I read the posts and have seen most people do a ML oil change every 10,000 miles but there is no alternate mention of time i.e. 10,000 miles or 12 months? I bought my 2000 ML used with a fresh oil change and 36,000 miles on it. 7 months later I have 39,000 miles on it. That's about 4700 miles a year of weekend driving - half local, half highway. The FFS reads 4800 miles to go. So as you can see my driving habits suggest my oil chages be based upon time rather then mileage. Should I go by the FFS or change the oil every nn months? Suggestions

Thanks