I'm getting ready to have my thermostats and glow plugs/module replaced. In the winter, it runs at 79C and greater. In the warmer months, 82C and higher. I average over 26 mpg in mixed driving and +/- 30 if I stay on the highway. The 'temperature implausibility' DTC has been set twice over the last year/10k miles.

There is currently a DTC set for glow plug 6 and control and there is some smoke on startup. Oil analysis every 6000 to 7500 miles using Mobil 1 ESP Formula 5W30 and OE filters. The last oil change I went 9000 miles to evaluate the longer intervals. Today I changed the oil with Liqui Moly Top Tec 4605 5W30.

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8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim