Hello, I just recently had an oil analysis done on my oil with 8,000 miles on it. I am using Liqui Moly 5W40 Premium Synthoil. According to the results, I should be able to go 10K easily. I will attach the report showing you all the information. Hope this helps! It is from a 1997 C230 all stock. I went through Blackstone Laboratories to have the analysis done. Hope this help with your next oil purchase!!! I get it from either Napa or AutohausAZ and stick with a Mann Oil Filter.