Last week, I switched my dad's Camaro from 30 to 10w30 motor oil. The car ran its quickest time ever that night by .03 in the 1/8 and the 60 foot by .01 and the weather was not the best I've ran in. No other changes were made and after reviewing my notes and seeing my friend's car run the same times two weeks in a row, it looks like the thinner oil was the reason. Does this sound right? I may have to get some more passes in to know for sure but it looks good on paper.

Absolutely! Try 30W5 in Mobile One and see what happens!