I have a simple T4 template and want to write this comment to the output:
// só para os serviços que têm ORIVIRTUAL no conteudo

Instead of writing that comment it writes this one:
// s�para os servi�os que t�m ORIVIRTUAL no conteudo


notice that characters with 'ó', ´ç´, 'ê' are replaced with ? here in the post but in the VS this caracter is a square

In hex the chars 'ó', ´ç´, 'ê' are replaced with:

0xEF
0xBF
0xBD

Looks like a encoding issue, have you tried the "Encoding" attribute of the "Template" directive?

Looks like a encoding issue, have you tried the "Encoding" attribute of the "Template" directive?