whats the diff between the 2? is there applications where low tension are the go? or should a street strip motor stick to std tension rings? i'm ready to buy but i'm a wee bit confussed over the options. who can school me on this subject?

Pro's; it takes less power to turn the engine over
con's; They don't their job as well as the standard tension rings, unless you are usin a vacuum pump.

Each combo will be different, but the basics are just how much oil gets by the ring you use. Acceptable for a race motor and a street motor are different. A race motor can burn more oil because we don't care about oil consumption in a race motor. The problem is when too much oil gets by the rings then it lowers the octane of the fuel used.

For anything that sees the street, I would not use low tension rings or a vacuum pump.
Stick w/ std. tension rings and some vent lines from the valve covers to a puke tank.

I`m running back cut top and bottom rings (moly top, napier second)w/med oil rings w/out issues on the street no vac. pump.

Two things come into my mind on piston rings, thickness of the face and the tension. I'm almost positive that all the new cars have thinner piston rings than before, 5/16 inch face old days, 1.5 MM or 1.0 MM rings now The last stroker motor I built for myself has 1.5 MM top and 2nd MM rings with a 3.0 MM low tenison oil rings, no vacume pump or crankcase evac. system, two breathers on each valve cover I forgot to measure the rotational break away and rotataional torque but it is a bunch less than the other motors with 1/16,1/16, 3/16 standard oil tension ring set that I have built My next motor will have 1.0,1.0, 3.0 MM low tension rings with a vacume pump Let us know what you decide