Real world Chevrolet 6.0 gas mileage in 2500 HD

MossRoad · Sep 3, 2015

Yes, but it may shift into 2nd before you want it to.

Yes, you can start with it in M4, but as you said, it will start in 1st, and it will act exactly like it would as if it were in Drive, except, once it shifts into 4th automatically, it won't continue on to 5th.

In our car, I only use M (Its called L in the car) in hilly areas. I set it to 3 so that when I'm driving along in Drive and I hit some large downhills and don't want to heat my brakes up, I pull it into manual and let the engine brake me down the hill. I've found 4 is too high for most hills at 60mph in this particular car. But that's just my preference.

Anyhow, take it out and experiment. :thumbsup:

Copperhead · Sep 4, 2015

My 2500, if I move the lever to Manual Mode, it starts out in M1 and stays there until I up shift it. I generally just set the gear to top gear I want and let it do it's thing, unless I am really working the pickup, then I will go thru each one. My general use of M is on rural country roads. I want to keep it out of the top gear to avoid all the shifting and gear hunting on those hilly two lane roads. The driving speed on them is not high enough to really use the top gear effectively so it is shifting all over the place on every little mole hill. By keeping it out of the top gear, shifting is dramatically reduced. All that shifting is more detrimental to fuel economy than running a little higher RPM one gear lower.

And it is nice to drop gears manually as I am slowing down to avoid using so much brake and wearing them out sooner.

To dodge man's point, true, expecting a 3/4 or 1 ton to get 20 mpg towing is not going to happen, at least with the level of design we have. But it is realistic to expect those numbers if the pickup OEM's had kept pace with designs like the semi truck OEM's did. If modern semi trucks can get 30-50% better fuel economy, and sometimes even more, out of their diesels, compared to 15 years ago, pulling the same loads they have for the last 30 years, then it is not unreasonable to expect the diesel pickup OEM's to be capable of the same thing. It is unreasonable to expect them to actually do it, as they do not have the same motivation to do so as the heavy truck OEM's. That is why they have to be beat over the heads sometimes with CAFE stuff. The heavy truck OEM's delivered much improved fuel economy without any threat of CAFE stuff looming over their heads.

It is pretty sad that the pickup OEM's can't get engines to do better. While the heavy truck OEM's delivered better fuel economy, they also delivered more HP and more Torque to go along with it. The best the pickup OEM's can do is boost the power output. Heck, anyone can do that. Doesn't take a rocket scientist to boost HP and Torque. But is does take some candle power to do it while at the same time improving fuel economy by 50%. Sadly, the pickup OEM's lack any appreciable candle power.

buickanddeere · Sep 4, 2015

Semi's obtain thier mileage with efficiency of scale. If you really want to to see tons of freight per mile per gallon of fuel. Look at a diesel locomotive hauling 100 loaded freight cars.

rmk700 · Sep 4, 2015

MossRoad said:
Yes, but it may shift into 2nd before you want it to.

Yes, you can start with it in M4, but as you said, it will start in 1st, and it will act exactly like it would as if it were in Drive, except, once it shifts into 4th automatically, it won't continue on to 5th.

In our car, I only use M (Its called L in the car) in hilly areas. I set it to 3 so that when I'm driving along in Drive and I hit some large downhills and don't want to heat my brakes up, I pull it into manual and let the engine brake me down the hill. I've found 4 is too high for most hills at 60mph in this particular car. But that's just my preference.

Anyhow, take it out and experiment. :thumbsup:

Sounds like I do have some tranny testing out to do.

I do think your 1st gear theory is about as close as we'll get to the use it's for.

Lineman North Florida · Sep 4, 2015

Thank's to all of you who responded with gas mileage figures, I appreciate it. I thought I would give you an update on my mileage check for the week, all driving back and forth to work, so mostly stop and go, I checked it this afternoon and averaged 13.7 mpg. Charlie.

Gunny · Sep 5, 2015

If you're getting 13.7 in stop and go traffic, you're doing good, real good for a 3/4 ton

Copperhead · Sep 5, 2015

buickanddeere said:
Semi's obtain thier mileage with efficiency of scale. If you really want to to see tons of freight per mile per gallon of fuel. Look at a diesel locomotive hauling 100 loaded freight cars.

True, but even the ads on TV and on their website are not quite as they say. They take total tonnage and divide by fuel used to move it. Then they claim something like only needing 1 gallon of fuel to move 1 ton 480 miles or some such thing, as per the CSX Railroad website. I can do the same slight of hand calculations with my semi, and I have. Based on the very same method, I can move 1 ton 320 miles on one gallon of fuel. My truck gets 8+ mpg, and total gross is 40 tons. 8 times 40 is 320. So the rail fuel economy is indeed better at 480 miles per ton, but not as eye opening as many suppose. Works great for marketing the general public, but not so much with those that actually paid attention during math class. Ever wonder why they have 10,000 gallon fuel tanks strapped under those locomotives? it is not because they are fuel efficient.

Now we compare a average 2500HD, with a gas motor, weighing in at roughly 7200 lb with two people. That is 3.5 tons. at 14 mpg, that is 1 gallon of fuel to move 1 ton just over 50 miles. Now that is terrible. And the diesels are only, at best, 1 gallon to move 1 ton 100 miles. Still pretty lousy compared to semi trucks and trains. Again, my contention that the pickup OEM's have really dropped the ball stands validated.

buickanddeere · Sep 5, 2015

The difference between gas and diesel has narrowed considerably . When recent model direct injected gassers and ULS Tier IV diesels are compared.
There was the things were pre 1989, 1989 to 2006, 2006 to 2013 and 2015 & later. Comparing one era to another requires caution to avoid and apples to oranges comparison.

Copperhead · Sep 6, 2015

Can't speak to everything on the market, but the GM HD pickups have not improved much, if any, in the last 20 years for mpg. The GM HD pickups do not have DI motors and some of other stuff going on in the 1500 class pickups. I know many laud the new 6.2L Ecotec in the 1500 for it's power and mpg, but I am not sure the 6.2L would deliver that great of mpg if it was moving 1000+ lb more pickup like the 2500, that also has worse aerodynamics than the 1500 due to it's stance. I can pull off 17-18 for Hwy mpg with the 6.0 Vortec L96 in my 2015 2500, but I have seen no appreciable evidence that the 6.2L would do any better if it was moving the same 2500. And the 6.2L is locked into premium gas, where as the 6.0 can burn anything at the pump except diesel. I would much rather fill up with E85 that delivers 2 mpg lower than gas in my 2500 yet even with that, delivers 2 cents lower cost per mile than regular, than filling up with premium and not doing much better than regular. $1.84 for E85 in my area vs $2.63 for premium.

My '98 2500 with a 454 delivered me 16 mpg on highway. My 2015 2500 6.0L can only pull off 17.5 highway in comparison. Pretty sad. At least I can soften the fuel cost per mile by having flex fuel capability with the 6.0L.