How often must I change synthetic oil ?

My Nissan has 60K on the engine and, I normally use conventional oil and, change every 3K. Id like to try synthetic oil but, need to know how often it needs changing.How often must I change synthetic oil ?
It's not just the dirt, but the breakdown of the viscocity of the oil that makes it 'wear out'. This is why synthetic can go longer - it lasts longer in that respect.





5k is a good general rule. A change before that is just wasting money.How often must I change synthetic oil ?
Just as often as your car manufacturer recommends for regular oil, most likely 3-5k. Here is my reasoning, your oil will still get as dirty at the same rate as conventional oil, if at 3k it is still clean, keep going, you be the judge. I live on a gravel road, so my oil is dirty enough to change at 3k.
I have used synthetic for years in a F-150 with 180,000K on it and I change the oil at 15,000K and replace the filter every 7500K.The majority of my driving is done on bush roads, and the trucks does not burn any oil.In our car I used conventional oil and change it every 5,000K
Same as with conventional oil. The reason you change oil is because it gets dirty. Synthetic oil gets dirty just as fast as conventional oil.
5000 miles
7500
Ifn you drive like a racer then 4000 if normal 5000 to 6000 if you dont drive very long distances or hardley at all then 7000
Everyone is going to argue this. But it would be ok with just changing it every 6000 Miles.