sorry if its a repost but....

1. What tire pressure should i be running my 18" cs wheels in 78 deg/ Max. Humidity: 25% weather?

2. When is my 2.7 best balanced? when my tank is 1/4,2/3, 3/4 or full fuled

3. Is 93 octane really going to make a diffrence? (im running 91)

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HP is irrelevant