I was wondering how precise are they? Close to oem? I test fit them on a scrap D16y7 piston to see how well it fits and it seem to be hard to get in the grooves. I don't know if D16y7 piston are different from D16a6.

 

i dont know the quality of the rings. i did instal those on my car and it seems to be fine.
The d16y7 has the same bore so...
if i was to guess ,
they can be hard to get on the piston if you didnt clean the grooves out

 

It's like the rings don't want to go in and I have to press them in hard.

 

new rings are a lil hard to put on some times the do make tool to help out

 

just be careful doing that, you can break a ring when you go to compress them for instalation
I actually did break one when i did mine.
have you double check your pat number?