[fdeno]

Other posts here state you need to use hi-test gas when towing per the Owner's Manual but I haven't verified that myself because I don't tow that much. Might want to check that out.

 

[fdeno]

I would not put regular case while towing as an experiment to see if premium is required because pinging occurred. As someone suggested.

Pinging is bad news and sometimes so subtle you don't hear it....