I had oil change (synthetic 1st time) jun 2010 and now I havelow oil light on my dash borad. I took my car to mechanic who chnged oil and he told me that because my car has over 88000 miles so I have to use 10 w 40 oil instead I was using 10w 30 upto now. He said I need high mileage oil. My car burns low viscous oil. But I am not satisfied with his diagnosis. Any help will be appreciated. I am now thinking to sell my car.