Well I need to change out my vp44 and lift pump but i was thinking about changing out my injectors at the same time. I found some bosch replacements for about 60.00 bucks and 300 hp injectors for 300.00 bucks So I was thinking of getting the 300 hp ones but i was wondering how much that would affect my gas (sorry fuel) mileage. My truck is not a dailly drive it gets driven maybe twice a month in the winter but once racing season starts i pull a enclosed car hauler weekly so is the mileage even somthing to worry about.

 

Your mileage will definitely suffer, but more so, your EGT's will skyrocket if you don't upgrade the turbo with those injectors. Diesel fuel without boost = heat. You gotta figure that for each pound of boost, you can cool your EGT's by about 10*.

I know on the stock settings, I push up around 1100* loaded and pushing it. If I push it to level 3/5, I can bounce it off my EGT limiter pretty easy and that is only pushing an extra 70hp / 150tq.

Besides, you'll be pulling more fuel than that VP44 can push and defintely more than your tranny can handle.