Though a simple enough question, this is still a matter of some debate among service providers and BMW enthusiasts alike. BMWs are “engineered” to have 12,000 and up to 15,000 mile (or one year) oil change intervals. Exactly who engineered this extended service interval? Was it the engine designers or perhaps the accountants? Changing the engine oil sooner can only help prolong engine life and performance, granted it does cost more. Here in Dallas Ft. Worth under the extreme Texas summer sun, high heat and severe driving conditions put engine oils to the test. Engine oils in this hot environment …