10w-30 is correct.5w-30 maybe ok if you live in Ohio ect.were it gets real cold. 10w-40 is not good because they use too many stabilizers to cover the wider temp. range.
2015 Red 2 door(half doors) Sport base.Orderd 5/29/,D-1 6/4,KZ 6/24,Delivered 7/09/2015,Picked Up 7/15/2015(!.5 in. lift 18/59 springs),265/75/16 Duratracs on Mamba 16x8 rubicon wheel clones.