Engine oil

I've used Mobil 1 in my cars/trucks for many years with great success, my recent purchase 2010 Tacoma 4x4, 4L V-6 one owner with 100,000 miles looks very well maintained but I don't have actual maintenance history. I don't know what kind of oil the previous owner was using but I would like to start using Mobil1 for this truck. My concern is that if you switch from regular oil to synthetic oil the engine may start leaking oil from seals/gaskets. Any recommendation/suggestions would be appreciated. Thanks.