Teams can now carry over unused sets of tyres, and safety upgrades have been introduced to Indycar chassis: http://motorsportstalk.nbcsports.com/2014/03/18/new-indycar-tire-rules-chassis-upgrades-announced/
Instead of drivers incurring grid penalties for unauthorised engine changes, the manufacturer will receive a points penalty instead: http://motorsportstalk.nbcsports.com/2014/03/18/report-indycar-grid-penalties-for-unapproved-engine-swaps-gone/