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

[willald]

You still have not answered the question. If the big block has more horsepower, why is it not rated to tow more than the diesel?....Since you feel that horsepower is the "only" way to measure engine power, I find it interesting that you can't explain why the lower HP, yet higher torque diesel has the superior tow rating.

I'll answer that, or at least try to.

As we all know, many, many, MANY factors go into tow ratings (I'm strictly talking about GCWR, not GVWR). GCWR rating is based mostly on how much weight the drivetrain can handle. How much weight a drivetrain can handle, is determined by several factors, not the least of which is - LONGEVITY OF SERVICE (how long can a drivetrain generate a given amount of power before wearing out).

It IS true (no matter what diesel disciples will try to say), that the more horsepower you can generate, the faster/better you can move a load. As has been said many times, you can generate horsepower two ways - high torque at low rpm, or low torque at high rpm. Both ways, generate the same horsepower. However, typically, the former of those (high torque at low rpm) is more efficient, and likely to last longer in reciprocating (piston) engines.

As I said, many factors about the drivetrain are considered, for GCWR rating. Longevity of service is one of those factors, and is why the diesel has the higher GCWR rating. It (diesel) can handle the higher load, without wearing out as fast. Yes, the gasser can generate more horepower, and could handle more GCWR load than the diesel, since it has more horsepower. But, the gasser would NOT LAST AS LONG as the diesel, since the gasser would have to turn 5,000 RPMs all day in order to do it.

Still, it is quite possible to build the gasser V8 so it COULD turn that fast all day, and still last as long as the diesel. Would use up obscene amounts of fuel, but it could be done. If it was built that way, the gasser WOULD indeed have a higher GCWR rating than the diesel, since it has more horsepower.

But, as many have said, it gets into economics - a big block V8 gasser that could turn 5,000 RPMs all day long and still last 200,000 miles, would be a VERY expensive engine to build, and would cost too much to put in regular production trucks. Much cheaper to just give the gasser a lower GCWR rating and gear it to not turn so many RPMs. Then, offer a diesel engine with a higher GCWR rating, since even though it has less maximum horsepower, it can still generate enough horsepower to move the bigger load, and do it without twisting as hard.

Anyway, hope that answers the question, bluenote.

Will

[bluenote]

Why do I have to explain tow rating and torque when my post was related to horsepower. The kid said the diesels have more power. If we measured power in lb/ft, the diesel would be superior. But we don't, me measure it in horsepower and regardless of the tow ratings, the 8.1 vortec has more horsepower than any diesel currently offered in a pickup.

And...if you read the post accurately, you'd see I agreed with the statement that the big block has more horsepower. However, your statement seem to imply that the superior horsepower made the big block better somehow. You still have not answered the question. If the big block has more horsepower, why is it not rated to tow more than the diesel? Case in point...a Chevy 3500 dually with the LLY Duramax and Allison is rated for 1,500 more GCVWR than the equivalent truck with a vortec 8100 (actually, the big block has to have 4.10 rear gears to get even that close in ratings). Since you feel that horsepower is the "only" way to measure engine power, I find it interesting that you can't explain why the lower HP, yet higher torque diesel has the superior tow rating.

[Ag_Teacher]

As far as the Italian with no Face (must have lost it shaving), engine power is measured in a term called Horsepower. The 8.1 G.M. engine has more horsepower than any diesel engine offered in a pickup.

You are correct in saying that the vortec 8100 has more horsepower in stock form than any of the 3 diesels available in the US light duty truck market. Now, please explain why that engine is rated to tow less than the (by your standards of engine power) lower powered diesel engines? The reason, of course, is that horsepower is only one measurement of engine power. It is also a measurement that is derived from a formula applied to another form of engine power measurement called torque....AND....Regardless what you say, think, or feel about horsepower versus torque, the diesels have more available torque. It must be that the torque output of these engines has just a tiny bit to do with the irrefutable fact that they are rated to tow more, with all other things being equal.

Why do I have to explain tow rating and torque when my post was related to horsepower. The kid said the diesels have more power. If we measured power in lb/ft, the diesel would be superior. But we don't, me measure it in horsepower and regardless of the tow ratings, the 8.1 vortec has more horsepower than any diesel currently offered in a pickup.

[59022]

Absolutely not. Diesels burn less fuel than gassers for a given job, so they are more economical. And that is why diesels are so prevalent in the heavy equipment.Bert

Diesel engines convert their power to run electric motors on heavy mining equipment, like the kind you find at strip coal mines, just as diesel/electric locomotives operate. I suppose you could use a V-16 gas engine, but you'll need an extra tank car for the fuel required.

With diesel topping $2/gal and $3.50/gal in Canada, the chances of gasoline following suit next Spring are pretty good. The current reasoning is because of the switchover to heating oil. If the NorthEastern USA has a mild winter, the terminals will be filled with excess diesel and the prices will drop. If, however, it's a nasty mix and with lots of cold weather, the prices will remain high.
Everytime a refinery is taken out of service for maintenance, you'll see a rise in prices the next day.

It's been diesels for us, practically forever. We farm and run a trucking operation simutaneously. We use 2000 gals of red every three months (farm diesel) and pay the same pump prices for the OTR's as you do. With engines lasting nearly forever these days, it's hard to go back to gassers. Nearly every truck engine has more than 550,000 miles on them. Of the four farm generators, only one has been rebuilt at 22,000 hrs. A gas engine wouldn't survive that long.

Slowing down this past Summer has helped increase mileage. We have a 75 mph limit/70 for trucks here and by slowing down to 65/60 has helped conserve = 8mpg.

[BertP]

Sure, it will burn more fuel, probably break more often, and not last as long..but hey a gas engine COULD be manufactured that would keep up with the diesel. Just kidding a bit Bert. Face it, if there was a realistic way that a gas engine could be developed that made some type of sense for heavy equipment or heavy hauling, we'd have it. Some heavy equipment/trucks costs hundreds of thousands or even millions of dollars, and they all have some form of diesel engine in them. Almost anything is possible, it just doesn't always make sense.

And that has been my point all along. Gas engines can do anything that diesels can. But, since they burn more fuel doing it, it generally does not make sense to do that. Also, since diesels burn less fuel and are, therefore, more economical to run, far more development work has gone into building medium and heavy duty diesels than gassers. After all, if they can both do the job, why use the one that burns more fuel and increases your operating costs? Economics.

I've owned quite a few aircraft, all powered by gas engines. Certainly for light weight in a piston powered aircraft it only makes the most sense. A six cylinder Cat in a two place aircraft makes as much sense as a 8.1 in a D8.

This is an interesting comparison. In the case of the diesel vs gasser, the economics play in favor of the diesel and that's the way that the industry has gone. However, in the case of aircraft engines, you will be had pressed to find a new piston engine developing more than around 500 HP. Why? Because the turbine has taken over in that market. Yet, contrary to the diesel vs gasser scenario, the turbine consumes more fuel than the gas equivalent. So, why has the turbine taken over? Simply priorities. As you pointed out, weight is an extremely important factor in aircraft engines. A turbine weighs a fraction of a similarly powered piston engine, so it has a major advantage. Also, the durability of the turbine far outstrip that of any piston engine. So, in spite of the fact that the turbine burns more fuel than a piston engine, the overall economics of the turbine win, just like the diesels do in trucks.

Our smallest piece of equipment is an ASV RC50, it has a 50hp Cat diesel in it. It is a wonderful piece of machinery for it's inteded purposes. The older, similarly sized pieces of equipment that were gas powered are considered antiques and are almost impossible to sell. Same with some types of boats, if they don't have a diesel or two they just aren't considered as desireable, largely due to safety considerations.

Diesels can be excellent engines and I have never knocked them. I was just trying to address the falicy that gassers are incapable of doing any heavy work. They have for years and, if technological developments decrease fuel consuption of them to the levels of diesels, we may see them again.

People that make a living with machinery demand the best tools for the job. For years now that has overwhelmingly been accomplished with diesel powerplants. It's not due to slick marketing or misinformed consumers. Why would someone want to burn more fuel and be less safe for goodness sake?

Absolutely not. Diesels burn less fuel than gassers for a given job, so they are more economical. And that is why diesels are so prevalent in the heavy equipment.

Bert

[justJeff]

Sure, it will burn more fuel, probably break more often, and not last as long..but hey a gas engine COULD be manufactured that would keep up with the diesel. Just kidding a bit Bert. Face it, if there was a realistic way that a gas engine could be developed that made some type of sense for heavy equipment or heavy hauling, we'd have it. Some heavy equipment/trucks costs hundreds of thousands or even millions of dollars, and they all have some form of diesel engine in them. Almost anything is possible, it just doesn't always make sense.

I've owned quite a few aircraft, all powered by gas engines. Certainly for light weight in a piston powered aircraft it only makes the most sense. A six cylinder Cat in a two place aircraft makes as much sense as a 8.1 in a D8.

Our smallest piece of equipment is an ASV RC50, it has a 50hp Cat diesel in it. It is a wonderful piece of machinery for it's inteded purposes. The older, similarly sized pieces of equipment that were gas powered are considered antiques and are almost impossible to sell. Same with some types of boats, if they don't have a diesel or two they just aren't considered as desireable, largely due to safety considerations.

People that make a living with machinery demand the best tools for the job. For years now that has overwhelmingly been accomplished with diesel powerplants. It's not due to slick marketing or misinformed consumers. Why would someone want to burn more fuel and be less safe for goodness sake?

[BertP]

Bert, sometimes I swear you argue just to re-read your arguments...

Then you should try rereading what I posted.

Say what you want about the GCVWR and GVWR of the different configurations, the fact remains....ALL current GM trucks with the Duramax/Allison have the exact same drivetrain, and the same frames, brakes, rear gears and axles for that matter. Therefore, the 1,500 pound higher GCVWR of the dually must be related to something besides the drivetrain capacities. The dually has a higher payload capacity, and therefore, is more likely to be able to max out the GCVWR. I don't believe that's just a coincidence...it's very likely that's the reason the dually has a 23,500 pound GCVWR.

Again, the fact that the same DRW truck with a DMax but the manual tranny has a 22K GCVW instead of the 23.5K you refer to implies that there is more to it than the GVW rating of the truck. Whether you have the Allison or the manual tranny, the GVW is the same, but the GCVW is different.

Bert

[xmack]

Simply put diesel good, gas bad

[bluenote]

Bert, sometimes I swear you argue just to re-read your arguments...

Say what you want about the GCVWR and GVWR of the different configurations, the fact remains....ALL current GM trucks with the Duramax/Allison have the exact same drivetrain, and the same frames, brakes, rear gears and axles for that matter. Therefore, the 1,500 pound higher GCVWR of the dually must be related to something besides the drivetrain capacities. The dually has a higher payload capacity, and therefore, is more likely to be able to max out the GCVWR. I don't believe that's just a coincidence...it's very likely that's the reason the dually has a 23,500 pound GCVWR.

[BertP]

This part of your argument is flawed.

It does not matter which truck/cab configuration you get the Duramax in, all current DMax's are the LLY with 310HP and 605TQ. In addition, all current trucks with the Duramax have the same 3.73 rear gears and all of them with automatic transmissions have an Allison. Therefore, the Duramax will develop that same higher HP at the lower RPMs than the vortec 8100 in all 2500HD and 3500 configurations. The 2500HD and 3500srw trucks both have the same 22K GCVWR that has been available since 2001 with Duramax/Allison and 8.lL/Allison trucks (only when the big block is paired with the 4.10 rear gears). Since it would be nearly impossible to max out the GCVWR on 2500HD and 3500srw trucks without exceeding payload capacity through 5er or gooseneck pin weight, it does not make sense to up the GCVWR's of those trucks with the newest version of the Duramax.

I agree with the first part, but not necessarily the second. Since these trucks are used not only to pull RV's, but also commercial trailers (with a pintle hitch, for example), it would not be unreasonable to assume that the GCVW can be exceeded before the GVW of he truck is exceeded. You may run into difficulties with the max tounge weight, but the GVW sould be fine.

With the 3500drw however, it is more likely that one could get to the GCVWR, while still remaining under payload capacity. Therefore, those trucks are rated for 23,500 pounds of GCVWR with the diesel. So, you have a diesel engine with a 3.73 rear end that is rated for 1,500 pounds more towing capacity than a big block with a 4.10 rear end.

Unless you get the DMax with a manual tranny. In that case, the truck will have the same 22K GCVW as the 8.1.

I agree that torque is a different type of measurement than HP, but when you are considering the application of torque and HP in the case of light duty trucks when towing, the low end torque advantages of the diesel overcome the high end HP advantages of the big block.

Yes, there are advantages. I now have a DMax because of some of them. However, geared correctly the 8.1 will still outpull a DMax because of its higher HP. That may require a 4.56 RE - and the higher rpm that goes along with it - but it can get more torque and HP to the ground than the DMax because of its higher HP with the caveat that it has the proper gearing.

I was merely pointing out that with

ALL OTHER THINGS BEING EQUAL

the higher torque diesels have an advantage when towing, even though they have less horsepower.

And that is where we generally run into trouble. If everything else is equal (especially the gears), then the DMax will have an advantage over the 8.1, no question. If you look at the power curves for both engines, the 8.1 is developing around 250 HP at 3000 rpm (IIRC) while the DMax is developing 310 at the same rpm. That's quite a difference. So, from a dead stop until the 8.1 gets up to around 4000 rpm (or whatever rpm the 8.1 crosses the 310 HP mark), the DMax is developing more power than the 8.1. Any way you dice it, the DMax will walk away from the 8.1 up to that point. Now you may say that it doesn't take the 8.1 long to get up to 4000 rpm. But, if it is pulling a large load, that could take quite a while (relatively speaking).

Bert

[bluenote]

With the exception of the 3500 DRW (and then only with the allison), the 8.1 is rated the same as the DMax. Part of the reason, I believe, that the DMax is rated higher in that one case is because it develops more HP than the 8.1 at low rpm.

This part of your argument is flawed.

It does not matter which truck/cab configuration you get the Duramax in, all current DMax's are the LLY with 310HP and 605TQ. In addition, all current trucks with the Duramax have the same 3.73 rear gears and all of them with automatic transmissions have an Allison. Therefore, the Duramax will develop that same higher HP at the lower RPMs than the vortec 8100 in all 2500HD and 3500 configurations. The 2500HD and 3500srw trucks both have the same 22K GCVWR that has been available since 2001 with Duramax/Allison and 8.lL/Allison trucks (only when the big block is paired with the 4.10 rear gears). Since it would be nearly impossible to max out the GCVWR on 2500HD and 3500srw trucks without exceeding payload capacity through 5er or gooseneck pin weight, it does not make sense to up the GCVWR's of those trucks with the newest version of the Duramax. With the 3500drw however, it is more likely that one could get to the GCVWR, while still remaining under payload capacity. Therefore, those trucks are rated for 23,500 pounds of GCVWR with the diesel. So, you have a diesel engine with a 3.73 rear end that is rated for 1,500 pounds more towing capacity than a big block with a 4.10 rear end.

I agree that torque is a different type of measurement than HP, but when you are considering the application of torque and HP in the case of light duty trucks when towing, the low end torque advantages of the diesel overcome the high end HP advantages of the big block.

I was merely pointing out that with

ALL OTHER THINGS BEING EQUAL

the higher torque diesels have an advantage when towing, even though they have less horsepower.

[BertP]

Jeff - No, I am not 105 :).

I agree that the overwhelming choice of engine for heavy duty work is the diesel. My point has been that a claim that a gas engine cannot do the same amount of work as a diesel is incorrect. Yes, it will rev higher and burn more fuel than a diesel, but it will work the same. In spite of what seems intuitive, 500 HP at 1000 rpm is exactly the same as 500 HP at 5000 rpm or 10,000 rpm or .... you get the point. 500 HP is 500 HP regardless of what rpm it is generated at. Certainly, you will have to change the gearing to accomodate the different rpm, but as long as the engine is permitted to produce the 500 HP, you will get the same results.

Chris - I agree with most of your point, but HP is the only measurement of engine power. Torque is not power. HP can be derived from torque if we know the rpm, but torque itself is not power. It is true that, for a given set of tranny and RE ratios, a higher torque engine will get a larger load moving than a lower torque engine of the same HP, but that is because the higher torque engine can develop more HP at low rpm than the lower torque engine to get the load moving. With the exception of the 3500 DRW (and then only with the allison), the 8.1 is rated the same as the DMax. Part of the reason, I believe, that the DMax is rated higher in that one case is because it develops more HP than the 8.1 at low rpm.

Bert

[bluenote]

My German friend tells me no one drives a diesel car on the Autobon freeway,the can't keep up.
(Just my two cents)

That's very interesting. We hosted a foreign exhange student from Germany 3 years ago. His father owned a taxi firm, and most of their taxi's were diesel powered Mercedes Benz. He never mentioned any problem with driving them on the autobahn and I know for a fact that they used them out there regularly. In fact, he said that they can move right along with the fast traffic, pulling over only for the sports cars that are really hauling. Maybe a little VW diesel would run into problems, but there's no reason that any engine, regardless of engine type, couldn't maintain autobahn-type speeds when equipped with the proper gearing.

[wkdelsol]

My German friend tells me no one drives a diesel car on the Autobon freeway,the can't keep up.
(Just my two cents)

[bluenote]

As far as the Italian with no Face (must have lost it shaving), engine power is measured in a term called Horsepower. The 8.1 G.M. engine has more horsepower than any diesel engine offered in a pickup.

You are correct in saying that the vortec 8100 has more horsepower in stock form than any of the 3 diesels available in the US light duty truck market. Now, please explain why that engine is rated to tow less than the (by your standards of engine power) lower powered diesel engines? The reason, of course, is that horsepower is only one measurement of engine power. It is also a measurement that is derived from a formula applied to another form of engine power measurement called torque....AND....Regardless what you say, think, or feel about horsepower versus torque, the diesels have more available torque. It must be that the torque output of these engines has just a tiny bit to do with the irrefutable fact that they are rated to tow more, with all other things being equal.