I bought a 2004 sr5 v8 4runner with a 10000k miles on it, 6 weeks ago. The truck ran great fast off the line, took it to the dealer for oil change. They told me The timeing belt should be changed said ok. Got it back and it run ok but it seems to slower than before I brought to them.They put 0 20 w oil in it I did not know it till I looked at the bill a week later, I told them to take it out they said it was ok, put in 5 30 w in it. Any ideas why the truck seems slower, and how to fix it. They girls are really stupid.