Does the Lexus gs300 have a timing belt or chain?

The Lexus GS300 has a timing chain instead of a timing belt. Lexus/Toyota chose to use a chain inplace of a belt because it will last a lot longer. Some chains have been known to last longer than the car it is installed in. There are other reasons to use a chain as well, belts tend to stretch which causes small variances in performance. There are many reasons to use a chain over a belt but some manufacturers still use belts because the cost is a fraction of what a chain is to produce and when You are trying to price Your vehicle at the lowest possible msrp, a belt in there can help.