I accidentally hit the sidewall of the curb and it caused a small looking rip/tear. Do you think the tire is still good or should I replace it. I have a 4WD.
I wouldn't worry about it, there's a lot of structural integrity baked into modern radial tires:
However, I would deem replacement mandatory if any of the following occur:
This link has detailed information on tire construction.
Would you ever feel comfortable driving the car knowing that the tire is damaged like that? I certainly wouldn't.
The damage could be a lot worse inside. You also need to consider safety of other road users.
Replace the tire is the only advice anyone should give on here.
If you really need a second opinion, take it to a tire fitter and get their opinion.
Replace the tyre as you can't see what damage has been done to the sidewalls structure. The sidewall not only supports the vehicles full weight but it is also subjected to all sorts of stresses and forces in all directions, as well as heat/cold/moisture & grit.
A sidewall split is an open wound for all these wearing elements and as its not repairable you only really have one safe option.