Injector #11 from #12, etc.

[vics]

Gang;

2013 X5M with 60K miles (CB with black). Did plugs tonight and was amused to see and swap out 'M' coded variants. I went for the $7 plugs .
Plugs took 50 minutes FYI for a 1st timer...Though having performed this often on an E39 M5 over the course of 300,000 miles, I had some familiarity.

Anyhoo - evident difference in performance post replacement so yes, 30K changes appear to be real. Nonetheless, also observed injectors are #11 (opposed to 12 or 13 or whatever's been produced since 2013).

The question: As the plugs look great, the car runs great, what might I gain if considering upping to a 12 or higher?
- Can someone definitively state that a 12 over an 11 is mandatory or an improvement?
- Why was 11 superseded by 12?
- Is there a #13?

Much appreciated.
Vic

[Thecastle]

The lower index injectors had a habit of failing. There was a recall on x5m to replace older injectors with index 10 or older. There would be a silver circle on the door frame of the drivers door if this has been done. The SIB 13 08 15 specified replacement if your injectors were index 10 or lower. To my knowledge there is no performance benefit to 12s just reliability.

My N63tu 550i has index 12, and my x5m s63 has index 12 and no failures yet.

I don’t know if there is a 13, but I haven’t heard of one. That would indicate the index 12s were a good design. Since they’ve been around for several years.

[vics]

Thank you! Great info. Have read up and will determine with SA (whoever that might be) whether my 4/2013 build is eligible for #12 or not.

Anyone capable of recommending a SA for Herb Chambers BMW in the Boston area?

Originally Posted by Thecastle

The lower index injectors had a habit of failing. There was a recall on x5m to replace older injectors with index 10 or older. There would be a silver circle on the door frame of the drivers door if this has been done. The SIB 13 08 15 specified replacement if your injectors were index 10 or lower. To my knowledge there is no performance benefit to 12s just reliability.

My N63tu 550i has index 12, and my x5m s63 has index 12 and no failures yet.

I don’t know if there is a 13, but I haven’t heard of one. That would indicate the index 12s were a good design. Since they’ve been around for several years.

[aligoodn]

I replaced mine last year with the latest part number available, index 12's is what I got when I ordered those. I'm not aware of a index 13.