Premium vs. Regular?
Just out of curiosity, what happens if you use regular fuel in a car for which premium is recommended?
You may experience loss of performance, heavy spark knock (knocking from engine which robs power and may cause engine damage) and eventual engine damage if the heavy spark knock continues.
Also the worst part is along with what littlehorn and papa have said is that if there is damage, and there is a warranty on it, it will be void and you will be left holding the bill (my bro is a sevice manger (toyota/Lexus), and this has happened on a few FG's.
but i do beleive that th 05 Acura has "spark enchancment" DON'T quote me on that, you will have to check your owners manual (if you dont have one, call a dealer). but you can run reg but the car will not preform as well as with what it was designed for.
A friend at work has a 04 (he loves it) and he can run either, which is good seeing I live in Canada and gas is $1.10 a litre (or $4.20 a us gallon)