Originally Posted by bimmerdiesel
It will be in service history. If OP is looking for # owners troubled by carbon build up then it will be beneficial to him. Curious why did you have to do it out of your pocket. IL doesnt come under emissions warranty?
It seems like you do lot of highway miles too so issue shouldnt occur in first place.
I'm way past the original 50k mile warranty, so when the carbon cleaning came up it wasn't a covered part or service for my 3rd party warranty.
I do over 90% highway. I drive about 850 miles a week of which ~800 is highway averaging around 67 mph. I use cruise control as much as possible so my lead foot doesn't get me in trouble. This keeps the RPMs at about 2k. If the manufacturer's recommendations told me that would cause carbon, I'd have adjusted my style. Better yet, if the car was designed for highway use, it would have adjusted RPMs accordingly.