6L Ford diesel yeah or nay?

SolarAndWood said:

lukem said:

Consider yourself lucky if you get 20 with a "new" diesel....14- 18 is probably a more realistic number

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Huh, a few mpg might not seem like a lot but as a percentage it is pretty big. I do 11 around town and 16 on the highway now. Makes my paid for truck look even better.

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Heard that, but by the same token, 16 ain't 20 either.

lukem said:

SolarAndWood said:

20 mpg that serves all purposes.

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Consider yourself lucky if you get 20 with a "new" diesel. You might eek that out of an old 5.9 cummins or 7.3, but the DMaxes, 6.7 cummins, and especially newer fords (not sure about the new 6.7) aren't going to get that from what i've seen and the people I've talked to. 14- 18 is probably a more realistic number depending on the truck on what you are doing with it, with fords being on the low end and dodge/chevy on the high end.

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2003 Duramax 2500HD Ext Cab Long Bed 4WD - 19.5MPG average running 75MPH down I-81 (empty, 20 degree weather). Drove it from New York to Alabama and back and loved every turbo-whistlin' second of it. Allison Trans is the clincher tho. You gas boys (except a handful of early lucky 8.1L owners) don't know what you're missing.

Wish that truck was mine but I have to settle for borrowing it from dear old Dad once in a while. He gets hounded all the time to sell it because of the lack of emissions straight-jackets compared to the new trucks.

The emissions "straight jackets" can all be removed. Wonderful thing about computers and the smart kids that know how they work. After removing the smog crap the mpg are right back to where it was. OEM MPG went downhill for all makes in 2007 when the new EPA regs went into effect. With the 2011 model year, the MPG has returned to where it was plus the typical extra power that is totally unnecessary.

Yes, I can get over 20 on the freeway in my 2000 7.3 ford diesel with no emissions controls. When it is working (towing) I get 12 and when in city/short trips I get 15. This compares well with those little half ton trucks even though the diesel has 2400 lbs of legal cargo capacity and can tow almost anything.

Even 2 mpg is more than 10% with a pickup.

The newer light truck diesels would probably get better mileage if there wasn't such an insane power war between the manufacturers. Highbeam's '00 7.3 Powerstroke is grossly under-powered by today's standards. I don't have the numbers handy, but I think the 7.3 is rated a couple hundred less hp than the current powerstroke. I'll do some research to back myself up later.

Flatbedford said:

The newer light truck diesels would probably get better mileage if there wasn't such an insane power war between the manufacturers. Highbeam's '00 7.3 Powerstroke is grossly under-powered by today's standards. I don't have the numbers handy, but I think the 7.3 is rated a couple hundred less hp than the current powerstroke. I'll do some research to back myself up later.

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The funny part about that is the 7.3 will pull anything down the road and get decent mileage doing it. The quest for more HP is a joke. I buy single wheel 3500 series trucks for work, GMC with a 5.7 gas will get 15 16 MPG and has plenty of get and go(probably not for trailer but a loaded reading tool body its great). GM has to go bigger and now we get 6 liter, more power for sure, 11 to 13 MPG tops.You drive a lot like I do and thats alot of money in gas. Rumors of a smaller Duramax in the near future

Wallyworld said:

The funny part about that is the 7.3 will pull anything down the road and get decent mileage doing it. The quest for more HP is a joke. I buy single wheel 3500 series trucks for work, GMC with a 5.7 gas will get 15 16 MPG and has plenty of get and go(probably not for trailer but a loaded reading tool body its great). GM has to go bigger and now we get 6 liter, more power for sure, 11 to 13 MPG tops.You drive a lot like I do and thats alot of money in gas. Rumors of a smaller Duramax in the near future

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I agree. Folks arent happy until they can leave the cruise control on 70 going up a mountain pulling 20k. Everyone seems to love the older 7.3 but everyone wishes it had more power. Several of them in the family. I would have bought one when I got my SD but they are just getting to old for a truck I want to last for a long time (plus I like other things about the newer ones, interior, etc). And the cost of the new diesels are crazy. I ordered a V10 and have no complaints. Its a DD and weekend warrior, runs nice and smooth and quiet, and for all the more I'll haul with it (up to 10k probably max) it does great.

The 6.0 is a good engine with a few issues. After I got the V10 I stopped researching it but at one time I knew all the things to look for... the forums at ford-trucks.com would be invaluable for that... basically if you had a good one you could make it bullitproof by raplacing some of the items ahead of time, but it would cost a few grand to do so. Theres also some pm that needs to be done to avoid some of the other issues (cleaning egr etc).

The 7.3L could certainly hold it's own in the power department with a few aftermarket tweaks. +1 on it's reputation too, everyone who's ever owned one loved it.

I agree that the price premium on the new diesels is quite steep but that's supply and demand for ya.

While the 6.0L has a long list of fixes and preventative maintenance items to make it bulletproof, I find it irritating to have to do all that to a stock engine that's supposed to be a workhorse. I'm not one to lay out several grand to get the same performance and reliability that the Duramax and Cummins came with from the factory.

Can't argue with ya there.

The premium is pretty steep on a new one, although you do get proportionaly more on the trade in value so it mostly balances out. But still the up front was just too much for me. Heck to afford a new truck I had to get the bottom trim package with no power nothing and a manual transmission (although I dont mind and even prefer it that way anyhow).

Only one problem with manual trans in todays trucks. They aren't rated to tow/haul as much as an auto. They can be made so but that's more $$ and by then, well, you could've saved yourself the work and bought the auto. Plus the auto trans in todays diesel pickups is soooooooo good that they really are worth the cash.

That said, I had the pleasure of working a 1992 Dodge 3500 with the old 12 valve Cummins and a manual gearbox. The bark it let out everytime you let up on the clutch and applied throttle was addicting!

I wonder whether its the new emissions requirements or the hp race that has has effected mileage in light truck diesels. The 7.3 Powerstroke peaked at 275 hp / 525 lb/ft. The current 6.7 Powerstroke is rated at 400 hp / 800 lb/ft. You have to burn more fuel to get more power. I wonder what kind of mileage the 6.7 would get if it were detuned to 7.3 output.

http://www.internationalpowerstroke.com/compare.html

BTW my '00 V10 has a higher rated hp than the Powerstroke of the same model year 310 hp / 425 lb/ft. Not as much torque though.

Flatbedford said:

I wonder whether its the new emissions requirements or the hp race that has has effected mileage in light truck diesels. The 7.3 Powerstroke peaked at 275 hp / 525 lb/ft. The current 6.7 Powerstroke is rated at 400 hp / 800 lb/ft. You have to burn more fuel to get more power. I wonder what kind of mileage the 6.7 would get if it were detuned to 7.3 output.

http://www.internationalpowerstroke.com/compare.html

BTW my '00 V10 has a higher rated hp than the Powerstroke of the same model year 310 hp / 425 lb/ft. Not as much torque though.

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It's both. The 7.3 was scrapped (so I've been told) because it couldn't be made to pass CA emissions standards.

Flatbedford said:

I wonder whether its the new emissions requirements or the hp race that has has effected mileage in light truck diesels. The 7.3 Powerstroke peaked at 275 hp / 525 lb/ft. The current 6.7 Powerstroke is rated at 400 hp / 800 lb/ft. You have to burn more fuel to get more power. I wonder what kind of mileage the 6.7 would get if it were detuned to 7.3 output.

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Dont forget you have to use that extra power for it to consume more fuel though, thats why mileage on most vehicles today isnt that much worse than 20 years ago although the average HP is a lot more. (Yeah I know some diesels are getting less but thats more emissions related than higher output - think more of gassers and cars for my example here). I guess what I am trying to say if your cruising on the highway at 65 your only using lets say 25 hp. Just because your motor is rated to 200 or 300 or whatever doesnt mean its making that all the time, it is just a peak number. All other things equal your going to be using the same amount of power at a given speed regardless how much the motor makes... or else you'd be going faster. Smaller cars and such are only using about 10hp at highway speeds. You start using more fuel though when you use that extra power to accelerate faster, or haul more weight or something, or by making the vehicle bigger or heavier, etc.

MasterMech said:

Only one problem with manual trans in todays trucks. They aren't rated to tow/haul as much as an auto. They can be made so but that's more $$ and by then, well, you could've saved yourself the work and bought the auto. Plus the auto trans in todays diesel pickups is soooooooo good that they really are worth the cash.

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Well I'm not a fan of the autos, but thats just personal preference. I did have to go through the extra hassle and 2 month wait of custom ordering my truck built with the 6-speed since the dealers arent stocking any handshackers any more (actually as of 2011 Ford has dropped it all together - auto only now, except for chassis cabs that still can be had with the V10 I think). The ratings are less, yes, but thats only a 'problem' I guess if you are going over them. I'm mostly familiar with Fords so cant really speak of the others, but the rating difference when I ordered mine was pretty small between the ZF6 speed and Torqueshift, and well over what I needed anyhow. Looking at used trucks I would definitely go for a handshacker if looking at a pre-torqueshift auto (prior to 2005 with the 4RW100). My cousin has the truck I wanted, pretty much identical to mine except duals and the 7.3. We both are 1 ton 4x4 crew cab, long bed, with manual 6 spd trans, hubs, and transfer case. If only it had the interior of the newer trucks and 10 years less wear on the body and other parts, it would be my perfect truck anyhow. But I think we are going off on a tangent here.

Good decision on not buying the Ford. That 6 liter motor was a nightmare for everyone I knew that owned one. The 7.3 Powerstroke was a bulletproof motor but a little underpowered and getting harder to find due to rust.

I'm on my third Duramax, all with the Allison transmission. I'm at 43,000 miles on my 2008 and the mileage is getting better and better, now I'm getting around 20 on trips and 17 around town. If I were you I'd look at pre-2008 Duramax's since the particulate filter (DPF) hurts the mileage a little.

The Cummins is a very good motor but Dodge has always struggled with their auto transmissions. And they ride very rough compared to the Duramax.

Flatbedford said:

The newer light truck diesels would probably get better mileage if there wasn't such an insane power war between the manufacturers. Highbeam's '00 7.3 Powerstroke is grossly under-powered by today's standards. I don't have the numbers handy, but I think the 7.3 is rated a couple hundred less hp than the current powerstroke. I'll do some research to back myself up later.

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My valve cover sticker says 265 HP at 2700 RPM. The new trucks are heavier, rev higher (that's where most HP comes from), and waste fuel on emissions chokepoints like running the exhaust through a huge filter to keep the soot out and then dumping fuel into that bif filter to burn off the accumulated soot.

A simple 295$ dollar chip allows my 2000 model year truck to gain 100 more HP at the rear wheels. The engine has no problem with that, the transmission isn't quite up to the task though. Folks that have added HP this way report the same mpg so long as they can keep from hot rodding it.

Somewhere after 1999 I think Ford made a change to the auto trans behind the 7.3 for durability reasons. Not sure where the break is tho.

Ford never improved the trans behind the 7.3 after 99. They all use the 4r100 from 99 on up to the switch to the 6 liter. The 4r100 isn't bad at stock power levels and it can be built to withstand all power that the 7.3 can make for about 50% more than the cost of a ford rebuilt trans.

Early 7.3s, 97 and back, used a E40d trans that was even weaker. Maybe that was the switch you were referring to?

Whatever you do, don't get a naturally aspirated powerstroke, or anything GM pre-Duramax. I used to drive nat-asp powerstroke and it was a complete dog.

Highbeam said:

Ford never improved the trans behind the 7.3 after 99. They all use the 4r100 from 99 on up to the switch to the 6 liter. The 4r100 isn't bad at stock power levels and it can be built to withstand all power that the 7.3 can make for about 50% more than the cost of a ford rebuilt trans.

Early 7.3s, 97 and back, used a E40d trans that was even weaker. Maybe that was the switch you were referring to?

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I think that's what I'm remembering.

lukem said:

Whatever you do, don't get a naturally aspirated powerstroke, or anything GM pre-Duramax. I used to drive nat-asp powerstroke and it was a complete dog.

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Before we fell in love with turbo's, the diesel's selling point was fuel economy, not horsepower. I'd take an old Ford 6.9, 7.3, or GM's 6.2/6.5 for just a plain old wood hauler anyday. Especially if there was a dump body on it.

That said, spooling up one of the modern diesels and letting the trans click off 6 gears in rapid sucession is rediculously addicting! :coolgrin:

SolarAndWood said:

I average 12 with mixed driving. 16 is pure highway. With my 18,000 miles a year at 4 bucks a gallon, there is $2400/yr on the table if the engine doesn't fail and if it gets 20 as claimed. My neighbor does that with his mid 2000s Duramax 3500. But something tells me our driving styles are a little different.

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I can settle the gas mileage debate. I have a 2003 F350 with the 6.0 diesel and I get 16.3 mpg average with mixed use.

So far, I have 26,000 miles on the truck and have only had a single problem with it that I fixed in 4 hours under the hood. Oh yeah, I also had to change the brakes and rotors because they rusted up pretty good from sitting around one winter.

Anyway, I am hoping that I am one of the lucky ones with this engine, because a new truck is ridiculously expensive nowadays.

lukem said:

Whatever you do, don't get a naturally aspirated powerstroke, or anything GM pre-Duramax. I used to drive nat-asp powerstroke and it was a complete dog.

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They weren't called powerstrokes until about 1996 when the 7.3s became direct injected and turbo equipped. Prior to that the old 6.9/7.3 was an indirect injected engine with a regular old tractor style injection pump. It was gutless by any standards and mpg was not very good really, the only manual was a 4 speed. They sounded gurgly too and smoked. For a year or two before the powerstroke the 7.3 diesel IDI (indirect injection) did have a turbo added on to it but it was still way behind the powerstroke that came later. Banks made a turbo kit for the older non-turbo ford diesels. Parts are cheap and the old ford diesels are actually fairly dependable and easy to work on. As you know, until the 2011 model year, ford diesels are actually made by international/navistar.

The chevy pickup diesels before the dmax were made by detroit diesel. The newer duramax is made by isuzu. I believe that they still make and use the 6.5 turbo diesels in the military humvees so parts availability will be good. A similar thing to the ford happened where the old original 6.2 was IDI and non-turbo with a simple injection pump and very low power, cheap parts, and easy to work on. The newer 6.5 turbo never really became powerful, dependable, or good and was completely dropped in GMs civilian market for the dmax in the early 2000s.

Now the cummins. Well, they always had it figured out. Much better direct injected engine from the start that was capable of plenty of power but detuned to try and prevent blowing up the dodge trucks of the era. Even the original early 90s cummins 12-valve engines are still sought after and used for conversions, they were always far superior to the dodge truck. Dodge would not be here today if they hadn't chosen cummins for their diesel.

LOL +1 on the old Dodge trucks, you could buy one Cummins and wear out 3 or 4 trucks on that motor!