Real world Chevrolet 6.0 gas mileage in 2500 HD

[dodge man]

I'll just point out one thing, when looking at fuel mileage that is pretty poor to start with, just a 2 mpg or 5 mpg jump is a big difference. Expecting a diesel 3/4 or 1 ton to get 20 mpg towing is not going to happen. Can it happen and has it happened, yes, just not on a regular basis. My truck has pulled down 15 mpg towing a car on a 7000 lb trailer and I was pretty thrilled it did that well.

 

[MossRoad]

Yep. Totally get the use of Manual mode. But why the 1st gear only option in addition to Manual mode?

Its the highest gear the vehicle will use while in manual mode. So if you want to go down hill it won't shift into 2nd unless you bump it up to 2, 3 for 3rd, etc... our 2013 Impala has it. But for some reason, no matter what you set it at, if you shut off the car, it always defaults to 4. I can't imaging a truck defaulting to 1. If you want to downshift while going down a hill you wouldn't want to go from say 6 in auto, to 1 just like that. I imagine there's overspeed protection etc... but can't find a good write-up for it.

 

[MossRoad]

M would allow you to select whatever top gear you want to limit to while 1 would strictly keep you in first. Does that make sense?

 

[downslope]

I had one, much older, a 1999, but I seemed to get about 12 loaded or empty. A 3/4 ton truck is designed to pull things, not be a commuter vehicle.

A 1999 gas would have either been a 5.7 or 7.4. I had a 2000 3500 SRW, reg cab, 4x4, 4.1 axles and that was still the old body style. It would get about 17 on the interstate empty and not pushing it. Pulling a medium sized trailer it would drop about 3-4 mpg, again not speeding. I currently have a 2008 6.0 configured the same but 6-speed auto and I find it to get about 2 mpg less than the 5.7, but with significant more power with the larger engine and 6-speed.

 

[C4Ranch]

M would allow you to select whatever top gear you want to limit to while 1 would strictly keep you in first. Does that make sense?

Totally makes sense. But why would you want to be locked into only 1st? Wouldn't M1 accomplish the same thing? Just trying to figure out why it's there.

 

[HHR]

A 1999 gas would have either been a 5.7 or 7.4. I had a 2000 3500 SRW, reg cab, 4x4, 4.1 axles and that was still the old body style. It would get about 17 on the interstate empty and not pushing it. Pulling a medium sized trailer it would drop about 3-4 mpg, again not speeding. I currently have a 2008 6.0 configured the same but 6-speed auto and I find it to get about 2 mpg less than the 5.7, but with significant more power with the larger engine and 6-speed.

The 6.0L came out in 1999 in the new body style 2500 series (8600 GVW) which was sold alongside the old body style 5.7/7.4/6.5 3/4 ton and up trucks until the NBS 2500HD and 3500 trucks were released for 2001. GM dropped the 3500 SRW model after the 2000 model year and it did not return until 2004.5 and was only available in long bed configurations.

 

[rmk700]

It sure would of been nice if GM would of put the -/+ shift buttons on back of steering wheel instead of the radio channel change buttons.

 

[MossRoad]

Totally makes sense. But why would you want to be locked into only 1st? Wouldn't M1 accomplish the same thing? Just trying to figure out why it's there.

Well, as I understand it, M can be set for any gear. So lets say its in 4 and you want to start out and stay in 1. If you put it in M and it was set to 4, you'd then have to bump it down three more times to get to 1, whereas if you just pulled it into 1 from the beginning, you'd be set to go.

I can think of many times I'd like to be locked into 1st, like pulling a boat out of the water. Going down a steep trail on our property, etc...

 

[MossRoad]

It sure would of been nice if GM would of put the -/+ shift buttons on back of steering wheel instead of the radio channel change buttons.

On our 2013 Impala the radio volume buttons are on the back of the right side of the steering wheel and the +/- gear change buttons are on the back of the left side of the steering wheel..... I HATE IT! It should be on the shifter where it belongs!

 

[rmk700]

Well, as I understand it, M can be set for any gear. So lets say its in 4 and you want to start out and stay in 1. If you put it in M and it was set to 4, you'd then have to bump it down three more times to get to 1, whereas if you just pulled it into 1 from the beginning, you'd be set to go.

I can think of many times I'd like to be locked into 1st, like pulling a boat out of the water. Going down a steep trail on our property, etc...

The only way you'd start in M4 is if you were at a 4th gear speed and move from drive to manual. So if your stopped and put it in manual it will be in M1 already.

I'll have to try it but I guess you could start (from a stop) in M4 by changing the +/- button to 4.