Originally Posted By: SubieRubyRoo
Not bad at all! Weirdest thing I ever saw was on my stepson's 2000 F250 with the Powerstroke. The injection pressure sensor went bad and we disconnected it before about a 100 mile drive after filling it up. The console monitor showed nearly 37.5mpg and I was like no way... til we stopped and I filled the tank up to calculate mileage. It took just over 3 gallons and worked out to like 31.8mpg. The next day after replacing the sensor, mileage came back down to the 18-21mpg range like it usually gave.
The only thing I can figure is when the IPS goes bad, the system defaults to max pressure, so it must have improved atomization and burn, especially since it was light-throttle driving. Was cool even though it was a one-time fluke!
Diesel fuel is pretty foamy, and filling up from a not empty tank probably triggered the pump to kick off early.