RE: DTE oil which one
Wren recommends a minimum of 5% ( 1 quart oil to 5 gallons fuel) ratio on all motors being produced today. This also applies to any of the earlier turbines. The added oil content is cheap insurance against bearing failure.
The DTE Lite is much more user friendly. Compare the MSDS sheet of DTE and that of a Turbine Oil.
I have used more than 20 gallons of DTE without any issues.