Chevy/GMC Van w/Little Diesel Rocking the MPG?

[cortttt]

Check this out

Never thought that little diesel would be this effective. Does anyone else have one?  From EcoModder Forums

https://ecomodder.com/forum/showthread.php/input-ecomodding-2-8-duramax-van-36421.html

[font=verdana, geneva, lucida,]Recently purchased a Chevy 2500 [/font][font=verdana, geneva, lucida,]Full Size[/font][font=verdana, geneva, lucida,] van with the 2.8 Duramax, 8 speed Allison auto trans. Fuel mileage is really impressive. I have about 5000 miles on it, running about 7500 lbs to 8000 lbs GVW. With a full tank of driving in city of Chicago traffic (no burbs) we are getting about 21 mpg. Just took it out on a short highway trip and it's getting about 27 mpg at 65 mph and about 31 at 70 mph. At about 67 mph it upshifts and rpms drop from 2100 to 1500. [/font]

[font=verdana, geneva, lucida,]I've also noticed it appears the trans is programmed specifically for heavy loads.... it holds low gears for a long time before upshifting. [/font]

 

[cortttt]

More from that Forum

This is not a very well known option since it was new on the 2017 full size GM vans.
This vehicle is used to carry heavy loads typically running about 7500 lbs Gross weight, but can handle up to 8600 lbs. We currently have about 6500 miles on it.

Actual MPG Figures (running loaded at about 7500lbs)

City 20 to 21 (in city of Chicago)

Highway at 60 mph, a little over 27MPG

Highway at 70 mph, 30.3 MPG

The 8 speed Allison trans does not shift up to 8 gear until 67 mph, so the engine runs about 2100 rpm at 65, and about 1500 rpm at 70

This mileage is about double the 6.0 L gas v-8, yet this little engine can really get this monster vehicle moving around town since it develops about 325 lb ft of torque at only 1500 rpm ( about 100 HP), about the same as the 6.0 but at lower RPM. ( both engines are about 370 lb ft peak torque)
This is the same Diesel in the colorado/ canyon pick ups, but they only have a 6 speed. From what I read, we are getting about the same mileage as the pickups, but with several thousand lbs more weight and much bigger drag.

If you need to haul a lot of weight all the time and be able to tow trailers with a full framed vehicle., there is finally a really good alternative. Payback due to fuel savings for the optional diesel is only about 18 months when driving about 20,000 miles per year.
Those that have heard about it are already starting to clamber for the engine to be installed in the full size pickups. This engine will be probably destroy Ford's turbo v-6 truck market, since the six gets horrible mileage when carrying heavy loads and is only rated at 24 mpg highway.

and
https://ecomodder.com/forum/showthread.php/2017-chevy-fullsize-van-2-8-hit-33-a-36555.html

Finally had some longer highway drive time and found out just what it could do. Full size Express Cargo 2500 running about 7500lbs GVW with 2.8 diesel, humid 90 F Outdoor, AC running. Was running behind a semi much of the time, but not too close, so that definitely helped. Hit as high as 35 for shorter stretches but at about 65mph over about 60 miles averaged out to about 33.3 mpg on the dash readout. This was running on fairly flat land (northern Il just west of Chicago). Came out to about 32.3MPG once I exited the highway in Chicago and hit local streets.

Not mods yet. Hope to get better shocks, some front end aero (grill air flow improvements, short belly pan) and get the tranny reprogrammed to stay in high gear below 65.

 

[ckelly78z]

That's pretty good mileage for a heavy vehicle, does it have any acceleration ?

My 6.0L diesel Excursion averaged 18.5 mpg while running 75 mph with 6 people, luggage, and bicycles. It still knocks down 13 mpg pulling our 32' loaded camper.

 

[cortttt]

Impressive from the Excursion

Someone on this forum test-drove the little diesel and reported it was fast off the mark as I remember but that's all I've heard. 

This guy did not like it on the highway though

http://www.dieselplace.com/forum/76-speciality-forums/218-vans/905809-2-8-d-max-road-test.html

I found one on a lot and took it for a nice test drive. I am very disappointed in this thing and will not be buying one. 
[font=verdana, geneva, lucida,]1- power. I knew going into it that power was way down but the 8speed gave me hope. In town it was ok, on the highway it just didn't have it at all. Merging with it loaded up would be much worse, towing forget about it.[/font]
[font=verdana, geneva, lucida,]2- The exhaust brake didn't have much holdback at all, even being an empty van which I thought was odd. [/font]
[font=verdana, geneva, lucida,]3- The fuel door houses the DEF fill and it's cramped, under the hood like on the pickups would be better if they didn't want to retool for a bigger fuel door.[/font]
[font=verdana, geneva, lucida,]Maybe a tune would make it bearable but not sure.[/font][font=verdana, geneva, lucida,] [/font]

On the other hand the other guy had it loaded it and didn't mention any problems

[font=verdana, geneva, lucida,]Here's another account[/font]

https://expeditionportal.com/forum/threads/2018-chevy-express-2-8-duramax.196046/


It's peppy, it sounds good, shifts nice. I didn't get it on the highway. It has all, if not most, of the options. It's used with less than 4000 miles. My only concerns would be the IFS and 3" lift. I don't know if any larger tires could be put on with those fenders. They are running 285/70R17s. I'm not saying I want to or need to, but the option may not be there anyway.

[font=verdana, geneva, lucida,][size=small]It's a bit out of my price range for now but I'll be watching out for them.[/font][/size]

[font=verdana, geneva, lucida,][size=small]And another[/font][/size]

[font=verdana, geneva, lucida,][size=small]https://www.dieselplace.com/forum/63-gm-diesel-engines/761-2-8l-duramax/950042-2-8-express-vans.html[/font][/size]

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[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,]I happened to notice the FedEx driver was driving an Express with the 2.8 Duramax the other day. I asked him about it and he loves it. Great mileage and good power. Anybody else have one or has driven one? [/font][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,]But another person said low power on the highway[/font][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]I test drove one, the motor just doesn’t cut it. Highway driving was horrible even empty, if I had it loaded like my van is now it would be worse.[/font][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]And a contrary viewpoint! [/font][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]We are typically running about 7500 lbs GVW in Chicago traffic and also 100 mile runs on the highway. The little motor launches the van quite well, since it has way more bottom end than typical gas v-8's (325 ft lbs @ 1500 rpm, 370 @2000). In the city, it drives about the same as the 5.4 E 250 it replaced. On the highway, no trouble merging and accelerating while loaded. It’s no race car, but it’s fine.[/font][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]Very impressive MPG! 30 MPG on the highway - who would have thought?[/font][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]Fuel Economy is exceptional when heavily loaded. We run about 20 to 21 mpg city, and holding a steady 66 mph (at 65 it will downshift to 7th) we just got 33.3 mpg in humid 90 weather with A/C on over 60 miles, while running behind a semi, but not too close. This is probably about the best anyone could get running without any mods, as I had the speed control set at slightly over 65 to keep the tranny in 8th and then added a little extra as needed to maintain driving distance behind the semi. At this speed, the engine is engine running 1600 rpm (about 100 hp). [/font][/font][/size][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]On heavier grades, such as coming out of a river valley, it would downshift to 7th to maintain speed (2100 rpm/ 150 hp), but otherwise would stay in 8th. This is on relatively flat interstate of the Midwest. On open road without trailing a semi, we get a little over 30. At about 55 to 60 mph in heavy highway traffic entering a big city about 31.5 to 32 mpg...the other traffic helps pull and push you along due to drafting etc. [/font]

[font=verdana, geneva, lucida,]I've been hoping for a small diesel in a full size van for over 15 years. It provides the torque needed to get heavy loads moving, but sips fuel like a compact car.....a perfect combo for tradespeople. The big diesels never made any sense for regular tradesmen, since they don't almost never pull 15000 lb trailers, which I suspect is probably about 98% of the truck and van buyers. For that matter, must truck/van/ suv's are not carrying more than a couple of people, so it's about time a drive train was offered that fits this need quite well.[/font][/font][/size][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,]This guy is a heavy driver - check out the cost returns...I don't know if he's figuring in higher maintenance costs - more oil, DEF but I assume that he is...[/font]

[font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]My only gripes have been the crappy factory shocks (this thing feels like our 2007 Jeep GC with 180,000 miles on it with the original struts) and the fact that the tranny holds low gears way too long. In city traffic this occurs about 35 MPH and it will hold the engine at about 2200 rpm until you accelerate to 37 mph, and on the highway....the trans will not upshift to high gear until 67 mph. On the highway it appears to be about a 10% hit in fuel economy at 65. In the city it’s a little harder to tell, but running 2200 rpm when you only need 1500 rpm or less can't be too good for economy. Again this is running about 7500 lb. GVW.[/font][/font][/size]

[font=verdana, geneva, lucida,]With the 20,000 miles per year we put on vans, the payback for the diesel upgrade is only about 18 months. If we keep the vehicle for 12 years (my daily driver is a 93), we should save about $30,000.00 on fuel costs over the 6.0 l v-8's that we have in other vans. The mileage is about double of the v-8s, maybe even more than double on the highway. [/font]

[font=verdana, geneva, lucida,]I do plan to complete some aero mods on the van that should bump the fuel economy up some more, since GM has done very little in this department and there's is a lot of room for improvement. I expect low to mid 30's mileage could be regularly attained with a loaded van, and maybe even better if running lighter.[/font]

[font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]With the couple exceptions noted above… shocks, trans holding gears too long and poor aero… this is a really good combination. While mileage is still way behind full size service vans sold in Europe (they get about 40 to 45 mpg with 1.4 L turbo diesels), for a heavy full framed vehicle this is exceptional. We will be buying more of these to replace the 6.0l gas equipped vans we have in service. [/font][/font][/size]

[font=verdana, geneva, lucida,]Nice! [/font]

 

[JD GUMBEE]

Ecomodder is loaded with people who do things like shut their diesels off at every stop light, while going downhill and they try not to use brakes...letting the vehicles coast to a stop, with the motor off.
(Very bad for the engine.)

I can also tell you the "baby duramax" is not a Duramax in miniature. Too soon to see the long term data, but they are not longevity-designed like a B series Cummins.

Those numbers seem way out of line. Those dash MPG meters are rarely accurate.
(Not to mention his admission of drafting behind big trucks.)

None of the factory reps are claiming anything near this MPG. (30MPG in a one ton van would be a game-changer for fleets.)

I would not trust this info until I took one for an extended test drive and topped the tank to see how much it used.

 

[cortttt]

Impressive from the Excursion

Someone on this forum test-drove the little diesel and reported it was fast off the mark as I remember but that's all I've heard. 

This guy did not like it on the highway though

http://www.dieselplace.com/forum/76-speciality-forums/218-vans/905809-2-8-d-max-road-test.html

I found one on a lot and took it for a nice test drive. I am very disappointed in this thing and will not be buying one. 
[font=verdana, geneva, lucida,]1- power. I knew going into it that power was way down but the 8speed gave me hope. In town it was ok, on the highway it just didn't have it at all. Merging with it loaded up would be much worse, towing forget about it.[/font]
[font=verdana, geneva, lucida,]2- The exhaust brake didn't have much holdback at all, even being an empty van which I thought was odd. [/font]
[font=verdana, geneva, lucida,]3- The fuel door houses the DEF fill and it's cramped, under the hood like on the pickups would be better if they didn't want to retool for a bigger fuel door.[/font]
[font=verdana, geneva, lucida,]Maybe a tune would make it bearable but not sure.[/font][font=verdana, geneva, lucida,] [/font]

On the other hand the other guy had it loaded it and didn't mention any problems

[font=verdana, geneva, lucida,]Here's another account[/font]

https://expeditionportal.com/forum/threads/2018-chevy-express-2-8-duramax.196046/


It's peppy, it sounds good, shifts nice. I didn't get it on the highway. It has all, if not most, of the options. It's used with less than 4000 miles. My only concerns would be the IFS and 3" lift. I don't know if any larger tires could be put on with those fenders. They are running 285/70R17s. I'm not saying I want to or need to, but the option may not be there anyway.

[font=verdana, geneva, lucida,][size=small]It's a bit out of my price range for now but I'll be watching out for them.[/font][/size]

[font=verdana, geneva, lucida,][size=small]And another[/font][/size]

[font=verdana, geneva, lucida,][size=small]https://www.dieselplace.com/forum/63-gm-diesel-engines/761-2-8l-duramax/950042-2-8-express-vans.html[/font][/size]

---

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,]I happened to notice the FedEx driver was driving an Express with the 2.8 Duramax the other day. I asked him about it and he loves it. Great mileage and good power. Anybody else have one or has driven one? [/font][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,]But another person said low power on the highway[/font][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]I test drove one, the motor just doesn’t cut it. Highway driving was horrible even empty, if I had it loaded like my van is now it would be worse.[/font][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]And a contrary viewpoint! [/font][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]We are typically running about 7500 lbs GVW in Chicago traffic and also 100 mile runs on the highway. The little motor launches the van quite well, since it has way more bottom end than typical gas v-8's (325 ft lbs @ 1500 rpm, 370 @2000). In the city, it drives about the same as the 5.4 E 250 it replaced. On the highway, no trouble merging and accelerating while loaded. It’s no race car, but it’s fine.[/font][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]Very impressive MPG! 30 MPG on the highway - who would have thought?[/font][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]Fuel Economy is exceptional when heavily loaded. We run about 20 to 21 mpg city, and holding a steady 66 mph (at 65 it will downshift to 7th) we just got 33.3 mpg in humid 90 weather with A/C on over 60 miles, while running behind a semi, but not too close. This is probably about the best anyone could get running without any mods, as I had the speed control set at slightly over 65 to keep the tranny in 8th and then added a little extra as needed to maintain driving distance behind the semi. At this speed, the engine is engine running 1600 rpm (about 100 hp). [/font][/font][/size][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,][size=small][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]On heavier grades, such as coming out of a river valley, it would downshift to 7th to maintain speed (2100 rpm/ 150 hp), but otherwise would stay in 8th. This is on relatively flat interstate of the Midwest. On open road without trailing a semi, we get a little over 30. At about 55 to 60 mph in heavy highway traffic entering a big city about 31.5 to 32 mpg...the other traffic helps pull and push you along due to drafting etc. [/font]

[font=verdana, geneva, lucida,]I've been hoping for a small diesel in a full size van for over 15 years. It provides the torque needed to get heavy loads moving, but sips fuel like a compact car.....a perfect combo for tradespeople. The big diesels never made any sense for regular tradesmen, since they don't almost never pull 15000 lb trailers, which I suspect is probably about 98% of the truck and van buyers. For that matter, must truck/van/ suv's are not carrying more than a couple of people, so it's about time a drive train was offered that fits this need quite well.[/font][/font][/size][/font][/size][/font][/size][/size][/font][/size]

[font=verdana, geneva, lucida,]This guy is a heavy driver - check out the cost returns...I don't know if he's figuring in higher maintenance costs - more oil, DEF but I assume that he is...[/font]

[font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]My only gripes have been the crappy factory shocks (this thing feels like our 2007 Jeep GC with 180,000 miles on it with the original struts) and the fact that the tranny holds low gears way too long. In city traffic this occurs about 35 MPH and it will hold the engine at about 2200 rpm until you accelerate to 37 mph, and on the highway....the trans will not upshift to high gear until 67 mph. On the highway it appears to be about a 10% hit in fuel economy at 65. In the city it’s a little harder to tell, but running 2200 rpm when you only need 1500 rpm or less can't be too good for economy. Again this is running about 7500 lb. GVW.[/font][/font][/size]

[font=verdana, geneva, lucida,]With the 20,000 miles per year we put on vans, the payback for the diesel upgrade is only about 18 months. If we keep the vehicle for 12 years (my daily driver is a 93), we should save about $30,000.00 on fuel costs over the 6.0 l v-8's that we have in other vans. The mileage is about double of the v-8s, maybe even more than double on the highway. [/font]

[font=verdana, geneva, lucida,]I do plan to complete some aero mods on the van that should bump the fuel economy up some more, since GM has done very little in this department and there's is a lot of room for improvement. I expect low to mid 30's mileage could be regularly attained with a loaded van, and maybe even better if running lighter.[/font]

[font=verdana, geneva, lucida,][size=small][font=verdana, geneva, lucida,]With the couple exceptions noted above… shocks, trans holding gears too long and poor aero… this is a really good combination. While mileage is still way behind full size service vans sold in Europe (they get about 40 to 45 mpg with 1.4 L turbo diesels), for a heavy full framed vehicle this is exceptional. We will be buying more of these to replace the 6.0l gas equipped vans we have in service. [/font][/font][/size]

[font=verdana, geneva, lucida,]Nice! [/font]

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It does seem a bit much doesn't it? We definitely need more data points. I had heard a 25% boost in MPG which would bring it to the low 20's on the hwy...

The longest and most informative post was from the Diesel place - not the EcoModder - from a commercial van driver apparently. 

I know most people think the MPG figures on the dash are inaccurate  but I checked that out and came to the conclusion that they are probably more accurate that attempting to do it on your own. 

What is your basis, though, for believing they are not designed for longevity?

 

[JD GUMBEE]

What is your basis, though, for believing they are not designed for longevity?

Millions of fleet units cradle-to-grave data at my fingertips...and knowing how the long-life engines are made.
Rebuilding engines and transmissions myself, knowing what lasts and what does not.
Talking to three of the GM master techs who are considered top of the heap (the ones they send a problem car to when GM is about to forced to buy it back under lemon law) about the value/issues/advantages of the engines.
Meeting with factory reps who, when asked about them, have said they were "okay for a baby truck." (Keep in mind they are trying to help sell their product.)

The turbo setup, the injection system and the emissions system are all loaded with electrics that fail.
Compared to an old mechanical B series Cummins, that engine is triple as complex and half as heavy duty.

I am not saying it's a BAD engine...but don't think it is going to live as long as the V8 Duramax.
Compared to the problematic diesels in the Ram vans and small Ram pickups, it may even be a better unit.
Make no mistake though, 2.8 liters is 170 cubic inches or so. That is the size of a Chevy Colorado engine. Not a one ton truck engine.

Too much truck on not enough engine=less life.

 

[cortttt]

Millions of fleet units cradle-to-grave data at my fingertips...and knowing how the long-life engines are made.
Rebuilding engines and transmissions myself, knowing what lasts and what does not.
Talking to three of the GM master techs who are considered top of the heap (the ones they send a problem car to when GM is about to forced to buy it back under lemon law) about the value/issues/advantages of the engines.
Meeting with factory reps who, when asked about them, have said they were "okay for a baby truck." (Keep in mind they are trying to help sell their product.)

The turbo setup, the injection system and the emissions system are all loaded with electrics that fail.
Compared to an old mechanical B series Cummins, that engine is triple as complex and half as heavy duty.

I am not saying it's a BAD engine...but don't think it is going to live as long as the V8 Duramax.
Compared to the problematic diesels in the Ram vans and small Ram pickups, it may even be a better unit.
Make no mistake though, 2.8 liters is 170 cubic inches or so. That is the size of a Chevy Colorado engine. Not a one ton truck engine.  

Too much truck on not enough engine=less life.

Good points. It is a VERY Complex engine. Amazingly complex really. I fully believe you're taking a chance with these new, very highly engineered and sophisticated engines. A lot more can go wrong for sure. Check this out on the new engine. The modifications are amazing. 
https://www.dieselworldmag.com/gm/first-look-gms-2-8l-duramax/
https://www.dieselworldmag.com/gm/first-look-gms-2-8l-duramax/

It does seem odd in a 1 ton as well. 

MPG is a big deal for me, though.......I would love to get better MPG.  Whether to chance it or not is a question I will have to deal with when the time comes. Hopefully we'll have more data by then. 

I know the 6.0 will go "forever"

 

[JD GUMBEE]

If you really want the ultimate longevity/reliability, spend the 12-15K installing a Cummins Reman 4B mechanical engine with a NV4500 behind it. (Cummins shops will do it...hang a clutch pedal and all.)

They will give you 22-24 on their best day...have more TQ than you will ever need...and last past half a million miles with good maintenance. Rock solid.
The 6B will deliver more balls, but 19MPG in my experience.
(And they will pull a house down, especially if you have a gov-spring and fuel rail mod done.)

It sounds crazy to sink that money into an old truck...but if you want true miniature tractor trailer (especially if you want to run grease as fuel) longevity/reliability. Set up right, you shut it by pulling a cable. No electrics needed to run these...not even a battery.

 

[JD GUMBEE]

...and sorry to 'reply' to my own post...but,

Having done three Cummins swaps personally and driven them a LOT, I can tell you the investment in time and $$$ did not come near making up the MPG difference. (Diesel is because you want it...not because the MPG increase pays for the difference.) Add to that diesel vs gas pricing in most states...and DEF (gag...DEF*ugh* cough cough) and that figure gets even more-not-worth-it.

Cummins makes a 2.8 diesel they use a lot for the Jeeps. Look up "TUBESOCK" on YT.
( Dirt Every Day...peace be upon them...Amen. )
If I was making the ultimate MPG half-ton nomad van, an elongated Chevy (Or a mint shape 1975-1991 Ford 1/2 ton) with a 6 speed Jeep trans.
(Not because its the toughest. Because it is adequate and would pass through more power than it vampires out. Many people do not realize that an L60 or 700R4 soaks up less HP than a L80 or Turbo400. Same with a C4 Ford vs a C6. The C6 never blows up, but you lose (most say) 25% more power through the C6. Meaning, more RWHP shows on the dyno slip when using a C4. Every single time. Hence, a light duty tranny from a Jeep/Chrysler (the company famous for beating the crap out of over rated wimpy components ever since the Kcar...) is one of the lowest power loss units available that little Cummins can mate up to.
The Cummins above would deliver excellent MPG and is a tiny bit simpler than the baby d-max (not too much really, but the turbo is more proven and simpler overall...and you can delete the freaking EGR/kitty-cat without penalty) (and no DEF) only...it isn't going to make 500K either.

Grease power changes everything if you have a free source, but those DI setups loaded with servo controls can be finicky about grease power. Anything but the proper fuel has been known to raise havoc. (Never seen it personally, but know many who have. GM will VOID your warranty for grease powering ANY of their vehicles. So will any other manufacturer AFAIK. Even Cummins.)

The old, mechanical Bosch pumps (non-electric B series 12 valve engines) are so tough, they will just about force solid butter through the injectors. LOL (Sir, your truck is making me think about baked potatoes... )

 

[cortttt]

Good points. It is a VERY Complex engine. Amazingly complex really. I fully believe you're taking a chance with these new, very highly engineered and sophisticated engines. A lot more can go wrong for sure. Check this out on the new engine. The modifications are amazing. 
https://www.dieselworldmag.com/gm/first-look-gms-2-8l-duramax/
https://www.dieselworldmag.com/gm/first-look-gms-2-8l-duramax/

It does seem odd in a 1 ton as well. 

MPG is a big deal for me, though.......I would love to get better MPG.  Whether to chance it or not is a question I will have to deal with when the time comes. Hopefully we'll have more data by then. 

I know the 6.0 will go "forever"

The ultimate engine modification...

 

[cortttt]

...and sorry to 'reply' to my own post...but,

Having done three Cummins swaps personally and driven them a LOT, I can tell you the investment in time and $$$ did not come near making up the MPG difference. (Diesel is because you want it...not because the MPG increase pays for the difference.) Add to that diesel vs gas pricing in most states...and DEF (gag...DEF*ugh* cough cough) and that figure gets even more-not-worth-it.

Cummins makes a 2.8 diesel they use a lot for the Jeeps. Look up "TUBESOCK" on YT.
( Dirt Every Day...peace be upon them...Amen. )
If I was making the ultimate MPG half-ton nomad van, an elongated Chevy (Or a mint shape 1975-1991 Ford 1/2 ton) with a 6 speed Jeep trans.
(Not because its the toughest. Because it is adequate and would pass through more power than it vampires out. Many people do not realize that an L60 or 700R4 soaks up less HP than a L80 or Turbo400. Same with a C4 Ford vs a C6. The C6 never blows up, but you lose (most say) 25% more power through the C6. Meaning, more RWHP shows on the dyno slip when using a C4. Every single time.  Hence, a light duty tranny from a Jeep/Chrysler (the company famous for beating the crap out of over rated wimpy components ever since the Kcar...) is one of the lowest power loss units available that little Cummins can mate up to.
The Cummins above would deliver excellent MPG and is a tiny bit simpler than the baby d-max (not too much really, but the turbo is more proven and simpler overall...and you can delete the freaking EGR/kitty-cat without penalty)  (and no DEF) only...it isn't going to make 500K either.

Grease power changes everything if you have a free source, but those DI setups loaded with servo controls can be finicky about grease power. Anything but the proper fuel has been known to raise havoc. (Never seen it personally, but know many who have. GM will VOID your warranty for grease powering ANY of their vehicles. So will any other manufacturer AFAIK. Even Cummins.)

The old, mechanical Bosch pumps (non-electric B series 12 valve engines) are so tough, they will just about force solid butter through the injectors. LOL (Sir, your truck is making me think about baked potatoes...  )

I have a masters degree in environmental sciences: for me the issue is not money but CO2 emissions. I would feel more comfortable driving a car that contributes less to global warming even if it costs more in the long run.

 

[JD GUMBEE]

Butter cant be bad for the environment
Tastes too good.
LOL