I have a '94 F250/460, I had a guy tell me that the gray colored injectors I have are the highest pressure Ford used for that engine. I read where the grays are 50 psi, I know nothing about it though. I only get about 7 mpg/3.55 gears/33" tires/3sp auto. I am going to switch to 4.10 axles to help my towing power, I know the mpg may not improve but was wondering if I could go to lower psi injectors without hurting the power much?

 

The injectors are rated in pounds of flow per hour at 3 bar, or 43 psi. The blue tops (should be what's in your truck) are 24 lb/hr. The engine computer is tuned for those injectors, which are sized with the fuel requirement of that engine in mind. The engine will require the same amount of fuel regardless of the injector size, so the small injectors won't be able to keep up, likely causing a lean condition depending on how much smaller they are. Stick with what you have, there's nothing to be gained fuel mileage-wise with smaller injectors.

 

OK, thanks E.