I don't know about adderal oscar - but my tolerance with dexedrine spansules is gone. I'll tell you of that and it should be nearly the same - chemically they are nearly the same just different salt suspension I think.
I found tolerance fast on 10mg 2xday. Within maybe 30 - 45 days I was feeling "slippage" and the old noise and chatter was back.
I found moderate tolerance on 20mg 2xday. about 3 months in I felt the drag on me - temptation to give into urges and such. During the peak in the day though the pills were very strong and no extra side effects.
40mg 1 or 2xday - no tolerance! I now have been on the same dosage ever since my MD upped it. The strength is consistent, the effect the same reliable every day. I do get cramping in my gut if I don't eat, or if I eat one big meal. I have to snack before work, bring 2x snacks with me to nibble at break and have a light meal at home. Then it's not bad - and I take dicetel which smooths out the intestines fine.
I don't know conclusively if that will be the same for you - but what I did was try the one dose, as soon as I felt the fading and lack of energy I went in and got it upped a notch. Kept doing it until it worked permanently - or I hope so.
Let me know if that helped at all!