Ok, something primarily for forced induction cars...
People I keep talking to are whining about running premium, it's "too expensive" they cry. What? Since when?
I have an 18 gallon tank. On average I don't run it to the E line, so likely I'm putting in 15 gallons at a fillup.
Assuming you are paying $4.09 a gallon for regular that is $61.35
Assuming you are paying $4.29 a gallon for premium, that is $64.35
That is A total of $3. $3! How FAR can you go on $3? Lets say you get 25 mpg (I know, you all probably do much better unless you keep your foot in it), that is 0.73 gallons, a total of 18 miles you can go on that $3. IF you get better mpg with premium (most cars do now that have the high/low octane tables properly setup), it is EASY to get better mpg with premium than low octane.
The % difference is mimimal. The distance you can go can really end up being much improved.
So why NOT get a good tune if you don't already have one, and enjoy running premium?