06 Fuel Mileage

[Russknh]

I had a 05 SRW 3500 with the 6 speed trans and found the mileage to be lacking quite a bit from previous 03, has there been any improvement in either programming or engine design to make us think the 06 will be any better? I am afraid it is all going down the tube in 07 and think this is the time to buy one last truck for a while??

 

[tareynolds]

there is a controller software update for this issue, see your local dealership, this should be covered and it does improve your fuel milage.

 

[kernen]

]there is a controller software update for this issue, see your local dealership, this should be covered and it does improve your fuel milage. [/QUOTE]



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TaReynolds

Do you know what the update number is ; for example the 04. 5 HO had a flash it was 18-037-04 and it did improve fuel use some.

Thanks ,

Kernen

 

[fozzy]

My new 06 Mega Cab is getting around 16 mpg hand calc. (overhead shows 15). It is far from being broke in. My 03 milage has been the best of any of the 24 valve engines so far. It get in to the twentys pretty often. I have not seen that since the old twelve valves. My brother has a 05 and he has not seen anything above 18. Only time will tell for the new 06. It does run real strong and smooth, i'll give it that.

 

[BHolm]

I have had the same experience as fozzy. My '06 Mega, with 3000 miles on it is getting 15-16 right now which is a slight improvement from where it started out. My '05, once broken in, was getting 17-18 and my '03 HO was in the 20's all the time. More power requires more fuel. All of mine have been automatics. Since the '05 and '06 are mechanically identical I expect to get to 18 with it eventually.

 

[wcjp]

My 06' Mega w/3,800 miles just hit 17mpg hand calculated. The overhead console is consistently wrong by 2mpg. It was 15-16 until now.

 

[ohnoitsyu]

My 06 gets 14-15 (I've never seen 16 - ever!), and it has just under 5000 miles. Overhead is damned closed to hand calc. Overhead can not calculate coasting, so it seems, so when I do a lot of coasting, hand calc shows better.

 

[SThorud]

More power requires more fuel.

Not necessarily. Power required is a function of drag, weight and mechanical losses (rolling resistance, gearing losses, etc. ) Given the same efficiency between two motors, they will use the same amount of fuel at the same speed/rpm. The higher power motors just have the "potential" to build more power. If you use it, yeah you'll get less mileage but if you keep your foot out of it, it all comes down to the overall efficiency of the engine.



Why is a 400hp Corvette able to get 28-30mpg at 60mph? *rhetorical question*

 

[BHolm]

Not necessarily. Power required is a function of drag, weight and mechanical losses (rolling resistance, gearing losses, etc. ) Given the same efficiency between two motors, they will use the same amount of fuel at the same speed/rpm. The higher power motors just have the "potential" to build more power. If you use it, yeah you'll get less mileage but if you keep your foot out of it, it all comes down to the overall efficiency of the engine.



Why is a 400hp Corvette able to get 28-30mpg at 60mph? *rhetorical question*

But in this case, when we are all talking about pretty much the same trucks, with the same engines, transmissions, gearing etc etc etc, I am pretty sure my comment applies.



Driven exactly the same, on the same roads my 2003 got WAY better milage than either my '05 or '06 and I had the '03 and '05 at the same time and they were compared directly. The '03 would knock down 22mpg and the '05 would get 18. We are paying with milage to have more power, lower emissions and quieter trucks. No matter how much I keep my foot out of it, the Cummins "600" trucks simply do not get the same milage as the older 305/555 HO engine trucks.



In this case we are likely both wrong. I think the real reason for lower milage is the third injection event on the "600" engines.

 

[mberry]

But in this case, when we are all talking about pretty much the same trucks, with the same engines, transmissions, gearing etc etc etc, I am pretty sure my comment applies.



Driven exactly the same, on the same roads my 2003 got WAY better milage than either my '05 or '06 and I had the '03 and '05 at the same time and they were compared directly. The '03 would knock down 22mpg and the '05 would get 18. We are paying with milage to have more power, lower emissions and quieter trucks. No matter how much I keep my foot out of it, the Cummins "600" trucks simply do not get the same milage as the older 305/555 HO engine trucks.



In this case we are likely both wrong. I think the real reason for lower milage is the third injection event on the "600" engines.

I don't believe it has anything to do with the mechanics at all. I think it all resides in that silver box attached to the engine just like BHolm suggested. The programming for these engines has changed quite a lot and that is where the difference in mileage comes into play. Just my opinion of course.

 

[Trent]

Depending on which six speed you had, it could be a big difference. The OD gear in the newer G56 six speed is terrible and will hurt your mileage compared to the nv5600 six speed.

I had a 05 SRW 3500 with the 6 speed trans and found the mileage to be lacking quite a bit from previous 03, has there been any improvement in either programming or engine design to make us think the 06 will be any better? I am afraid it is all going down the tube in 07 and think this is the time to buy one last truck for a while??