petg print very brittle

[Ama-fessional Molder]

but on the whole I'm better printing pet-g cooler rather than hotter ?

Which would be right in line with what was stated, that hotter temps risk degradation of the material.

When processing plastics the lowest temperature you can manage to get working is always preferable.

Ok it turned out to be wet filament. Put it in a 90 deg f heater overnight and prints are much better. Printing at 245 and 60 looks pretty good. Just some fine tuning and I should be in good shape. Thanks for all the help.

Score one for science!

That said, you will see additional improvements if you dry the parts to a much lower moisture content than is possible with hot air alone, however if you are at an acceptable point then I see no reason to investigate further.