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.