I own a 2006 Chevrolet Silverado LT2 2500HD 2 wheel drive crew cab in Los Angeles. It has a 6.0 liter V-8 gas engine with a rear axle ratio of 4.10.
I bought it new in 2006 and have 28,900 miles on it. I currently average 9 miles to the gallon and on a great day maybe 11 miles per gallon. When I tow my 7000 pound trailer the mileage drops even further. It is a stock vehicle with only a K&N air filter replacing the stock one.
I need to know how to get more gas mileage out of this truck for less than $2,000.00?
You need to get rid of your idiot politicians or the idiot people who elected them! Based on their lack of knowledge and seeing the whole picture, your gasoline has been reformulated to be "cleaner" but it has come at a cost of reduced fuel mileage. If you fill up in a different state, you will find the mileage increases by around 20 percent. By the way, now they're finding ground water contamination from the reformulated fuel. So much for the brains of the politicians telling you what's good for you.
You also have a pretty high axle ratio adding to the problem. I realize this isn't a fix, but you might consider trading for a diesel truck. I helped a buddy haul a huge paint booth back from Houston, TX to Wisconsin with a Dodge dually diesel. We averaged, uh-hum, well over 65 mph most of the way home and the average fuel mileage was 22 mpg. Plus, we could pass anyone at will while dragging a huge construction equipment trailer. I suspect other brands would get similar results.
You can also try one of those "chips". That is a box that messes with some sensor values to increase power and mileage. I'm not sure if they make them for gas engines but I put one on a friend's two diesel trucks, again, Dodges. The first one had 150,000 miles on it. Within a month he tore the transmission out of it while pulling a three-place car hauler trailer. The second one is a '96 model with a manual transmission and dual rear wheels. He can slip the clutch if he tries due to the increase in power. Actually, from what I understand, diesel trucks are detuned at the factory below what the engines are capable of, so by adding these boxes, you are just bringing back some of the original capabilities. You can't hurt a Cummins diesel, but you will want to beef up the transmission to handle the power.