I think you put in whatever the manual states.  If it calls for more than
regular, try a grade lower and see if it causes pinging.  If so, bump back
up.

Please put 91/93 in that sweet a.s engine, maybe you shoulda got the EX.

I used to own a 2001 Maxima SE before the 06 Accord I currently own. It
recomdneds "premium for max performance" after having the car for a month I
tried to use regular in it for a tank. and let me say... I NEVER did that
again.. Modern engines that require high octaine gas have a Knock sesnor in
it, so if you put in lower grade gas than what is calls for, it retards the
timing to compensate for the lower grade gas. when my maxima did this it ran
like absolute crap... also the "knock sensor" has to "sense" the knock
before it can retard the timing, so your engine is knocking before it
retards the timing.... long story short, it only costs your a few dollars
more per fil up (2-3 bucks) to get premium... like i said with my Maxima,
one tank of regular made me NEVER put anything BUT premium in it. I'd say
you might be able to get away with mid grade.. but I'd do that at the bare
min... in my opinion

I think that you read the Owners Manual and go from there for every aspect
of being the owner of a Honda.

That aside, every Honda vehicle I've owned over the years has come from the
factory made to achieve the best fuel mileage using regular fuel. I have
tried other grades of fuel and none of them have achieved any significant
differences in mpg to warrant the added cost of the higher grades.

The Prelude I previously owned developed 200 hp at 7,000 rpm out of 2.2
ltrs.  You had to run premium in it.  The SI developes 197 hp under the new
SAE hp rules which means it likely is comparable to the older Prelude but
with a smaller displacement.  Run 87 octane at your own risk.  But, I have
to ask why you bought the SI.  The EX would have been far more appropriate
if you wanted gas economy on regular gas.

if the manual in my car calls for 87 octane to be used.  then i would use a quality chevron with techron  or shell , or sunoco quality brands.  of gasoline there is  no need to be using a very high octane in a low octane car thats designed to run on 87 octane its a waiste of money.!  and in using it your overheating the catalytic coverter   there by shortening its life if you feel that you need to bump up the octane for what ever reason ? use no more than an 89 midgrade thats more than enough for your engin

--
johnin

I have a 2006 si, I filled the tank and add gas when I hit a quater mark.
The price for filling up to the full  mark is not so bad as filling a near
empty tank. This engine gets good mileage with fast starts and hi revs. The
cost for hi test is worth it for the fun one gets from driving this car.
stay out of food houses and spend the cash on gas.

We take delivery tomorrow evening - she is pretty excited!

Based on the feedback, it will be premium all the way!

PS - she liked the seats better than the EX. That and the spoiler! I know, I
know.......