What is compulsory is keeping the frame rate (fps) capped. Vertical sync is the best way to do that if it can be arranged, some players especially on Win 10 need to use Nvidia Inspector or RTSS in addition to (not instead of) vertical sync to be effective.
Unlike newer games, TS3 has no built in fps limiter (TS4 has one) because back when the game was designed in 2008-09 most cards on the market were not capable of throwing such high frame rates. This has changed as time has passed. Frame rates in excess of the refresh rate of your monitor are the equivalent of digital noise that your monitor will never be able to interpret and if they run into the hundreds or thousands they make the card work way too hard for nothing. They also lead to graphics glitches, screen tears, lag, crashes, and after a while can overheat and burn out your card on you.