I change my filter at every oil change, and I change the oil (in the C280) at just about 3,000 miles if I'm using Dino oil. But if I'm using synthetic, I will go to about 4,500-5,200 miles (roughly) before a change.

I changed over to synthetic at about 100,000 miles and I didn't have any leaks. But my last oil change they used Dino because I took it in... What do you guys think of going back and forth?
(I'm sure it's totally fine.)

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)