Should be no problems. I switched to 5W40 synthetic a hair after 300,000 miles. The only differences I noticed were very slightly better fuel economy and my minimal oil consumption went to no oil consumption.

Edit: Oh, and cold weather starting improved slightly. This was more of an issue in my 240D, which had loop glow plugs and was really past due for injectors.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.