91' tsi fwd

Just recently went for an e-test at crappy. They said there was too much blue smoke when they went to do the rolling test.
If the car sits and idles for awhile and then you go to take off that's the only time it smokes.

How much harm does adding those really honey-thick additives to your oil do? You know the 'stop oil burning/leaking' ones.

It's my beater and I'm not concerned about performance anymore, I just don't want to blow it up and pass the e-test so I can get one last year out of it.

Any suggestions?
Thanks