6.0 gas engine

Doug Rosewood · September 3, 2017

In my head I understand partially, but I have to ask, why are there so many mpg threads in a forum section dedicated to fuel gobblers lol. You can't have a Prius and a truck capable of moving large amounts of mass unless you buy a train

SMiller · September 3, 2017

In my head I understand partially, but I have to ask, why are there so many mpg threads in a forum section dedicated to fuel gobblers lol. You can't have a Prius and a truck capable of moving large amounts of mass unless you buy a train

Couldn't agree more, let's debate the mileage of a 7,000lbs truck that has the exact same engine since '07.

News flash, the 6.0 gets 12mpg, end of all mileage threads forever...

4x4Pete · September 3, 2017

I wonder how much better fuel economy and power would be if one were to completely blueprint the whole drivetrain in a 2500HD gasser. The stacking of tolerances in the manufacturing industry can be excessive. This is why the exact same vehicles are so different. I think this has a bigger influence rather than what day of the week it was made. Either way the truck would still be hard on gas and power wouldn't be vastly different. It still would be interesting to see what the best case power and efficiency could be.

gearheadesw · September 28, 2017

Got 13 - 14 mpg with stock tires,

get 12 - 13 mpg with 325 65 18s with as little lift as I can get away with.

So a roughly 35 by 13.50 tire that weighs 70 lbs, only effected milage by... 8%, same as my delta number on the change in tire diameter from stock. Add 8% to my milage on the trip meter, divide gallons into miles driven. Semi close to real milage for truck.

TRKLGND · October 6, 2017

Couldn't agree more, let's debate the mileage of a 7,000lbs truck that has the exact same engine since '07.

News flash, the 6.0 gets 12mpg, end of all mileage threads forever...

I agree that they get what they get as far as mpg goes. However, the engine is not the only thing that determines mpg. I'm pretty sure that prior to '09 the HD's had the 4L80. I would think the 6L80 would help mpg but I haven't looked at the ratios of the two transmissions.

2016HD · October 8, 2017

Only way the 6l80/90 will help mph is in town. Lower 1st and 2on compared to 4l80. 4l80 first gear was way to tall for a towing rig. Other than that maybe very minor difference when it top gear. But not enough to compensate for the added weight of the newer chassis etc.

The variable cam timing should have helped some but only seems to have bumped the power a bit instead. I love the 6.0l and 6speed combo compared the older 4speed. Just wish they would have bumped the power to 400hp and 420/50 ftbls.

magnum74 · October 8, 2017

I love the 6.0l and 6speed combo compared the older 4speed. Just wish they would have bumped the power to 400hp and 420/50 ftbls.

Yup. I'm patiently waiting for info on the future gas HD. Will they massage the 6.0 or go with something entirely different? Unless I'm just looking in the wrong places there doesn't seem to be too much to talk about in this regard yet.

SierraHD17 · October 9, 2017

I agree that they get what they get as far as mpg goes. However, the engine is not the only thing that determines mpg. I'm pretty sure that prior to '09 the HD's had the 4L80. I would think the 6L80 would help mpg but I haven't looked at the ratios of the two transmissions.

4L80E ended with the gmt800 body in 2007. Anything 2007 onward starting with the gmt900 has been the 6L90E. The transmissions share absolutely nothing in common and the first gear in the 4L80E is almost exactly the second gear in the 6L90E. That alone was a nice change.. along with more gears, more efficient, deeper overdrive, etc.

Cowpie · October 30, 2017

I must have a very unique 2015 2500 6.0L If I average 12 mpg, it is on a very cold winter day bucking 20+ mph winds. Mine has averaged just shy of 14 mpg for the life of the truck. I can't recall ever getting 12 mpg or less on a tankful. On road trips, I have typically gotten 16+ most of the time. Even popped almost 18 mpg on a tank a couple of times. And yes, those were hand calculated mpg averages, not DIC. All told, it has averaged only 1-2 mpg lower than the 2013 1500 5.3 it replaced. And I have to be a little fair about it.... I don't really tow that much. Mostly got the 2500 for what I could load in the back, which is significantly more than a 1500 can safely deal with. A ton of building material or supplies in the back is not a pretty sight with a 1500.

GM is probably playing around with engine replacements for the 6.0L. Given that 3/4 of the 2500/3500 buyers are commercial users, they are not going to tick that crowd off and go goofy with some new engine that has a lot of wow factor, but could be more of a problem. The 6.0 has been a real reliable, rock solid engine for the majority of gasser truck users. Why mess with success? If one needs more power, the Dmax is always an option.

8lugCT · October 30, 2017

2 hours ago, Cowpie said:

I must have a very unique 2015 2500 6.0L If I average 12 mpg, it is on a very cold winter day bucking 20+ mph winds. Mine has averaged just shy of 14 mpg for the life of the truck. I can't recall ever getting 12 mpg or less on a tankful. On road trips, I have typically gotten 16+ most of the time. Even popped almost 18 mpg on a tank a couple of times. And yes, those were hand calculated mpg averages, not DIC. All told, it has averaged only 1-2 mpg lower than the 2013 1500 5.3 it replaced. And I have to be a little fair about it.... I don't really tow that much. Mostly got the 2500 for what I could load in the back, which is significantly more than a 1500 can safely deal with. A ton of building material or supplies in the back is not a pretty sight with a 1500.

GM is probably playing around with engine replacements for the 6.0L. Given that 3/4 of the 2500/3500 buyers are commercial users, they are not going to tick that crowd off and go goofy with some new engine that has a lot of wow factor, but could be more of a problem. The 6.0 has been a real reliable, rock solid engine for the majority of gasser truck users. Why mess with success? If one needs more power, the Dmax is always an option.

seems about what I would get if i didn't have 35in tires

TRKLGND · October 30, 2017

2 hours ago, Cowpie said:

I must have a very unique 2015 2500 6.0L If I average 12 mpg, it is on a very cold winter day bucking 20+ mph winds. Mine has averaged just shy of 14 mpg for the life of the truck. I can't recall ever getting 12 mpg or less on a tankful. On road trips, I have typically gotten 16+ most of the time. Even popped almost 18 mpg on a tank a couple of times. And yes, those were hand calculated mpg averages, not DIC. All told, it has averaged only 1-2 mpg lower than the 2013 1500 5.3 it replaced. And I have to be a little fair about it.... I don't really tow that much. Mostly got the 2500 for what I could load in the back, which is significantly more than a 1500 can safely deal with. A ton of building material or supplies in the back is not a pretty sight with a 1500.

GM is probably playing around with engine replacements for the 6.0L. Given that 3/4 of the 2500/3500 buyers are commercial users, they are not going to tick that crowd off and go goofy with some new engine that has a lot of wow factor, but could be more of a problem. The 6.0 has been a real reliable, rock solid engine for the majority of gasser truck users. Why mess with success? If one needs more power, the Dmax is always an option.

I only have 4800 miles on mine and I average 12.6 lifetime. Probably 25% highway and 75% city mostly unloaded. Only towed the boat twice so it was a non factor this season.

I have the Alaskan edition that has the Goodyear Duratrac tires. Probably cost me 1 mpg. Not worried about it. It gets what it gets. My '72 Sedan De'Ville with the 472 got 7mpg.

Cowpie · October 30, 2017

I have BFG KO2’s, next size up from stock.

SMiller · November 9, 2017

On 10/6/2017 at 12:00 PM, paracutin said:

I agree that they get what they get as far as mpg goes. However, the engine is not the only thing that determines mpg. I'm pretty sure that prior to '09 the HD's had the 4L80. I would think the 6L80 would help mpg but I haven't looked at the ratios of the two transmissions.

I have had about 20 6.0's, starting with 2000 model year up to 2015's, they all got 12mpg.

Yes the 6-speed low first gear is nice, not sure if the VVT 6.0 has the bottom end as it sure seems to have to rev higher not that I care.

A little tuning and 4.56 gears and I think it would be a winner.

Bhurt · January 6, 2018

On 10/30/2017 at 3:03 PM, paracutin said:

I only have 4800 miles on mine and I average 12.6 lifetime. Probably 25% highway and 75% city mostly unloaded. Only towed the boat twice so it was a non factor this season.

I have the Alaskan edition that has the Goodyear Duratrac tires. Probably cost me 1 mpg. Not worried about it. It gets what it gets. My '72 Sedan De'Ville with the 472 got 7mpg.

Also have the Alaskan, slight lift/level and otherwise stock. Just completed 3100 miles in 15 days through the rockies and back. Combination of highway and city and all kinds of weather. 19.5 works out to about 12mpg. If I wanted fuel mileage we could have taken my wifes dodge dart. But I wanted the convenience and safety of my truck on the highways.

AKNick · January 6, 2018

Been averaging 9.x MPG since I've had the truck. Only 600 miles on it now and I've got a few months to go until the summer when the summer fuel blend, no remote starting, and not running 750 lbs in the bed will help push that # up a bit.
Was getting 11-12 MPG with the Tundra I had before this with the same sort of driving. Similar load all the time too. But oh well. Needed the payload capacity of the 2500 and don't want two vehicles for regular use. MPG is not on my list of concerns, to be honest.