Yesterday, I changed out the fuel injectors on the Karen-Mobile. The old injectors were of the 4-hole variety,and were likely the original injectors that have about 235K miles on them. The new ones were more of the 12-hole injectors of the type I already installed into my wife's Durango. Both have the same rated flow rate of 24.0 lbs/hr.
It's certainly possible that my old injectors were misbalanced and dirty to the point where they'd negatively impact fuel economy, so I am not ruling that out, but...
Normally, on my 19 mile drive into work, I would reliably get anywhere between 24.8 and 25.3 MPG. Nice, steady-state conditions (at least once I get out of the Cedar Rapids city limits, anyhow), little traffic, and weather conditions this time of year appear to be fairly steady.
I got 28.2 MPG this morning, with the new injectors. That's a 12.8% increase in fuel economy.
