You can use any brand that matches the grade oil that the 2013 GMC Terrain's owners manual calls for.
〉 Answered on Jan 27th, 2015 by Amy Mattinat, Owner and Author at Auto Craftsmen Ltd
Synthetic blend oil is a combination of conventional oil and a fully synthesized oil. It has to do with the size of the molecules it has been refined to. If you have continually been using a synthetic blend, then continue to do so. Changing to full synthetic can cause build up to loosen and leaks may occur. The brand of the synthetic blend is usually not a consideration. It is the mix that is important.
〉 Answered on Jan 27th, 2015 by Gail Dunn, Owner at Women's Automotive Connection