A little food for thought: http://www.edmunds.com/car-care/stop...-your-oil.html

 

I'm not sure about the other 5th gen GCs but the '08 owners manual prescribes a 6 month/6,000 mile oil change interval, which I have stuck to despite the wishes of my local Dodge dealership. It also says that "you may use synthetic engine oils provided the recommended oil quality requirements are met, and the recommended maintenance intervals for oil and filter changes are followed."

The linked article mentions the business that the 3,000 mile oil change interval brings in to the quick lube industry just in oil changes - the article doesn't mention the income that industry generates in upselling people on things that they possibly don't need and in extreme cases can actually do harm to their car. Bringing customers in for oil changes more often than they need to be just gives the quick lube places more opportunity to sucker people into such sales.

 

manual actually tell to not exceed 10,000km and that regular or synthetic oils.

 

On my 99 Civic I do yearly oil changes on Synthetic and a premium oil filter, and I hardly do 10,000 miles in a year because I'm unemployed. My 2005 SXT, the oil change is 1 year old today but it only has 1245 miles on the Synthetic Oil with a Bosch Premium oil filter. -- I'll give it 4 more months until my next oil change, which will be an expensive 100% Royal Purple Oil change with R.P. filter too.