No matter the brand 5W30 is best all year protection, however if you are going to change viscosity grades 10W30 for late spring, summer and early fall, 5W30 for in-between. Good rule of thumb is to use viscosity that is best suited for the end of your change cycle.

By the way Valvoline.

99 Sport SE - Zetec Mods: My wife vacuumed it last spring , my son wiped up his hot chocolate spill in December. My daughter found the tooth she lost last week .