PETG Temperature Question

I’m using some Overture PETG and the nozzle temp they suggest is 230-250. I’ve been printing it at 265 so I decided to run a temp tower to see if I could lower it. I did dry it for several hours first before I did this. The tower started at 250 and went to 290. It had terrible layer adhesion and snapped between 250 and 255 when I pulled it off the plate. The 250 level and brim were stuck to the PEI sheet. The filament looked pretty good between 270 and 275, with some minor sagging on the bridge sections. I’ve not ran it through any other calibrations yet.

So am I printing at too high a temp? Are people able to get great prints at the lower temps for PETG?

You should keep using the higher temps since you are getting good results. The manufacturer recommendation isn’t always a good option for printing fast since the layer will have under extrusion issues and be weak like you are seeing. Just using a hardened steel nozzle would typically require you to up your temps by at least 5-10C to get the same level of results since it doesn’t have as good of a heat transfer as a brass or stainless steel. Using a temp tower like you did is the best indication of what temperature to print at, the manufacturer recommended is just a guideline not a requirement.