You all could have a bit of a look at service intervals on every car ever produced in the last 50 years, I have yet to see one based purely on mileage - there is a time factor in there too, this is because various parts of the oil start losing their effectiveness when exposed to heat/air/contaminates, I think 6 months OR 3000 miles is more appropriate than a year - its not like its a huge $$ thing to protect your $howevermuch to replace motor
Who do you think came up with those oil change intervals? Scientists working in a lab for the good of mankind? Or was it oil companies/car manufacturers who make money every time you come in for an oil change?
