How long does synthetic oil last in mid size car 3000, 5000, 10,000?

I know it last longer than reg' oil but how long can it effectively last before its brakes down.How long does synthetic oil last in mid size car 3000, 5000, 10,000?
Usually about 7500 to even 10,000 depending on brand. Toyota recommends Mobile one to be replaced every 7500 miles.How long does synthetic oil last in mid size car 3000, 5000, 10,000?
If most of your driving falls under severe driving conditions, frequent short trips, lots of idling change it every 5 thousand miles, if the majority of your driving is highway then no more than 10 thousand miles.
The big thing with synthetic oil is that it doesn't burn off of the cylinder walls AS EASY as conventional oil when the spark is lit off. But here's the thing-in our shop, at least, oil change intervals aren't about changing the oil-its about having a skilled , professional eye looking at everything under the hood, under the car, checking tires, etc to keep a small problem from turning into an expensive one. Henry Ford was quoted as saying that he'd GIVE his cars away if he was guaranteed the parts and labor to maintain them, and the OE's make 'way more money from repair parts than they do the cars-so go ahead, leave the oil change intervals at 7500 or 10,000 miles-the oil can take it.


But can your wallet take the repair bills from neglected leaks, etc?


And by the way-its been our experience that switching to synthetic oil if the car has more than 30K on it WILL leak oil-the synthetic seems to find any and every weak seal and exploit it!
read Amsoil's recommendations: http://www.amsoil.com/news/oil_drain_int鈥?/a>


a real eye opener on the old 3,000 mile oil change interval