What do you mean 'always'?
Further, if youre saying synthetic is good for only 5k, then whats the point of synthetic oils to begin with! Also, my knowledge is that you judge whether an oil is in good shape or not by how the colour changes, how easily the car starts up and how efficiently it takes heat out of the engine. My friend with Shell running 14k+ says the colour has of course changed slightly (but not too much), the engine is starting and running excellently even at this stage with 14k (5 month) old oil and of course, the car is not heating up despite the terribly hot days we are having across the country. Hes in Lahore.
So if all of that is true, then why is there any reason to worry? I think 14k is pushing it, but 10k is good. Even at 10k, Ill be saving quite a bit, moreover based on what Im hearing, I shouldnt even have to worry should the oil change need a delay of a further 2-3k km, which is definitely not the case with standard oils as the 'danger zone' parameters are more restricted.
I have not used any synthetic oil myself yet and I am not a car or engine expert, but based on all of this, I think running the blue Shell oil for 10k km is quite reasonable. Of course Ill need first hand experience, but I want a good one so please guide me further! Also keep in mind Im trying to keep expenses down for a variety of reasons, but I dont want to hurt the condition of my car, esp. after Ive spent so much keeping it in optimum condition so far!
Please further advise; thanks a lot!
@Saifullah
Where can I get this from in Isb, and how much does it cost?