Klinquist, what is your around town mileage? I'm okay with my hwy miles but was looking to bump up the city mpg.

I've found that brisk acceleration is good for fuel economy in my van (07 V10 w/ 5speed automatic).

Think about it: it's "miles per gallon". If you accelerate slowly, you are not gaining as many miles but you are still sipping gallons. Obviously it's a ratio that is a delicate balance.

If it takes you 15 seconds to attain 45mph but I do it in 10... That's 5 seconds where I'm cruising at higher MPG and you're still burning more fuel to gently get up to speed.

Besides all that; I improve my mpg by coasting as much as possible, keeping speeds about 5mph under posted limits, and (trying to) minimize idling.

But even aside from all that: going from 10mpg to 12mpg- it doesn't add up. It's not worth your time. You said your wife drives 600miles a month. I drive that much in 2-3 days. The difference is $20/month for you based on $2/gallon fuel prices.

11-12ish. I don't think you can do much around the city.

Was that with a tuner?

I've got the 5star tuner, but I didn't see a big change in fuel economy either way.

When I had the 3.73 rear diff running in my '12 V10 E-350, i seemed to recall getting 11.7 or so in the city.

I put in a 4.30 LSD and Mike's 5-Star tuning, and basically am getting about 1/2 mile per gallon less than before. (My original programming had the tire diameter a little off, which led to perceived improved fuel economy, but once I realized it and re-programmed that parameter, the computer showed about 11.2 on avg).

I would recommend the 5-Star for the trans shift improvements and improved acceleration at highway speeds. Of course, the 92-octane program Mike gave me makes the van even more frisky when I'm running premium.

Bill,

With your current setup 10 city and 14.5 highway is pretty strong. With the tune you may see up to 1 mpg increase. Some see more, some see less. Even within the shop we each see a good bit of difference between our mpg increases. We all drive quite differently. The drivability changes will be the main reason to tune the van. Any economy increase on the 6.8L is a bonus.

Little radio. With the 4.30 gears your getting 11 in town or avg? What are you getting expressway?

Mike, I'm planning on getting the tune. It will probably be Christmas time. We took our 7k trailer up to boone nc and it kept dropping out of overdrive on the smaller hills. I would like to stop that and they tell me that I'd what your tuner will do. Right?

I avg about 13'ish mpg on long freeway rides. Drops to 9 mpg pulling a 10k lb box trailer at 65 MPH.