I installed them in my 2017 DL 650 last year, at about 27,000mi/43,000km while doing other four-year maintenance. So far, no issues at all. After ~7,000mi/11,000km, I haven't noticed any performance or economy improvements (or losses), but I wanted the longer lasting iridiums. The OEMs were in good shape still. The CR8EIA-9s have the same reach and firing temp as the stockers.