What kind of fuel ecomomy is everybody getting?

[mcedillojr]

I have a 2007 Chevy Duramax LLM and I get around 16.5 in town I only have 6500 miles and don't know if this is going to get any better. A few weeks ago I took a road trip to Dallas, TX form El Paso, TX. I left at night and the speed limit at night is 65 mph and my fuel mileage jumped to almost 22 mpg which was really awsome, but on the way back from Dallas I traveled during the day and the speed limit is 80 mph and my ecomomy dropped to 18.5 mpg. I knew that there would be a diffrence but I didn't know I would be this much. What kind of ecomomy are you getting?

[ssgreg@comcast.net]

With winter blend fuel here in MI only 14 in the city, summer I get 17 - 18

[Analyst]

I averaged 16.82 mpg overall from 33k to my current 106k miles. City seems to be 14-15. Highway ranges 16.8 to 18.75 with a rough average between 17 and 17.5 mpg when you combine winter and summer fuel blends, and that's nearly all 2-lane with very light traffic. On a divided 4-lane with medium to heavy traffic moving nicely, highway average will kick up another 1 to 2 mpg. I use Amsoil Diesel Fuel Modifier and Cetane Boost, so my whole system is very clean. When I bought the truck with 33k miles on it, I think it picked up 1 mpg just from the fuel additives - it seemed to be running 13-16 mpg before going to all AMSOIL.

Note that there are many factors that make up fuel economy. I couldn't find a good free online source, so I researched and wrote my own guide to increasing fuel economy (http://www.ultimatesyntheticoil.com/Improve_Fuel_Economy/Increase_Fuel_Economy.htm). Let me know if you guys have any thoughts or suggestions on improving the content!

I admit I do envy all you guys with the 2006 Duramax trucks, because they've got the best of all worlds: most advanced engine & turbo setup and 6-speed Allison, giving the best fuel economy and most power, without all the penalties of the DPF's. I hear they average 19-22 hwy? I had seriously looked at trading mine in on a new '06, but how do you justify $100/mo more in payments when the '02 is perfectly fine?