I could use some help guys! I just recently changed out my stock injectors to the rv275s and I lost a good chunk of mpgs, I was getting about 16.5-18 highway at 75-80 mph but now I’m down to 11-13 highway at the same speed. I have tried two tanks of fuel and gone easy on the pedal and tried to do 70-75 but still no increase in mpg. While is was doing the injectors I also added an aftermarket air plenum to help with the egts and trying to keep them down. I have about 140k on the truck so I did the injector upgrade. I also did a brand new fuel filter at the time as well. (It was time for oil, fuel, tranny filters and changes anyway) I have an airtex 3157 or something like that lift pump, in tank pump that’s stock, big line kit from filter to VP, fuel pressure gauge and its steady at 17-19 psi at idle. I’ve got an Edge EZ tuner (which is why the rv275s) heard it was a great powerful yet good mileage truck for a daily. The truck has the following mods: S&B cold air intake and air horn, edger EZ tuner, big fuel line kit, airtex lift pump (have a fast ddrp just not installed as the airtex is still pumping 17-19 psi) air manifold plenum, timbo apps, noise isolater for torque converter, gauges for FP, EGT trans temp, 5 inch turbo back exhaust, deep tranny pan +4 quarts more than stock,and the rv275s. Anyone know why I have dropped so much mpgs?

Also I made sure that I did the install properly I tightened down the injector last after the tubes and lines were all connected and tightened to torque as I was told that was super important to look at and not mess up. I’m just stumped as they came in a blue Bosch box and the part number was correct but I can’t figure out why I have lost that much mpgs. I could really use some input, do I get a bigger turbo? Go back to stock injectors? I really like the addition but the fuel price is hurting the pockets. Any help or advice is very welcomed!

 

The RV275s injectors could be consuming more fuel than your stock ones, which is impacting your MPG. The aftermarket air plenum and Edge EZ tuner might not be fully optimized for the new injectors, leading to inefficiencies. Try recalibrating the tuner for the RV275s, check the air-fuel ratio, and consider installing the Fast DDRP lift pump if you haven't yet. If you don’t see an improvement, reverting to stock injectors could help restore better MPG.