Mopar Action said to avoid low tension rings for a street motor unless you have absolutely straight and round cylinder bores. Does this mean that most engine builders can't work to the precision that is necessary for these rings? The coment related to oil control.

I think it would be good to use this type of rings on a street motor for less wear, better fuel economy, slightly more power. But apparently it is not a good idea except for the race track?

A good engine builder will "set" the oil ring tension just like you set the top and second ring end gap.

You install the oil ring only in the piston and stick it in the bore and "feel" how tight it is. you can adjust the load by filing on the expander where it butts together.
(Don't mess with this unless you know what you are "feeling for" and have some extra ring packs to play with.)

Truth is that oil ring tension is more of an issue in the high RPM range, for low RPM use, good oil control is more important.
DD