B-Hadron Lifetimes and $\Delta\Gamma$ at the Tevatron
  We present new results on the lifetimes and widths of $B$ hadrons based on 300-450 pb$^{-1}$ of data collected by CDF and D{\O}at the Fermilab Tevatron. Lifetimes were measured in semileptonic decays as well as fully reconstructed hadronic modes. A new measurement of the width difference between $B_s$ CP eigenstates, $\Delta\Gamma / \bar{\Gamma} $, in $B_s$ decays to $J/\psi \phi$ is also presented. 
R.J. Lipton (for the CDF Collaboration and D{\O} Collaboration)