RepairPal is your advocate for car care advice and guidance

Q: Gas mileage drop after new fuel pump installed. on 1998 Dodge Ram 1500

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
My fuel pump decided to stop working one night. Apparently, the electric pumps work well until they quit (unlike the old mechanical pump that would get weak but rarely completely fail, so you could limp home). Any way, I buy a new Bosch unit, and put it in. From that moment on, the gas mileage has dropped. And curiously, the FASTER I drive, the better mileage I get. As in 85 MPH gets me 17 MPG, but 70 MPH gets me 15, which makes no sense . . . unless the same volume of fuel is being pumped through the system regardless of my driving activity. My in-town mileage is around 11. Is this something anyone has experienced? Any one have any suggestions as to what the problem might be? And yes, I know the ultimate solution is to simply drive 85 MPH all the time, but let's pretend that option isn't practical.
No car image 94a1663db56199c5353592009e34aaa51078a2469bed068bb8d6f0ba43accf97
Get a Repair Estimate
Guaranteed by certified locations nationwide. Learn more
RepairPal estimates are guaranteed at over 1,700 quality certified locations nationwide. Learn more
Didn't find what you were looking for?