Keep us posted on how it works. I have a 2005 Suburban that I would like to track mpg like this.
As an owner of a lot of full size vehicles over the years, trying to figure out how to drive them efficiently has always been top priority.
1. Slow down. You're punching a big hole in the air. Your biggest enemy at highway speeds is drag. 60-62MPH is usually the sweet spot.
2. Accelerate slowly, like if you were pulling a heavy trailer. You have enough power to haul heavy, but that doesn't mean you need to use it all the time.
3. Keep the tires inflated to correct specs. They don't always have to be at the max (especially LT tires), but somewhere between 75-90% depending on ride quality/wear.
4. Tune it up before the 100k mile service interval. I like 50k miles but I spin my own wrenches. Sure, they'll usually run ok until then, but not optimally.
5. Synthetics rarely gain noticeable increases in economy. They can increase the longevity of components though.
6. Disconnect "cold air" routing in the winter. Cold air is more dense, dense air requires more fuel. I picked up .5MPG in the winter on a Ford V10 van doing this. I put it back in the spring.
Much else and your break even point is going to be years in the future.
