Can you go from regular motor oil to synthetic oil in a 2006 Toyota Highlander?

Yes, you can switch from regular motor oil to synthetic oil in a 2006 Toyota Highlander without any issues. Synthetic oil can provide better protection, improved performance, and longer intervals between oil changes compared to conventional oil. Just ensure you use the viscosity and specifications recommended in the owner's manual. It's a good idea to change the oil filter as well when making the switch.