Here would be a comparison for you, two Allis Chalmers tractors, same size, one gas, one natural aspirated diesel, the diesel out works and uses less fuel than the gas, so what do you have for an explanation to that?
And another point to coinsider, if it were so easy to produce power from a gaser by simply adding a turbo, wouldn't that be done more commonly, as efficiency is mandated by the government with the CAFE standards, so if it was that easy, wouldn't the manufacturers be doing it across the board the way they do on the diesels?
I grew up with old farm tractors, gas, diesel, turbo diesel, and the diesels will run all day on the same fill, while the gas will have to stop at lunch to fill again, and the diesels will pull harder than the gassers, with or without the turbo. Furel injection on the gassers has helped immensely on efficiency and power both, but to say the diesels are not more efficient and powerful is plain folly. At the time, they weren't putting the real effort into making the diesel trucks because the market wasn't demanding them. Now, you can get a simple chip and minor upgrades and the diesel will outperform any gasser on the road, unless it has had major internal modifications. Add a turbo, and yes, a gesser will do better, but won't be able to hold up with the diesels with simply a power chip and exhaust upgrade. Teh efficiency part of it comes into play quite strong. If you study it at all, diesels are at 40% efficiency without a turbo, while gassers are at 25%. There obviously is something to be said right there... And the OEM have put turbos and superchargers on some cars, but just haven't really made it work good enough to make it work for every car apparently...

 

What the heck did you grow on that farm??? Smoke it much??

Did you read ANY of the prior posts???



Did you read ANY of the prior posts???

Could care less about old farm tractors.........I gave you a list of underperforming N/A diesels.....you choose to ignore it.


Who in the world said anything about blown gassers being more efficient??
Who mentioned CAFE?? Put down the pipe, dude. There are a lot of blown gassers out there.....both supercharged and turbocharged....a perfect comparison would be to look up the specs on the 2L range of Mitsubishi and Subaru turbos....then compare them to like size VW or Audi TDI's....maybe that'll enlighten you??? I'll help you out....the gassers have WAAAY more power but are FAAAR less efficient.....getting it yet??

I have a near 500 feet pound supercharged Ford 5.4 gasser from the factory that gets about 12 MPG.....could that be the reason blown gassers aren't used more???


Has ANYBODY said different??? In fact that is the MAIN reason diesels are more prevelent in HD applications..........Is there an echo in here??


If you choose to believe that, than all the current examples in the world will not change your mind.

Who has EVER stated diesels are not more efficient??? As far as power, again check out the comparisons....even though I know you won't accept them.

Gee whiz, could that have ANYTHING to do with forced induction???



Absolute hogwash.........IF you could run the same boost numbers without grenading the motor, the gasser will ALWAYS have more power.

You are not accepting the fact that the current diesels are running 2-3X's more boost than a factory blown gasser BECAUSE the gasser wasn't designed to handle that much air.....and it's also why a diesel will weigh 500 pounds more.

If you're trying to state VE (volumetric efficiency) I've never seen any numbers as low as 25%.......I've seen upwards of 80-90% VE.
Please post a source, otherwise those numbers make no sense.


Could it be beacuse when you add forced induction on a gasser it uses more fuel???

Why aren't the Mazdaspeed turbo cars diesel?? How about Subaru turbos? Mitsubishi turbos? The late great supercharged Ford Lightning??

Why don't racing assoc. run diesels.....heck, according to some of you guys the Olds normally aspirated 350 diesel should be faster than a 350 small block Chevy.

 

Once again the gas vs diesel debate has gotten emotional.

 

yup.


IBTL :lol:

(In Before The Lock)

 

Emotional?? Sorry that my poor attempt at levity comes across that way......


I will admit to being perplexed when people pull comments out of thin air and try to make some valid point on an issue that never even existed...

 

Yes, let's try to remain calm...please. I don't want to feel like I am moderating in the Super Duty forum.

-Matt

 

Then you haven't heard about the 10 second diesel dragsters, or the ones that Audi is running that are winning the LeMans races.... You choose some of the OLDER diesels to prove your point, but aren't recognizing the newer ones that are winning races against the gassers that are cranked up as well.Bloomberg It would seem you are as stubborn about changing your ideas as you accuse me of being, but I drive one of those old 6.9's, and it may not be a race machine, but it certainly can pull it's share of weight, well over the specs printed in the books, and, at stock setup, the 460 didn't have that much more of a rating in the same age.
In regards to the figures I gave , that is FUEL efficiency, which unless you are a fool, DOES matter. The 460 my sister ran to pull her horse trailer, with overdrive, got a best of 9 pulling the trailer, while the ol' 6.9 I have got 12,without overdrive. As far as power went, it really wasn't a lot of difference. The Cummins in the 92 I set up for her will leave the 460 behind on the hills... it isn't turnd up much either. No chip, all mechanical controlled.
It really comes down to what you want to do, if you want to haul heavy trailers and such, it is hard to truly beat a diesel when you look at the power potential and the fuel efficiency. If you want to race it, gassers have dominated, but that is changing.
I realize that most stock motors aren't set up with turbos, but the fact remains that they could be, and as you point out, thewre are some that are, but if your argument stands true, things like the Le Mans race should not happen, but yet it does.

 

Does this debate come up often over there, or just heated debate's in general? I've never been.

 

It comes up from time to time with the Super Duty owners. Seems to come and go in spurts.

-Matt

 

Now that you mention it, Matt, it has been a while. You've just inspired me to head-on over there right now and post a new thread. Howz this for a title; "Gas Or Diesel - Which One Kicks Butt?"

 

Seriously, what is wrong with you???

Why do you keep bringing up fuel economy and efficiency??

NOBODY, and that includes me, has contested the diesel is more efficient, runs at lower RPM and will last a bit longer. Where do you keep coming up that that is a topic of debate???

If you want to use Audi's win and a few bombed trucks as your examples, knock yourself out. The bottom line with the bombed trucks is what I've now said ad nauseum......they have insane amounts of boost. Why can you not accept this???

The Audi example is a SINGLE engineering masterpiece......I suppose the F1 and IRL cars will now all be running diesels next...

Maybe Top Fuel will also start using compression ignition also..


Yes, I did use some older examples, but you convienently left out the modern comparisons;

The Subaru, Mitsubishi, Lightning, Neon SRT-4 etc....if you honestly believe a diesel running the same boost and same displacement can compete with these motors then you are sadly delusional.

If you believe any normally aspirated diesel (I concede that I cannot think of any modern versions) can compete with same size N/A gasser....see above.


The fact that modern diesels are built to run HIGH boost pressures, the fact that diesel fuel can run in that environment relatively cheaply are the reasons the oil burners are making the power they are.

It's just not feasible to run 30 pounds of boost in a gasser. .....but if you did, it would make the diesel power numbers look silly.

No manufacturer is going to build a 1000 pound gasser engine to handle those pressures. And if they did, there is no readily available fuel to run that motor.


99.99999999 percent of all REAL race vehicles are compression ignition....there is a reason for that.

 

There are actually a handful of 6 (six) second diesel rails out there.

 

Links????

When they are in the 4's .......I'll buy Fellro a beer.

 

sure, make me work... I saw them on TV, I'll try to find links to some 6 seconders. I'll post them if I do. Oddly, the latest stat I could find is the 7.98 second run from 2004

http://www.cumminsracing.com/

If this one does 200 mph, it should be in the 6's
http://www.scheiddieselmotorsports.com/ScheiddieselMotorsports/drag.html

Thought this was interesting...

http://www.gizmag.com/go/5746/

 

What a stupid debate. You are comparing apples to oranges. Don't bring top fuel into this they run nitro methane, not gas or diesel.

Look it is very simple. Gas has a limit of how high the compression can be. That is about 16:1. ANything higher than that and you can no longer control igintion. In addition because gas burns much faster that diesel you you have much short stroke engines. This allows for more rpms and more hp.

Because diesel takes that much longer to burn for the most part longer stroke motors are the norm. This means limited RPM's. In addtion the compression ratio for a diesel starts at 14:1 and goes as high as 25:1 in production vehicles today. to handle these compression ratios the engine are heavy, 100's of pounds heavier. Wiegh my 6 liter small block against the 6 liter PSD.

In almost all cases the gas engine will be quicker and faster until you reach the limitations of gas, i.e. to high of compression, stroke gets to long for an effecient burn. This is true in all cases if you don't want to put reliability into the equation. I mean have you ever seen a gas engine that is 3 storys tall. I have seen a diesel this tall though.

But within our normal everday limitation gas will always make more power. An example of this is my LS2 6 liter engine against the 6.0 PSD. Stock I have 400/400 at the engine where the PSD is if I remember right 315/575? But it has a turbo charger. Well I am think of turbo charging my Vette. This is a bolt on kit, no internal changes made to the motor. Expected RWHP/Tq 570/570. In otherwords about 680/680 at the crank.

Would I ever want to tow with this setup, NO!!!!! I'm making this torque past the redline of the PSD. I hope I never have to tow anything and spin a motor at 4500rpms. Could it, yes with ease, the power is there. BUt how long will the engine last if for every 6% grade I have to climb I have the engine at 4500 rpms.

And that is why we have diesel, it is fantastic because it can make big numbers at much less rpms than gas given the same CI. But you give up performance, i.e. quickness and speed in return for reliability.

Anyway now look what you made me do. Each has its application and those applications really don't cross.