I just wanted to get some educated opinions on the kind of oil I should be putting into my 1997 528i. I am a very amateur do it yourselfer, although I've done a few things now, including changing out my rear brake pads/rotors.. So, this weekend, it was time for my first oil change on my 97 BMW 528i that I got last October. I've put about 3800 miles on it and it now has 89,000 miles. So, when I check with my Bentley's manual, it says to put 15w-40 oil. I also checked the prior service records with the dealer and I found that this car has never had synthetic oil in it. So, I figure I will just stick with the regular stuff. I head out to the auto parts store and lo and behold, there is no 15w-40 on the shelf. I ask at the counter and they tell me its not very popular and they don't keep in in the store aisles. But, they did have it in stock in the back of the store and I do end up getting 7 quarts of Penzoil 15w-40. THey tell me its a very 'heavy duty' oil.
So, I go ahead and change my oil. But, now I"m getting second thoughts. Is this the right oil? Do I have anything to worry about? My engine and car is in excellent shape. Doesn't burn a drop as far as I can tell. Should I switch to Synthetic? Or, should I be using a different weight such as 20w-50?
Any feedback on this would be most appreciated!