I purchased a Sept 09 reg BMW 320i in March this year with only 1800 miles on the clock which would suggest that it had done mostly short journeys. It is now 12 months old and showing 7,500mls which have been mostly descent lengthy journeys. It is not due a service till next September when it will probably have covered only 17,000mls. Is it worth having an interim oil change now even though it is a petrol engine with no turbo? Being a pensioner I hope to keep this car for 7 or 8 yrs.