As with any mantra, the pronunciation and meaning are helpful for the fullness of the effect of Savitri. For that matter the rhythm is even more important and that depends more on the right pauses and intonation than pronunciation alone.
However if that were a precondition very few, including many English speaking readers, would qualify to read it. What is much more important is to read a little everyday, to read slowly and with sufficient quietude and then meditate upon the lines that have been read.
There is another way which can be combined with the former. It is to read with faith and aspiration in the heart knowing that it is the Word-body of Sri Aurobindo, a living reality draped in word and sound. If one does it with sufficient faith then the rhythm begins to emerge from within and the mantric power works bypassing all the rules and cannons of reading.
If one wants to know how to read it is best to hear the Mother’s readings of Savitri that are available on this website.