Does the 2005 Lexus RX330 have a timing belt or chain?

The 2005 Lexus RX330 is fitted with a timing belt, which Lexus recommends replacing every 100,000 miles due to routine wear and tear. While this is a recommended replacement and not a required one, one of the worst things that can happen to You is having a timing belt fail catastrophically while You're on the road. Failure like this can cause loss of power or control, and can injure or kill the driver or others. While timing chains have an effective lifetime of use of around 250,000 miles, Your belt is going to be much shorter. The good news is that it's also less expensive to swap. Therefore, there are both advantages and disadvantages of having a timing belt, but overall You're in a pretty good situation -- 100,000 miles is in the upper echelon of recommended distances across different manufacturers.