at all the freight pulled by diesel-electric trains. Should we all go diesel-electric? That's probably the best use of a diesel engine I know of. The engine is designed and operates at a set rpm. The rpm never changes, only the load.

90% or more of the vehicles on the road now are transverse engine front wheel drive. Is this solid proof that it would be the best drive system for a pickup?


Diesels have their place. They are a very good fit for over-the-road tractors, large boats, construction machinery, and the military. In 1/2 to 1-ton pickups it's a very grey area. Everyone has their own criteria and sometimes gasoline power is the best fit.

If you have the money to buy and own a diesel because it sounds cool, go for it!

There are a lot more diesel engines rolling down the road than you think.

I was refering to rubber tired towing or load bearing vehicles. Being that we all tow RV's or drive big heavy motorhomes it is the same thing as a semi truck.

If you really want some more proof that diesel is better for doing work look at fuel oil powered vessels like tug boats, crew boats, ships.

Heavy work being done by generators, drilling rigs, compressors. The list goes on and on.

We are comparing Diesel to gas not trains to cars.

So if there were gas powered ships we could use that. Iguess they went out of business with the gas powered semis.



Gas is great for weedeaters and stuff.

[Rvndave]

Even with the higher fuel prices of diesel I will save the cost of the diesel in fuel savings. There is not a big block gas engine in a comparable truck that will achieve the fuel mileage I get with my diesel. As a bonus I get much more power than any of the gas engines available. Like the old saying goes you can pay a little more now, or much more later. After I recoup the cost of the diesel in fuel savings I will gladly accept the higher resale value a diesel offers.

[JIMNLIN]

Sport45 wrote:
Diesels have their place. They are a very good fit for over-the-road tractors, large boats, construction machinery, and the military. In 1/2 to 1-ton pickups it's a very grey area. Everyone has their own criteria and sometimes gasoline power is the best fit.

If you have the money to buy and own a diesel because it sounds cool, go for it!

check with the folks down at the truck stops that are on the road every day making a living [commercial/hotshoters] with the same 2500/3500 diesel powered trucks we pull our RVs with. Folks, like myself, that have 100-150+ mile a day work commute that drive their trucks to work gettin' 20+ mpgs. We can't afford a BB gas or V-10 fuel consumption. As you say everyone has their criteria for what they drive. Mine, as many that live out here, find the diesel offers the best way to lower fuel costs. Gas works for some but not everyone.
JIM

[Sport45]

DavidPhillips wrote:
More torque at lower rpm means easier towing and the engine is not working as hard and will last much longer.

A diesel pulling a load at speed does the same work as a gas engine pulling the same load at the same speed. Engine rpm has nothing to do with the "work" done. This logic would indicate you could replace your gears with a 2.75:1 set, slow your diesel down, do less work and last even longer.

Fuel usage is relative to power here. More BTU's in diesel. Plain and simple.

Diesel has more Btu's per gallon, but the real effeciency killer in the gasoline engine is the throttle plate. Engines are air pumps and having to draw vacuum against the throttle to control power saps energy.

Need some solid proof?

Look at the vehicles on the road. Trucks that are hauling are all diesel.
You do not see any gas powered semi trucks. These companies are in the business to haul for money and use what makes money.

Solid proof? If you're driving an 18-wheeler I guess this is a good comparison. Otherwise it's just ancedotal information. The space shuttle runs on liquid hydrogen, that doesn't make it a good fuel for your typical 737. Look at all the freight pulled by diesel-electric trains. Should we all go diesel-electric? That's probably the best use of a diesel engine I know of. The engine is designed and operates at a set rpm. The rpm never changes, only the load.

90% or more of the vehicles on the road now are transverse engine front wheel drive. Is this solid proof that it would be the best drive system for a pickup?


Diesels have their place. They are a very good fit for over-the-road tractors, large boats, construction machinery, and the military. In 1/2 to 1-ton pickups it's a very grey area. Everyone has their own criteria and sometimes gasoline power is the best fit.

If you have the money to buy and own a diesel because it sounds cool, go for it!

[DavidPhillips]

Diesels sound cool.


The fuel filters are not very expensive at all on my truck. $15.00
I can change it in less than five minutes without any tools.
You just don't change them that often. 30,000 miles or so.
Most people who are fuel filter maniacs change them when they are still perfectly good.

A gasser could probably use a filter at that interval as well.

Fuel additive is needed on a diesel to provide trouble free fuel. It actually pays for itself in mpg gained. No difference in cost of operation.


It holds 7 qts of oil. Oil for a diesel is no more expensive than oil for a gasser. The oil change places charge you for extra oil, diesel or gasser, that's it. Change interval is actually the same as a gasser. You can go longer if you want using oil sampling.

Oil filter is the same thing as a gasser, just spin it off and put on a new one.
Can't see where the big difference is there.


Basic cost of operation comes down to fuel price.

Diesel is sometimes higher than gas sometimes lower. MPG is without a doubt going to win over in the long haul.

Get low 20's empty, 13-15 towing.


Now the big issue.

Power and longevity. They are related.

The power in the gasser is way up there in the rpm range whereas this is not so on a diesel.

More torque at lower rpm means easier towing and the engine is not working as hard and will last much longer.

Fuel usage is relative to power here. More BTU's in diesel. Plain and simple.

Need some solid proof?

Look at the vehicles on the road. Trucks that are hauling are all diesel.
You do not see any gas powered semi trucks. These companies are in the business to haul for money and use what makes money.

All of the gasser semi truck companies must have already went out of business.


Diesels sound cool.

[D_Bach]

Steak2k1 wrote:
Well: All I can say is that a couple of guys have told me they get close to 30 mpg...on a CTD. speed used..?? I do not know. All heresay of course. I do not own one but am seriously looking at it.

I would love to hear and read of some actual mileage (non-towing) with the Cummins diesel and for that matter the Power Stroke and the Duramax..

ANYONE..??

I have a '06 Chevy 2500, Duramax Diesel, Crew Cab, short bed, 4 X 4, 6 Speed Allison Xmission.

Empty:
70 to 75 mph Highway - 16 to 18 mpg.
Around town - 14 to 15 mpg.

Towing:
24 foot Zinger TT (3400 lbs empty) - 12 mpg.

The truck has 20K on it. I hear the mileage will get a little better with time. All in all, I love it. The truck runs like a scalded dog and pulls great.

Oil changes aren't that bad, the cost is about $80.00, this is with the synthetic oil (Shell Rotella). I change the oil every 6K or so, I changed the oil in my gasser at 3K. The oil change issue is a wash, nothing to worry about.

Clean Diesel?
Also not a problem. From what I read it's been slowly introduced since last June. We are more than likely already running on it.

[cicamper]

Steak2k1 wrote:
Well: All I can say is that a couple of guys have told me they get close to 30 mpg...on a CTD. speed used..?? I do not know. All heresay of course. I do not own one but am seriously looking at it.

I would love to hear and read of some actual mileage (non-towing) with the Cummins diesel and for that matter the Power Stroke and the Duramax..

ANYONE..??

Steak2k1-
On the highway at 75 mph, I get between 19-20 mpg empty. Have not yet driven full tank with 6k lb trailer. This is with the 6.6l Duramax/Allison setup.

[hone_eagle]

I get 18 - 20 empty non city,50 mile per hour or less, few stops on county roads.imperial gallons.Note the location of poster if in Canada they may be using bigger gallons, but not I think 30 mpg big 🙂

[Steakman]

Well: All I can say is that a couple of guys have told me they get close to 30 mpg...on a CTD. speed used..?? I do not know. All heresay of course. I do not own one but am seriously looking at it.

I would love to hear and read of some actual mileage (non-towing) with the Cummins diesel and for that matter the Power Stroke and the Duramax..

ANYONE..??

[Rvndave]

You need to shop around for your filters. I get fleetguard filters from Geno's Garage. The 30,000 mile filter pack is under $100. Four oil, two fuel, and one air filter is included. Web address listed below
http://www.genosgarage.com/prodinfo.asp?number=MK2003-AF-FL-DG

[kudos383]

No the iol filter they say is about 42$ the rest of the bill i assume is for their time.I went to another dealer here in town and he wanted 94$to change oil.so i guess in Ohio and WV they stick it to you.I would of kept the ford had they not been slamming me.the next 80$ oil change was to also have the 93 dollar fuel filter change,plus the 20$to rotate the tires.

[cableguy574]

My Ford dealer changes the oil for 39.39 with the coupon, which they email out for diesel owners. :B