I purchase my truck back in January 2008 and have loved ever since. Within the last three months or so and have seen a huge decrease in fuel mileage. Originally I was getting 16 around town and 22 hwy and now don’t seem to budge much above 13. Currently there is just over 58,000 on it. This is the first issue I have had outside of some emission trouble when it hit the 20,000 mark (consistent check engine light, soot in the turbo, and clogged DPF, etc). All were covered under warrantee and they cleaned turbo, and replaced DPF. There have not been any other issues with check engine light or other on-board warnings since. Took it to the dealer last week and they contributed the decrease in fuel mileage to the excess fuel dumped into the exhaust stroke to be burned in the DPF. Has anyone else experience an issue like this? Any known fixes or modifications that will help?

Thanks,
Mike