I probably would be shouted at for writing this. I think people are paranoid. I mix it all the time, w10-30, w5-40 etc to my gas cars and diesel cars and it never gives me problem. If the car is a precision instrument like a watch then I probably would not do it. But MBZ engine is built tough and can take abuse within reasons. It may shorten the engine life by 1k miles out of 500K, I would still be very happy with 499K.

One thing I never short changed myself is the interval. I always change the oil between 3k-4k miles.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.