Really? I'm not argueing I'm trying to make sure this is right. Yesterday I looked at the leaf springs on an 04 w/ 6.8l and it had just as many as mine. So is the springs different? I just wonder. Not real inportant to me.

 

ok, so during the l18's production in gm's pickups, it saw a few variants in power, but virtually stayed around the same with mild power band differences. in '01, regardless which motors you look at the gm motor had much more power. the most powerful 8.1 put in a pickup (to my knowledge) was the 340@4200 hp and 455 @ 3200 tq. THE MOST DESIRABLE 8.1 was actually lower in power, w/ 325/450 hp/tq @ 4000/2800 rpm respectively (more desireable due to the super-low torque peak). so, either motor had more power than the v10 until 05 where its 362/457 @ 4750/3250 respectively, in which case i suppose you are technically correct, but i might point out that the rpm of the peaks are substantially lower on the 8.1 with very similar peak torque values. not to mention the torque curve of an 8.1 is just what it should look like as a huge displacement motor. so, i guess we're both right, we can both pick a motor that has more hp than the other. but the fact remains that the 8.1 has a more usable power band, keeping rpm lower on huge grades. the l18 was used in trucks from '01 until '09 and was virtually untouched in that time (all power numbers similar between the variants). all this bein said, my point stands, which basically was directed to the guy who said no other gasser compares. in a way hes right, cuz the 8.1 is in a league of its own, as it is tuned to modest levels to say the least. the same exact motor has marine applications with 500+ hp (before the owner decides he wants to mod them further). this basically supports my point that the 6.8 v10 is not some holy experience that can only be shared by others that own the 6.8, because there IS another gasser that can give the same experience, whatever that may be.

 

any and all. use both our light duty trucks as examples. we have similar truck weights, we have similar drag from the drivetrain (similar sized components). i get double the fuel mileage that you get. i wont sit here and tell you what you get, but i can say that i avg 18-20 empty (always avg'd 20-22 with stock injectors and 285's) with a mix of highway/country roads. the lowest i ever get is 15-16 if drive it hard (empty) which i rarely do. so, in 200,000 miles (have 230,000 on truck), at 18 mpg thats 11,111 gallons of fuel. at 200k, you will have burnt 22,222 gallons. now, the different gasses and amounts of those gasses that come out of either of our pipes is debatable whether theyre harmful or not, or which one actually physically emits more / gallon . . . but somethin that cannot be debated is that you burnt twice the amount of a finite resource and undoubtedly emitted copious amounts more "harmful gasses" into the atmosphere than i did.

 

You have to look at the spring code on the door tag to make sure what you (or anyone else for that matter) have.

Your truck could be slightly different than the diesel one, and it'll have the same spring. Or not. The diesel usually does have a heavier spring than the gasser, as long as EVERYTHING is the same. And I do mean everything. XL/XLT/Lariat, bed size, reg/super/crew-cab, plow, heavy-service suspension, it almost seems like the color of the paint does too

 

You can't just say "it can't be debated" and that's that.

Actually, in urban driving, I get around 10, on the highway I get 15, and I get 16+ on long LONG trips.

Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel | US EPA

Using their formula of 2778gr/gal diesel, and 2421gr/gal gasoline, my 10 MPGs would equal the carbon dioxide output of 11.4MPGs for diesel. And that's just carbon dioxide.

If your truck has no EGR, no DPF, and doesn't use ULSD, you are emitting a whole heck of a lot more other crud than I am.

And if you're talking about your 2002 Cummins, you sure in heck are. Which is obviously tuned.

Also, the PRODUCTION of diesel requires more crude oil, and produced more pollution during the refining process.

Now, if you want to compare a brand-new FORD 6.7 Diesel to my V10, I'll admit that it is most likely cleaner, mile-for-mile. But a big old 2002 6-cyl Cummins, no way.

 

There is no doubt that the 8.1 is a beast of a motor, but it does not compare, at least to me, because it was never put in a truck that can take years of hard use.

Torque at a lower rpm is worth less than the same amount at a higher rpm. The higher the rpm its at the greater the HP. I would love to see a dyno graph from a 3v and an 8.1 laid over each other. The V10 makes useable power from 1500 all the way to 5000. I'm not sure about the 8.1.

 

Where do you get torque at higher rpm is better than torque at lower rpm. Tq is tq. Tq @ a given rpm is just that. Tq at engine rpm. Why I question you is because you reach peak tq at a lower rpm than peak hp almost 100% of the time. I can't think of a time when tq peaked higher than hp but just as soon as I say it doesn't someone will prove me wrong. Your engine isn't useing hp to turn the crank. Its useing good ol tq. I still haven't found any advantage of higher rpms yet.

 

The trucks I'm compairing is the same all the way down to the paint but for the engine. Same number of springs everything. On the door both trucks rated for 8800lb gvw. Hmmm oh well. I have the diesel so I'll have the heavest springs anyway. Thanks.

 

Doesn't matter about number of leaves, you have to check the spring code on the door tag. The leaf-sprung trucks have front springs that start at "S" and go all the way to "X". My truck would normally have come with "S" springs, but I have "T" springs because I have the heavy-service suspension package. You can't tell the S springs from the T springs, they both have two leaves.

And, you won't have the "heaviest" springs, unless you have a plow package. The GVWR for the entire Superduty line is 8800 lbs, up to model year 2004 I believe.

The difference is, because you have a diesel, you can haul less than I can before you hit that 8800 lbs

 

That has been covered earlier in this thread, believe it nor

As an example, you can have two electric motors that run a fan in a commercial heating unit. They are both 1HP. One runs at 3600RPM, the other runs at 1800RPM.

If you gear the 3600RPM motor at a 4:1 ratio, you spin the fan at 900RPM. Likewise, gear the 1800RPM motor at 2:1, the fan runs at 900RPM.

The difference is, the 3600RPM motor is putting out half the torque, but still doing the same job.

Meanwhile, the 3600RPM motor is half the size of the 1800RPM motor, saving money on material to manufacture it.

Same principle in vehicle engines. You could have a motor (both diesel or both gas, doesn't matter) that spins twice as fast, puts out half the torque, but as long as you gear correctly for it, it'll do the SAME JOB.

In this discussion, the problem is two different fuel types.

 

And the idea that low RPM is better and higher RPM engines won't last as long.

 

This might help - GM 8.1

 

I gotcha about the springs. I tought leaf spring where leaf springs. Well compairing between say SDs and being the same on 1/2 tons weither they had v6s or v8s. I never knew there was different leaf spring. Thank you for bearing with me. I meant I would have the heavest between the 2 trucks I was compairing. Both are stock and only have the fx4 pkg.
As far as the high rpm goes yea I keep reading it and I disagree with the reason of the problem. The way I see it if you have 2 simular engines that makes the same power but at different rpms. Let's say 3000 rpm at 450 fttq and 6000 rpm @ 450 ftlbs same transmission and same rearend same truck. From the line until whenever "I can't figure the magicual break even point" the 3000 rpm is going to accelerate faster than the 6000 rpm engine. Now there will come a time when the higher rev engine will overcome given the race is long enough.
Our problem is the engines are not anywhere near the same. What we have is 1500-2000? rpm spread. The tq 100+ and hp 30 difference.
560 ftlb @ 2200 rpm
325 hp @ 3600? Rpm

450 ftlbs @ 3200? Rpm
360 ftlbs @ 4500? Rpm is this close to right I can't remember right the 6.8l specs at the moment. I think I'm close enough.
Clearly same tranny same truck same weight the diesel accelerates faster to a point. By that point we're underway. Now. The 6.8l startes to catchup and move on. This of course is on flat ground or at least so what close. High rpm allows you to in most cases use tall gears better. The thing about high rpms is breathing if it NA. Does the 6.8 have a problem getting "winded" I don't know and I don't use it in my argument.
Really what I'm saying is that the higher rpms of tje 3v 6.8l doesn't give it an advantage over the 6.0 or 6.4l psds. These 2 psds has more usable force and its keeps it thru out its curve. I don't know how many feet, yards, miles this holds true. Going uphill loaded gravity, wind and everthing else force is trying to stop the trucks. They are naturally trying to come to a stop. Useing low end tq I can keep accelaration at lower rpms a gear higher and maintain same speed. To me that's an advantage.
Does the 6.8l has a higher top speed? I believe it does.

 

you proved that bill alot of pages back.

 

I comment it this way. Gasoline engines got mandatory catalytic converters like 50 years ago? That was because they have been dumping so many poisons that few more years later and center of Los Angeles would be a death zone.
Diesels on other hand have been always so clean that only in last few years got equipped with converters and particle traps.
Some advanced diesel owners state that they would rather breath their tailpipe exhaust that the air on LA intersections where gasoline engines still prevail
Bottom line -if gasoline lowers didn't learn the truth in last 50 years, I don't think another 20,000 replies here will help them.