Isobutanol may be converted into predominantly C12+ olefin oligomers under specified conditions. Such methods may comprise: contacting a feed comprising isobutanol with a zeolite solid acid catalyst having a MWW framework under conditions effective to convert the isobutanol into a product comprising C4n olefin oligomers, wherein n is an integer having a value of two or greater and about 80 wt. % or greater of the C4n olefin oligomers are larger than C8.