[JMB#7]

I have had a similar experience on a 2001 Jeep Grand Cherokee with the 4.0 liter inline 6 cylinder. In that case, the stock injectors were single hole, which I swapped out for Bosch 3rd Generation EV6 4 hole injectors of the same flow rate. Fuel economy did increase by about 1.5 mpg. But the bigger benefit was smoother idling, quicker starts, and better modulation of the automatic transmission. I also run the Autolite double platinum plugs APP985 and a K&N drop in filter with this set-up. (Please note that the filter & plugs had been in place prior to the injector swap) I do know that on some Jeep forums people will report an initial increase in fuel economy, but then it drops back closer to the previous mpg after the computer does a little "re-learning". In my case, it has sustained better economy. In general, more holes at the same flow rate will improve atomization at idle and partial throttle conditions. The peak horsepower or full throttle conditions will likely not change since there is plenty of turbulation under those conditions. I have also installed 4 hole injectors in a 1995 YJ Wrangler with the 2.5 liter 4 cylinder & manual transmission. There was not any appreciable fuel economy gain, but it started better, and ran much smoother throughout the full power band.