Brucero,
I do run Mobil 0W-40 and the original oil filter which if bought at NAPA is the one for the SRT. I change it every 5000 miles. I was sitting at an airport a few months ago and spoke with a mercedes mechanic who said something about the mercedes engine in the crossfire having the same problems as the clk 320 engine with cracking of oil lines to the lifters but I haven't been able to find engine diagrams for this engine. I did run sea foam in the engine oil 1.5 ounces for each quart of oil and the ticking went down dramatically. The sea foam tech's said it's compatible with all engine oils and that they recomend running it all year round since it absorbes water due to condensation in colder temperatures. It's not an additive since it's an oil distillate. It does remove all varnish and absorbes water due to hot engines becomming cold especially in winter conditions. I own a 2005 limited roadster with 82000 miles. It's my daily driver.

Thanx for your response,

In Crossfire Brotherhood