Home Forums Gear Hunting Trucks and Four-Wheel Drives 3.0 duramax

I’m seeing these videos of guys getting upwards of 30mpg on the new 3.0 duramax in the Silverado 1500.

Any first hand experience?

Thanks all

No experience here, but I'd appreciate input on the 3.0 as well.

It looked interesting to me until I saw the oil pump belt replacement at 150k. Have to pull transfer case and trans to get at it since it's in the back of the engine. Just my thoughts, otherwise I liked the idea.

I just don't see where pulling the trans and transfer case is that big of a deal. I'm sure a good mechanic could complete the job in short order. It reminds me of the truck "experts" who advise against a Super Duty because "they have to pull the cab to work on them". Removing the cab gives much easier access to work on the vehicle, and I believe there are only 8 bolts holding the cab to the frame on a crew cab Super Duty.

I have a 2020 Silverado with the 3.0 Duramax. About 12000 miles on it now. In mixed driving, I average about 23.5 mpg. My commute is about 250 miles per week of 75% highway and 25% city driving. On pure highway trips, it averages between 25-32 mpg, depending on wind, speed etc. I have larger than factory AT tires, so I imagine that will cut into mileage a bit as well. For my driving style, I really love the 3.0 Duramax. I don't have a heavy foot and I like it better than the 5.3 V-8 that I have had in the past.

Duckster, you have one heck of an engine. Almost full torque a 1600 rpms. No variable valve timing on a fkn v6 is going to produce that low end.

A long stroke inline six, where the stroke is longer than the bore diameter, that's a truck motor. With the inline 6, you have a piston firing off, every 60 degrees of crank rotation, rather than the 90 degrees of a v8.

I've never found an inline six motor I didn't like. The people who are prematurely crying about the oil pump belt, the motor just came out for Christ's sake. Give it a rest parrots

In the half ton world, hats off to gm for slapping the only firewood tractor motor in there......

Thanks for the info guys

Just keep in mind that based on the price differential of gas and diesel you need to get better mileage in a diesel to cover the fuel costs. In my area it’s about 15% more for diesel right now, and that gap is usually larger than that. DEF expense is typically fairly small, but some of the emissions related expenses associated with diesels can be pretty salty.

The 2011 Duramax 6.6 I had was a great truck, but I had to replace all the NOx sensors, the DEF tank, all the glow plugs, and it had a failed EGR cooler bypass valve. Plus, the DEF/computer shenanigans threatened to leave me on the side of the road in an artificially induced ‘limp mode’ several times. I was also at the end of expected life of the DPF, alone with the ever present threat of the $10,000 Bosch CP4 fuel pump failure.

Maybe they have all that garbage better sorted on the new ones, I don’t know. I also have no idea how the baby diesels are. I would say the new diesels are insanely powerful but more problematic than the diesels of old. I would say the new gassers are also insanely powerful and more reliable than the gassers of old. I guess you gotta pick what works for you.

Here's my 2020 Ram 1500 Laramie Crew 4x4, Ecodiesel, 3.92 rearend, from a recent turkey hunting trip.

So did you buy one?

Not yet HawkDriver,

I love and hate looking for a new truck. I’m looking at the trailboss custom if I could find one in 6.2, the 6.6 gas 2500 or the 3.0 duramax for the gas mileage. I guess we’re blessed to have these decisions

Mgunns

Pulling cases and transmissions are not very difficult. YOu do need the equipment such as lifts, supports, and jacks that make the job easy. You can have a transmission out of a 1/2 ton truck in 3 to 4 hours and if you servicing a high mileage truck, time to change out the rear seal at the time. No point fixing the truck, and still having an oil leak....

“We can use an internal belt that requires changing at 150k, or counter-rotating gears that’ll last forever. Which one should we do???”

“How much can dealers charge to disconnect drive shafts, drop the tranny/transfer case, and replace the belt/change the main seal/change the tranny fluid/replace the u-joints???”

“Oh, about $3k....”

“Put a belt in it!”

People panic about the dumbest [bleep], to worry about something that you’ll have to do in 150,000 miles is silly. I remember when my Toyota’s needed a timing belt every 60,000 miles to the tune of $600 a pop, didn’t steer anyone from owning them.

Geartrains are great for longevity but can pose problems for noise. Automotive manufacturers keep that in high consideration these days. Quiet engines, especially diesels are a priority for many applications. Using a belt is a simple solution.

Actually a much cheaper solution. I don't think noise is a consideration with a diesel engine in this instance. Timing belts became popular in the 70's and 80's because single and double row chains would "grow" as they got to operating temperature. This became an issue for emissions compliance. Timing belts offered more consistent valve timing regardless of temperature, until they broke. Current triplex type chains and variable valve timing makes this a non-issue, but are more expensive to manufacture.

I don't think anyone in this thread mentioned timing chains, as you posted. fburgtx mentioned gears, and I posted "geartrains". Not timing chains. Big difference.

I guarantee that noise is always a concern, especially for a passenger vehicle. Even industrial engines. Spark ignited and especially compression ignited.

Ok, not going to argue semantics here, but technically, "geartrains" refer to components that transmit rotating torque, as in a manual or automatic gearbox. Belts are not generally used in automotive applications for that purpose. The alternative to a belt on a crankshaft driven component, whether it be a valvetrain or an oil pump, would be a gear drive, direct drive, or a chain drive. So, me referring to a timing chain drive, instead of just a chain drive was not accurate. Still no question in my mind though, that the use of a belt in this case is cost driven, or a concession to a packaging problem, rather than anything else.

I've got a 1500 Silverado Z71 LTZ with the 3.0 Duramax. I bought it at the beginning of 2020 and have put 35,000 miles on it so far. Mileage has been great - I've averaged right around 27 for the whole time. If I'm driving steady highway miles at moderate speeds, I'll see around 30. At 80 mph or so on the interstate, it is around 25-27. Towing anything has a bigger effect on mileage than with the bigger diesels. I like the engine and the 10-speed tranny combo for my driving. Even with its relatively low hp numbers, the torque is good and its plenty fast.

The truck was problem free until about 33,000 miles. Then the anti-lock brakes and stability control system went out. The dealership replaced the computer control module for that system and I still had problems, so they ended up replacing the brake master cylinder. There was also a problem with the DEF system at the same time that was causing the truck to feel jerky at speed, at it was affecting the fueling. The dealership had to flash the computer control for the DEF system (this is all based on what they told me - its beyond my shade-tree mechanical ability). All was covered under warranty, but doesn't inspire confidence at this point.

Hopefully that will be the end of the issues. 2,000 miles later all seems fine.

We have a 3.0 Diramax and love the torque with the 10 speed transmission. We get 24-31mpg. We can haul 3 big round bales on a flatbed trailer and get about 22mpg.

That’s awesome mileage you all are getting with the 3.0

I have a 2.8 in a Colorado ZR2 and about the best I’ve seen is 25-26MPG in any of my driving.

I’d definitely take a look at the 1500 if it’s that much better.

Good luck truck shopping.

Whoa there , help me with the math...ok, 720 deg rotation in any 4 stroke eng divided by 6 cylinders....isn't that 120 degrees between firing strokes?

Nice engine as is the engine on the Ram.

Very interested in a 4x4 Crew cab 6.5 ft bed just want to know how it will do with short trips sitting all winter and DEF issues, and cold weather. Do not tow more than 6K and tired of 2004 Silverado 5.3 lack of torque.

I worry about that with my Colorado, but I mostly run it back and forth to work which is 100 miles round trip and up and down the freeway weekly. If it’s cold it’ll idle for a few minutes but I make a point of not letting it sit for long periods of time. Just about to turn a 100k on the truck so I don’t know if I’m right or wrong, but something is work.

Awesome little motors. I’m sure the 3.0 is even better.

I have a suburban on order with the 3.0. I'll be lucky to see it this year.

Bb

sounds like a GM vehicle

DEF has shorter shelf life in hot weather than winter

I’ve heard nothing but great things about their 3.0 Duramax in Tahoes and trucks. Mileage is better than my ZR2 with the 2.8 and way less emissions BS also. Not sure if the 3.0 system is more refined or whatever but I’d think that Suburban should be a great rig BB.

Getting over 25 MPG from a Suburban is good, no matter how you look at it.

Well to follow up... trucks were few and far between and I hear they still are. I bought a 2021 f150 5.0 and like it pretty well. Low to mid 20s might but great power. I would have bought a chevy 3.0 I think but absolutely none were in stock. Regardless, I'm happy with purchase so far

FYI, next door neighbor owns a Diesel truck repair center, with many years of experience, and he works on all of the brands. He just purchased a 6.2 gas and will not buy any of the late model diesel engines due to the extreme cost of repairs and lack of parts. He says the EPA regulations have eliminated any advantage diesel had over gas and they are only worth it if you have the need for the torque for extreme towing. Just another opinion.

Your neighbor is a smart man. People are dumping diesel rigs out here like crazy. 10-12k premium. Astronomical repair and maintenance and the fuel is higher. 99% of people who think they need one DONT.

My diesel mechanic dumped his for a 3/4 ton gasser. When the guy that works on them and can basically do the work for the price of parts says ‘forget this, give me a gasser’ you know it’s getting bad.

I have put about 50,000 miles total now on two different Silverado 3.0 diesel trucks. No issues with the motors or with the trucks themselves. I would agree with what other posters have said regarding mileage. 60-65 mph and minimal wind - will generally get 28-30 mpg. Faster or more windy, more like 25-26. I average about 24.5 mpg per tank with my mix of commuting/daily driving. I drive about 60 miles per day for work/personal use and that is probably about 70% highway/30% city. Very quiet and smooth motor and the 10 speed tranny works great with the 3.0 motor. Not a rocket off the line but plenty of pickup once it is in motion. Have a new Trail Boss with the 3.0 on order but it probably won't be here for another 6 months or so.

Just a quick update. Had to tow a 6x6 deer blind out to the ranch on a 16 foot tandem axle trailer. Got an average of 17.4 mpg for the entire 450 mile trip. Not a real heavy load but given the size/shape, it did catch a lot of wind. 65 mph highway driving.

That’s pretty damn good I’d say. My Ram 3500 won’t get 17 going down hill with a tailwind.

Traded my 2020 Ram Ecodiesel for a GMC Sierra SLT with the 3.0 Duramax. Admittedly this was on level ground with a 15mph tailwind, but nevertheless I was impressed. It's a very smooth riding and running machine.

I was curious about numbers on this 3.0 duramax and hadn't seen any posted here.

277 hp
460 lb-ft torque

For 2023 the 3.0L Duramax has been revised.

The new GM turbocharged 3.0L I6 LZ0 diesel Duramax engine replaces the turbocharged 3.0L I6 LM2 diesel Duramax engine offered for the 2022 model year. The new engine is rated at 305 horsepower and 495 pound-feet of torque, a 10-percent increase in power and a 7.6-percent increase in torque compared to the 277 horsepower and 460 pound-feet of torque produced by the turbocharged 3.0L I6 LM2 diesel Duramax engine offered previously.

Click Here

JG why’d you swap? Problems with the Ecodiesel or just time to trade.

32 MPGs in a full-size wouldn’t stink a bit!

What about all the electronics?

Amen! I’m really excited to see Rams new twin turbo inline 6 gas engine. I see huge potential for longevity and reliability if done right

I had 43,600 miles on the Ram, and started getting error codes for "service ESC system, Service trailer brake system, and service 4wd system". Was getting these even when no trailer was hooked up and in spite of the fact that the 4wd system worked exactly as it should in all modes. Took it to the dealer and they cleared out the codes, but they returned on my way home. Figured out I could start the vehicle in "auto 4wd" mode and the errors wouldn't appear except for the "service 4wd" code that would intermittently go on and off, but the other two wouldn't show up at all, which was good because when those showed up the cruise wouldn't work. Anyway, to make a long story short, took it back to the dealer, they think it needs a new ABS module, which would take 3 months to source the part. The dealer where I traded it off was also a Ram dealer and they said they would deal with Mopar on it, so I got rid of it.

Sounds interesting Drum! Hope you're doing well buddy.

I am getting a bit of the same deal. My 2020 is in for it's 2nd complete fuel system replacement right now. Over 2 months. I have been raising hell with FCA and the dealer but between the parts backup and all of the other horseshit, I am tired of waiting on stuff. It is a few months too old for a buyback. I was given a 1500 loaner, but that doesn't help move my gooseneck and 5th wheel trailers.

Sounds like it worked out great for you JG.

Friend bought a brand new gmc 1 ton with diesel few months ago. About 2 weeks later in the shop I forget what was wrong but it wasn’t a 1 day fix. They ended having that truck for over a month waiting on parts. My other bud bough a new f350 last year. Paperwork all signed he didn’t even make it off the lot if I remember right. It was a computer chip something I will have ask him when I see him. Sat at ford for a few weeks. They did give him a nice f150 for a loaner truck. GMC didn’t give my buddy chit.

John, it’s a complete ball buster. Mines a new 2020, but since it was over 18 months from time of purchase it doesn’t qualify for lemon law buy back.

Today, I’m seriously getting the Ford 7.3 gasser.

I traded mine as well JG , I was getting 22-23 HWY with the 5.7HemiHybrid. I just needed something for my wife and I barely drove it 6500 miles in one year . I am going to look at another Truck but have not decided on one yet. I have met exactly one person that has a 3.0 duramax and he was ecstatic with it.

Looks like it'll all be electric trucks soon. Putting dual exhaust on my 5.0 f150 hopefully this weekend

Talked to my nephew in Oregon logging country and some loggers are using the 3.0 GM diesel in their crummies will be interesting how they hold up.

Now over 60k in the 3.0 Duramax. I did have a check engine light that turned out to be the need to replace one of the sensors in the exhaust system. Other than that which was under warranty, no issues

Good stuff. Thanks for the update!

Duckster, thats better than a toyota Tacoma I bought few years back:

Long before 60k miles:
Front differential disconnect inop lost 4wd
Rear axle seal

Great engine in that truck. I'm building a gm inline 6 right now: 292 chevy.

Forged .060 high compression pistons, roller cam, roller rockers, clifford headers, clifford intake manifold. Davis Unified Ignition (HEI)

That 292 sounds like it'll be a good motor Mainer. What are you putting it in?

Beretz, developed a bad oil leak in my 2002 7.3 powerstroke. So just putting together a simple/cheap gas truck till I get that 7.3 pulled and overhauled.

292 is going in a 1968 k20 along with 4:56 geared axles and hydroboost brakes from a military m1028 suarebody with 13000 miles. Axles have detroit locker in rear, limited slip diff in front. 1 and 1/4 ton leaf springs.

That old K20 should be a beast! Maybe not friendly on gas but man, if you can keep it fed you should be able to get about anywhere you’ve got business taking a truck.

I just bought one last Oct new, now have about 10,700 mile. Love it so far and after much research, it’s what I was looking for.
Around town average driving get about 23 mpg, on trips including running around when i get there usually 26 mpg average. That’s numbers from the computer.
It also shows best mileage over 50 miles. 31.2. I have averaged 29 for interstate trips.

Very happy

My average for 75% highway and 25% city has been pretty steady at 24.5 mpg. That is with larger than factory AT tires

Have a 2022 Trail Boss with 15k miles and have averaged 21 since new. Not what I was expecting and definitely not worth the extra cost of diesel and DEF.

Good to hear. What kind of mpg have you been getting.

Sorry, had not checked back in awhile. I generally get 24.5 mpg on my commute/daily drive. I drive 56 miles daily for my commute which is 80% highway and 20% in town. It will do 28-30 mpg on the highway 60 mph. About 24 mpg at 70 mph. Depends on how much wind there is out there on the highway.

My current 3.0 Duramax is the Trail Boss version. Only 3200 miles so far but have been averaging the same 24-24.5 mpg as I did with the RST versions.

How are the 3.0 Duramax and the truck holding up, issues, waiting to buy one inventory is building and rumor that prices will drop.

hopefully the 3.0 is better than general motors transmissions

I have put about 65k on 3 different Duramax trucks. Only issue was a exhaust sensor at 32k that was replaced under warranty. No transmission issues

Very impressed with the low-end torque coming out of those 3.0's

Over 400 ft lbs at the wheels. Must be one towing son of a gun-half-ton.

I don't tow a lot, the heaviest is a 16 ft. open tandem axle trailer with fencing materials and such. Or a couple of UTV. No problems towing those items