what to use to soften vinyl seats

[62nwhite]

I have a 68 charger with buckets. The seat covers are in great shape. I need to replace the foam. I was told to soften up the vinly because it probably shrank before replacing the foam. Order from Legndary interiors. Or just repalce all seat covers because of future problems with the stitching letting go. Any thoughts on what to use or what to do, would greatly be appreciated.

[68 RT]

I recovered my seats in my 68 15 years ago but did not replace the foam. Just replaced the foam over the winter. So I would say if your seat covers are in good shape reuse them. You will be able to tell when you get them off. Even with new covers you will want to warm them up a little before install. I lay them out in the sun or winter time used my heat register in the house.

[john108]

This doesn't answer your question but was my thinking.  I ordered all new Legendary front bucket (+insert) and rear upholstery.
I figured my original stuff was 47+ years old, even though  the rear seats looked like nobody ever sat on them.

[NOWIFE]

Like 68 RT said, lay the covers out in the sun and let them soften up.  The last time I did it, I laid them on the dash of my truck in the hot sun. 

A few tricks I've learned over the years:
When you install the bottom cover, use long black zip ties to go around the wire that's inserted in the fabric, use the old holes from the hog rings.  This allows you some wiggle/fit room while you are trying to center them or even them up.  Tighten as you go.  You can then apply the hog rings and then clip the zip ties, or leave the zip ties if you don't have stainless hog rings.

  I also wrap the foam in cellophane or shrinkwrap to allow a slick surface while installing the covers (usually only on the backrest), then once the cover is basically in place, but not secured, reach in and remove the cellophane/shrink wrap.  It makes the task a little easier.   

  Vinyl isn't like leather and is hard to soften once it looses it's soft polymers, but if you warm them up and use a silicon based solution it will help a little.   The heating opens the material up and allows the silicon in, but it can be messy and make the seats way too slick.   Maguieres makes a decent silicon based vinyl treatment. 

Just my two pennies of experience

[Laowho]

I've read that for general reconditioning the old trick is baby oil, depending how far gone/dried the vinyl is. Maybe sun-heat them then add some?