I started using synthetic at 10k miles, because I plan to keep this vehicle for the long haul. I still get it changed every 3-6k miles, though.

The official dealership response I got in regards to synthetic oil is that it's no problem with them if you use synthetic oil at all, HOWEVER your warranty requirement that you keep up with the maintenance schedule does not change.

Likewise, if you change your own oil they HIGHLY recommend that you keep receipts for the oil you buy and mark the mileage you had at each change.

I don't know how aggressive they are with denying warranty work due to oil change history (or lack thereof), but it would suck to lose out on a repair being covered because you were going 8-10k miles between changes on synthetic vs. 3-6k on dino.

Note that this ceases to be a issue at 36k miles (or 100k if you extended the warranty), and I don't know what the requirements are for the lifetime powertrain warranty.

 

I talked to the dealer's service and they said that 2008's, except the engine have Synthetic fluids in it. Should I believe him?

 

I will plan on just getting the Engine Oil Changed to Synthetic!

 

Just Did the Engine Oil At the Dealer With Mobil 1 Full Synthetic. Much Better now. 5W-20 at 64 miles.

 

Look in your owners manual and see what it requires, that will tell you for sure.

 

I thought you weren't supposed to switch to synthetic oil until the motor is broke in and the rings are seated? I don't know where I heard this, mabye somebody was lying to me. I figured 3k was a good time to switch.

 

I waited until my second oil change at 6K just to make sure everything was broke in properly.

You will find not everyone will agree on this, so its up to you to decide.

 

There have been theory's that you should run dino for 6-10 K to ensure engine break-in, especially in diesels.
Not sure if that is still valid or not.