Originally Posted by Nathan1234

Yes, you can put synthetic in. You may not see much difference, but it will last longer and could give you slightly better gas mileage. I'm not sure I would spend the extra $$$, though, since you only really take advantage of synthetic's great resistance to breakdown if you are towing heavy loads or doing other things that signifigantly inrease the fluid temperature. The flush would definitely help, though (although you will likely still not notice that).