my truck is still at the factory 12.5 degrees, maybe valve adjustment and timing to 15.5 or 16? i would think a rclb 12v 5 speed could do better than 12.9 mpg. it sputters and white smokes off a free rev sometimes so im thinking that could be due to timing too? also did not mean to derail the OPs thread, but were kinda lookin for the same answers haha

Worn injectors can make a truck get bad mileage

I wonder what the life span is on an average set of 12V injectors. Mine aren't exactly new anymore.

at 294K it couldnt hurt to get pop tested i guess

next time you fill up ... put in a quart of dextron 3 atf ... then fill tank .. by the end of the tank your milage wil be better .. maybe not perfect but will be better... the detergents will help clean all the carbon off the injector tips.... i personally gained around 2 mpg's ... my buddys 24v gained 4 mpg and that was loaded with a 8k trailer.

any danger in doing this?

i took mine out at 240k and they were extremely dirty

I replaced my injectors 2 years ago. still havent had a chance to have my timing bumped yet but im getting there. im hoping maybe in the next couple weeks. there is a well known diesel shop not far from me that said he would do it for 150 bucks. im gonna go ahead and have him check out the kdp while he is right there. i will let everyone know my results when i figure them all out. thanks for all the input guys it really helps.