how does the Ford 6.0 Diesel compare with the 7.3? - Page 2 - PeachParts Mercedes-Benz Forum

sixto · #16 03-22-2008, 07:07 PM

Quote:

Originally Posted by aklim

So why not get the gas version? You will pay a premium for diesel and if you are not towing, what is the point?

I should ask what mpg the 7.3 gets in highway cruising. Our 6.5 gets at least 19mpg highway. With current prices of $3.70/gal for gas and $4.20/gal for Diesel, We'd need a gasser that gets over 16mpg highway to be cost competitive. I don't think I can coax 16mpg out of a 5.4 Excursion. Even keeping within 5mph of the limit, the slowest I can drive without falling asleep, I can't get more than 28mpg out of the 300D. I don't accelerate hard but my big vice is AC. Must have AC.

Sixto
87 300D

daveuz · #17 03-22-2008, 07:08 PM

Alkim, sounds like a very nice set up!. I too went to Jody at DP-tuner. I just run a Re-flashed PCM with his Econo program. Other than that some cleaning of the exhaust pipe unit and no engine fan.

sixto · #18 03-22-2008, 07:10 PM

Quote:

Originally Posted by aklim

My reasoning is that if he isn't towing, it will be fine to go with gas. Why have the hassle of having to plug it in when cold, harder to find fuel, messier pumps, etc, etc?

Ah, I don't have to contend with weather and I've yet to have a problem finding a Diesel station. Lots of wannabe Texans driving Lariats and Big Horns around here

Sixto
87 300D

aklim · #19 03-22-2008, 07:11 PM

Quote:

Originally Posted by sixto

I should ask what mpg the 7.3 gets in highway cruising.

About 16-17. First thing you need to know is that the mileage meter is commonly called the "Lie-O-Meter". I hand calculate the mileage at 16-17. It tells me I get 22-24. Of course, the chip I have will screw with it

aklim · #20 03-22-2008, 07:12 PM

Quote:

Originally Posted by daveuz

Alkim, sounds like a very nice set up!. I too went to Jody at DP-tuner. I just run a Re-flashed PCM with his Econo program. Other than that some cleaning of the exhaust pipe unit and no engine fan.

Ah, but Sir, there is more. Planning for bigger sticks and bidding on a van turbo.

However, because of PMRs I am limited to about 400 HP

sixto · #21 03-22-2008, 07:12 PM

Quote:

Originally Posted by aklim

Oil change is 15-16 quarts at a time. Change that ever 3000 and if you don't have a reason, you are screwing yourself. Also, with diesel, you have another issue. HUEI systems are totally dependent on oil. Cold temps and the oil doesn't work as well. So, you have to switch to synthetic oil.

Good heavens! The 6.5 takes 8 quarts like any MB. 16 quarts every 3000 miles could be the deal breaker! I guess we'll be staying the 'burb for a while.

Sixto
87 300D

aklim · #22 03-22-2008, 07:15 PM

Quote:

Originally Posted by sixto

Good heavens! The 6.5 takes 8 quarts like any MB. 16 quarts every 3000 miles could be the deal breaker! I guess we'll be staying the 'burb for a while.

Sixto
87 300D

Well, with Shell Rotella Synthetic, you can extend it to 5000 miles.

KarTek · #23 03-22-2008, 08:49 PM

7.3 - Rougher, less refined, 16 valves, good on bio or WVO.

Weaknesses (Only an issue when you're looking for more performance):

High pressure oil pump
Powdered metal rods (on late 2001's and up)
Closed ended fueling system
Automatic transmission.
Small turbo (early '99's)

6.0 - Smooth, better HUEI system, 32 valves, VV turbo, nice torque-shift tranny, easier to get more power for cheaper.

Weaknesses:

Head gaskets and oil leaks on '03-'04's

My '00 gets about 18 MPG on the highway and 15 intown.

daveuz · #24 03-22-2008, 08:59 PM

Quote:

Originally Posted by aklim

About 16-17. First thing you need to know is that the mileage meter is commonly called the "Lie-O-Meter". I hand calculate the mileage at 16-17. It tells me I get 22-24. Of course, the chip I have will screw with it

Alkim, is yours a 4wd? I wonder if Sixto would opt for the 2wd version. I would expect slightly better fuel mileage with the 2wd and a good PCM flash.

Bio300TDTdriver · #25 03-22-2008, 09:45 PM

A Cummins takes 12 quarts. If you use oil analysis you can go more than 5000 with synthetics, Mobil 1 or Amsoil.

aklim · #26 03-22-2008, 10:11 PM

Quote:

Originally Posted by KarTek

7.3 - Rougher, less refined, 16 valves, good on bio or WVO.

High pressure oil pump

Powdered metal rods (on late 2001's and up)

Closed ended fueling system

Automatic transmission.

Head gaskets and oil leaks on '03-'04's

IMO, with WVO you best heat it up real good first or it better be warm outside. Those are $200-300 injectors we are talking about.

HPOP isn't that bad. On the early 99s you could be having a 15 degree swash plate in the HPOP. After that, you are having a 17 deg HPOP. Now, I have stacked HPOPs

You are limited to about 400HP with the PMRs.

Diesel Innovations or ITP has a fix for that. Now, you can be a cheap bastard and go with a Veggiestroke piece for under $100, IIRC. That equalizes the fuel flow so you don't get so much cackling with the fuel starvation on #8. I prefer the ITP or DI approach since I get to bump up the fuel pressure with the external regulator.

The 4R100 can be fixed by BTS for $4100. If you drive it there, he installs it free and his receptionist is a hottie. Otherwise, he ships it to you and dares you to break it. 2 yr unlimited warranty. After that, you pay for shipping and he fixes it for you. Last trans you are paying for.

I think the variable vane turbos were an issue too. They tend to coke up. BTW, they do call it the "6 leaker"

aklim · #27 03-22-2008, 10:12 PM

Quote:

Originally Posted by daveuz

Alkim, is yours a 4wd? I wonder if Sixto would opt for the 2wd version. I would expect slightly better fuel mileage with the 2wd and a good PCM flash.

Yes it is 4WD. Sixto could go for the 2WD since he is where he is but the resale might not be so good.

Bio300TDTdriver · #28 03-22-2008, 10:17 PM

Quote:

Originally Posted by aklim

IMO, with WVO you best heat it up real good first or it better be warm outside. Those are $200-300 injectors we are talking about.

HPOP isn't that bad. On the early 99s you could be having a 15 degree swash plate in the HPOP. After that, you are having a 17 deg HPOP. Now, I have stacked HPOPs

You are limited to about 400HP with the PMRs.

Diesel Innovations or ITP has a fix for that. Now, you can be a cheap bastard and go with a Veggiestroke piece for under $100, IIRC. That equalizes the fuel flow so you don't get so much cackling with the fuel starvation on #8. I prefer the ITP or DI approach since I get to bump up the fuel pressure with the external regulator.

The 4R100 can be fixed by BTS for $4100. If you drive it there, he installs it free and his receptionist is a hottie. Otherwise, he ships it to you and dares you to break it. 2 yr unlimited warranty. After that, you pay for shipping and he fixes it for you. Last trans you are paying for.

I think the variable vane turbos were an issue too. They tend to coke up. BTW, they do call it the "6 leaker"

AKA PowerJoke

KarTek · #29 03-24-2008, 12:21 PM

Quote:

Originally Posted by aklim

IMO, with WVO you best heat it up real good first or it better be warm outside. Those are $200-300 injectors we are talking about.

HPOP isn't that bad. On the early 99s you could be having a 15 degree swash plate in the HPOP. After that, you are having a 17 deg HPOP. Now, I have stacked HPOPs

You are limited to about 400HP with the PMRs.

Diesel Innovations or ITP has a fix for that. Now, you can be a cheap bastard and go with a Veggiestroke piece for under $100, IIRC. That equalizes the fuel flow so you don't get so much cackling with the fuel starvation on #8. I prefer the ITP or DI approach since I get to bump up the fuel pressure with the external regulator.

The 4R100 can be fixed by BTS for $4100. If you drive it there, he installs it free and his receptionist is a hottie. Otherwise, he ships it to you and dares you to break it. 2 yr unlimited warranty. After that, you pay for shipping and he fixes it for you. Last trans you are paying for.

I think the variable vane turbos were an issue too. They tend to coke up. BTW, they do call it the "6 leaker"

My truck flat out falls on it's face at higher RPM's because of the poor HPOP supply. It's a shame that you have to put thousands of dollars into a truck to make it the way it should have been from the factory...

All of this of course, is not an issue if you just want reliable stock performance... Oh wait, I forgot about the fragile CPS... There's a recall on them now... Of course, I replaced mine a couple years ago and God knows where the receipt is...

aklim · #30 03-24-2008, 12:29 PM

Quote:

Originally Posted by KarTek

My truck flat out falls on it's face at higher RPM's because of the poor HPOP supply. It's a shame that you have to put thousands of dollars into a truck to make it the way it should have been from the factory...

I don't seem to see that problem when mine was stock. I don't know if you have a weak HPOP to begin with. Dad has a late 99 and it doesn't fall on it's face at higher RPMs.