Im pritty sure the the 06 has a third injection event that hurts the mileage alittle!

 

How does the 06's 3rd injection differ from the 3rd injection in 04.5 and 05 trucks?

 

I just got back from a 412 mile trip on the interstate. There was a lot of traffic at times but was able to run 70 -75 most of the time. I used 22.8 gallons. Right at 18 mpg. I topped the tank right up to the neck both times. I now have 1k miles on the truck and am pretty content with the mpg. My overhead is only showing 16.5, but I always hand calculate about 1-2 mpg better than that. Tim

 

To the best of my knowledge all the 600's, 04.5 and up, have the third injection event. The poster specifically asked about the difference between an 05 NV5600 and what he would get in an 06 in respect to the mileage. As a rule, less mileage. Almost no difference in the fuel systems between the years.

I doubt if it does. And, if it does it is not very noticeable.

 

My new '06 G56 equiped 3500 SWB QC 4X4 keeps getting better and better mileage. First tank was about 15 mpg combined city/highway. On the fourth tank and on our trip from Reno to San Jose and back, about 530 miles, over Donner Summit twice, speed always over 70 and up to 80 mph. Some stop and go freeway traffic, I hand calculated 17.6 mpg. So far pretty happy.

 

My brother has about 500miles on his 06, quad, 4X4, 373's. He's getting 19.5mpg highway.

 

I'm getting better mileage w/ my 06 than I was w/ my 02 dually! I'm averaging about 16MPG right now (only have a little over 3700 miles on it). Best tank so far was 18.42 on a trip up north (mostly hwy).


Tony

 

Overhead console shows ~14-15, but hand calculations on three tankfuls so far show numbers in the 16's with the best one showing 16.75 MPG. Quite reasonable considering the engine only has 1500 miles so far. This isn't far off what I was getting in my Nissan Pathfinder, which weighed half as much and didn't have nearly the hauling/towing capacity.


Also, this is with winterized diesel fuel and low outside temperatures (meaning the engine runs less efficiently). I expect MPG's will bump up a bit as the weather warms up and they quit monkeying with the fuel additives.

BTW, I too agree the G56 transmission's 6th gear is too low. As you approach 75 MPH you're pretty close to the engine's redline. Seems like they could have geared it up a bit so the engine would be at its sweet spot of ~1800 when running at normal highway speeds of 60-70 MPH, but then again the 3500 is truly considered a WORK truck so they're probably thinking more about haul/tow optimization than highway cruising.