New 08 Vortecmax 6.0 Gas Mileage

[c4cruiser]

My 3 month old 08 Silverado with the VortecMax 6.0L motor doesn't seem to be delivering reasonable gas mileage. I went to the dealer today to talk about a rough idle condition when cold and intermittantly after the motor gets to normal operating temps so I asked about the mileage I'm getting.

 

Right now, the DIC is showing just over 14 mpg on a tank of gas. This includes a mix of city arterials of 35-40 mph and some freeway use at 60MPH. I don't drive it hard, just normal type of driving. The dealer service tech said that because I only have 2600 miles on the truck, it's not what he considers to be "broken in" yet. I have noticed that the AFM keeps the truck in V4 mode for slighty longer periods compared to when it was brand new.

 

So at what point is the 6.0 gas motor considered to be "broken in" to where I can expect somewhat better fuel economy? My 99 Silverado with the 5.3 and 4.10 gears would deliver over 15 in the same in town driving and over 18 on long freeway trips.

[VMax2007]

Don't expect any noticeable difference with more miles. That is all

 

Nothing wrong with 14+ mixed with the 6.0 Vmax.

[onac255]

Yeah I don't think your going to get mileage like the 5.3 did.

[99silveradoz71]

Exactly. My 08 Vmax has 16k on it now and tends to average between 14-16mpg depending on what type of driving I'm doing on a given tank. I tend to drive dad's Lesabre during the week since he passed away, so the Silverado comes out to tow my trailer for taking care of the family's yards and on off days.

[Vmax225]

I get a consistant 16.5 mpg 50% mix city/highway. If i dont hit the gas as much ill get 17.5....but i also have a tune.

[gnet158]

Don't forget that everyone's using winter gas and that usually looses 1-2 mpg. Get a tune and or programmer for better mpg. I'm getting 14-15 mpg but that's in a ton of stop and go traffic.