oaky its 45degrees on a 16v engine, and thats only valid on the earlier non self adjusting tensioner types. The probel with the self-tensioning tensioners is the holes are quite shallow, so you have to take more care with the old allen key/ bent fork method. I got a proper tool for cheapy which makes it much easier.
edit: oh and you can sweap to the earlier cheaper tenioner if you swap the stud & nut over from an older 8v/16v engine. Given the choice I'd go for the self-tensioner tho, you know its always gonna be spot on then.