want a highly carbonated batch

i sometimes find a extremly carbonated drink very refreshing. Whats the maximum amount of bottling sugar you can add at bottling without causing bottle bombs? then if i add that amount, would adding a tiny bit of olive oil or something stop any gushers(i dont really care about the head)?

make a Belgium whit

I don't know what kind of pressure a beer bottle can hold but a 2 liter soda bottle will hold something like 100psi. I would think the 20oz bottles would also hold a similar pressure. Might be worth storing the beer in the dark just to prevent a messy clean up. Plus you can watch them and you will see them expanding and know you need to relieve pressure before it explodes.

Toughest bottles are champagne. Heavy reusable soda bottles (eg Mexican Coke) are tough too. German 500ml bottles (eg Ayinger) will take a lot of pressure. 4 volumes is about the limit for typical longnecks.

If you want a really carbed beer use champagne bottles they can hold ridiculous amounts of pressure without risk of explosion. For an experiment I once used a champagne bottle with a hefewiessen and about 15 carb tabs, it didn't blow up but even after a month in the fridge it was all foam. So remember champagne can have a lot of carbonation because it doesn't have the head retention of beer. Also make sure your bottle capper does a good job of crimping the caps, I've had caps blow off on one of my older batches with my old capper.

will the tiny bit of oil help with the foam?

yeah make a wit or an American Wheat beer - it will seem more fizzier