There has been a lot of discussion on this among numerous communities running this engine. With a good synthetic and any decent filter 7k doesn't seem like much of an issue; used oil analysis confirm this in fact. While I think we can all agree that the 3k mile "rule" is erroneous with todays oils, I like 5k simply because it is very easy to remember and conforms to extended warranty criteria that many, including myself, must abide by if the full warranty is to be honored. Today in fact, for the 30k service, I switched everything over to synthetic (engine, both diffs, and transfer case) and hope to not have to deal with that MESS again for another 60k at least (with the exception of course being engine oil). I will continue to run 5k simply for the convenience of having a very easy to remember service interval and the peace of mind of knowing that it falls well within current oil performance standards, including Toyota's.