Fuel Mileage

[Ed Wright]

A lot of guys with the '07 & '08 Duramax and Powerstrokes are crying. The particle filters, mostly their filter cleaning mode, kills mileage. They tell me they are getting gasoline-type mileage. 2006 appears to be the last good gas mileage Duramax. One friend traded a 200,000 mile 2000 Ford for a new Chevy and almost cut his mileage in half. He ain't happy. They make "off-road" pipes that replace all that, but that is illegal and your warantee goes out the window. Don't want to tune or "chip" one either. The '07 & '08 Duramax ECM stores a record of the last ten calibrations it has seen. Warantee work could include the dealer downloading that info for GM Powertrain to look at. Good by warantee. The only way to get around tuning one is to buy a new extra ECM for the tuning, and keep the orignal unmolested box to be reinstalled before it goes in for warantee work.

My '04 GM 8.1L gas motorhome will get about 9 or 9.5 if there is no wind (not many trips so far this year with no wind) and 65 mph. Buy some E10 gasoline and it gets about 7 to 7.5. Wind blows and E10, 5.8 to 6.2. At 75 mph, about 8 with straight gasoline and no wind. Tail wind? Ain't seen one yet this year. Running 75 mph, E10 in the tank and wind blowing, I don't even want to look. Got to thinking I should have bitten the bullet and bought a diesel pusher, until I talked to some guys that have them, and thier mileage is no better than mine. Their fuel also cost more.