I understand that there is no exact answer, however, I do think it's possible to give educated guesses and ballpark figures. Similarly how you might say there is something wrong if you can't OC E8200 to 3.4Ghz, you might say there is something off if I was seeing 80c under load. Pardon the exaggerations.
My voltage is left on auto (I have made a question about it here http://www.tomshardware.co.uk/forum/269246-11-motherboard-settings-
overclocking) so it seems to vary, but the highest I have seen it at is 1.288v