cant figure out what the difference between these two ring sets are! one says low tension 3rd ring and the other says standard tension 3rd ring??

Plasma Moly Low Tension Piston Rings
1st Ring: Ductile Iron, Plasma Moly Coated, Barrel Shape
2nd Ring: Cast Iron, Phosphate Coated, Taper Face
3rd Ring: Carbon Steel, Chrome Plated, Low Tension

Plasma Moly Standard Tension Piston Rings
1st Ring: Ductile Iron, Plasma Moly Coated, Barrel Shape
2nd Ring: Cast Iron, Phosphate Coated, Taper Face
3rd Ring: Carbon Steel, Chrome Plated, Standard Tension

which ones should i go with! i was going to use these je forged low compression pistons but decided not to go with them but the rings that are recommended for those pistons were the ones with the low tension ring!

now the ones i ordered also je forged but they have a less dish on them and the rings that are recommended for them are the ones with the standard tension 3rd ring??

which ones should i get?

thanks

 

The third ring is an oil control ring, not a compression ring per se. If the upper rings were different, then you may have a compression problem if you were running higher compression ratios. Just a note: 5.0 mustang engines run low tension rings from the factory. The rings seal but allow some leakage. Those engines have been pulled-down with 200k on the clock and still have the original factory hone marks in the cylinder bores. I've known some to go beyond the 500k mark without a rebuild. Higher tension rings have a tendency to wear quicker due to a more positive seal in most cases. Rings like Total Seal (file fit) wear relatively quickly compared to rings with less tension (compression rings).

 

Low tension rings reduce cylinder wall friction & free up a few more HP compared to std tension rings. Yes some cars use lower tension rings from the factory, but are still generally higher tension than the low tension "race" type variety from the aftermarket. Many of these rings, will have oil control problems unless used with a good crankcase/vacuum pump evacuation system. Remember that oil contamination in the cylinder reduces power & can cause detonation. Used properly, they are good for their intended purpose, but can cause grief if used of a regular street motor where they are not needed.

 

Bottom line: expect to pump oil with low tension oil rings. These have no place in daily driver street use.