QUOTE(:3mushy:3 @ Sep 20 2013, 07:52 PM)
The answer is simple. Your engine might need to be regulated for every 10k if you used fully synthetic, but what about other parts? Some people have concerns about this, but usually your car will be fine with 10k interval because for every car, they already have a schedule of which part needs to be replaced at what interval, for example, you need to change your timing belt at 80,000km.N ot only Proton, Honda, Toyota, Peugeot, Ford, they all recommend 10k interval.
The SA recommend semi-synthetic for 5k is because, well, it is only good for that mileage. Full-synthetic engine oil can last until 10k. If you're going to do 5k intreval service, why do you need the unnecessary and more expensive fully-synthetic oil that can last up to 10k?

I see. Thanks for the explanation. I have a Honda Accord, and the service interval is 5k or every 3 months. Like this I will go for the 10k service. Not bothered with visiting the SC every 5k
Can Preve owners try this on their car. Need to check on my Suprima:
After starting the car before driving, try pressing the foot brake while in "P". Not the initial foot brake press to start the car. Press once or few times after that. Is there a weird "tak" sound coming from the centre dash below the USB ports? Weirdly this only happens when the car is stationary and in P, and not from N going to P.. Does not happen when driving, does not happen immediately after starting the car. Actually I am not sure what it is. Under normal circumstances, no one will ever press the brake few times after turning on the car, car stationary in "P" and pressing the brake.
Can someone else verify this?