All presidents, I suspect, need to do a little lying. It's part of the politicians job description. Richard Nixon and Bill Clinton famously came acropper on some of their more outrageous lies. Of course telling a lot of lies doesn't necessarily make one a good liar. Nixon had a way of looking like he was lying even when he accidentally told the truth. Clinton's lawyerly evasions were a give away.
In the lying department, no President in my memory could touch Ronald Reagan. His twin strengths were the degree to which he was unconstrained by logic or consistency and his apparent ability to believe utterly in his own mythology.
As his daughter (Patti Davis) wrote:
...this “the most aggravating aspect of discussing anything with my father. He has this ability to make statements that are so far outside the parameters of logic that they leave you speechless.”
Perlstein, Rick (2014-08-05). The Invisible Bridge: The Fall of Nixon and the Rise of Reagan (Kindle Locations 10954-10956). Simon & Schuster. Kindle Edition.