Not sure, but over the last few months my 05 has been feeling sluggish and non responsive to me; and a maybe a little slipping of the transmission. I changed the trans fluid and it may have helped just a little. -something to do with the traction control? If I punch it from a stop when it shifts from 2 to 3 it pulls to the left/right a good bit. Dealer said everything shifting ok. Part of this could be due to the fact that i am now driving a new 5.7 Tundra and I may be comparing the van acceleration/shift to the super responsive new truck. I am at 63k with the van, I am going to get a 60k service in the next couple weeks- I will have have my service guy change the filter and check for another opinion on the shifting.