Originally Posted by BMWM.D.
I've installed a few sets of these new injectors. They are easily identified by their index number of "11". They are improved injectors that were mainly designed due to the problems BMW has been having with the N63 engines -- which seem to be more sensitive to injector tolerances. According to BMW, you can run either the new or old style in the N54, but you can't mix/match them on the same engine.
Maybe my source was incorrect, but I was told the old part number was currently on back-order and that the new number was the same price. I'm assuming the new, improved parts are going to be the only option as soon as everyone runs out of the older "261" part number.
Your source is correct. Same applied to my place. You cannot order the 261s. Basically if you have 261s in stock, they want the dealer to use those first. However they cannot be ordered. If you order a 261 the order gets cancelled and you get 079s. If its an N63 it MUST get 079s. If you are trying to install less then 6 injectors, it MUST get 6 new 079s, unless there are 261s available.
We have had many N54s in the shop in the past few weeks that needed 1 to 3 injectors. All of them had to get 6 079s because of zero availability on the 261s