The retraction settings tend to vary between the many types of PET-G available, but generally spoken a value twice as big as the one for PLA should be ok as long as you stay below the maximum retraction lenght (<4-5mm with the stock-hotend, <2mm with the all-metal-hotend).
If you're printing without the all-metal hotend there's a chance that your PTFE-Tube has already degraded (due to the high temps which PET-G usually needs for a constant flow) which could also be a reason for your jams.
The retraction settings tend to vary between the many types of PET-G available, but generally spoken a value twice as big as the one for PLA should be ok as long as you stay below the maximum retraction lenght (<4-5mm with the stock-hotend, <2mm with the all-metal-hotend).
If you're printing without the all-metal hotend there's a chance that your PTFE-Tube has already degraded (due to the high temps which PET-G usually needs for a constant flow) which could also be a reason for your jams.