on my volvo with a more exposed filter,it toke me 4 hours on a cold day and i ended up smelling like gasoline despite washing up.
So i paid 80 bucks US to have it changed at a MB dealer's quicklube place,parts and labour combined.only takes 30-45 minutes on a hoist inside temp work.
This is one area the labor is worth it.esp at a discounted MB place.

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Tom 2010 C250 4-matic Sport (Canada)