Can't remember which version and all that its the original motor in a 88 CRX si. I'm using it for Autocross and I'm curious about how high of an octane the stock motor can take. We're just running 91 from the pump now

 

87 will do just fine

 

Stock motor run only what you can get at the gas station.
Only when you build a motor and put on a tune should you run anything higher and only at the advice of the tuner.
Your autocrossing anyway so theres no gain in going higher than 91 other than you wallet getting lighter for paying for more expensive fuel.
Personally I'd use 87.

 

Agreed. Run 87 unless you change the compression.

I had a D15B (jdm sohc vtec) that I ran 92 in for a while. I finally wised up and put 87 in it, it ran much better.

 

More octane doesn't increase power if the motor isn't built for it. Just a waste. If it doesn't knock on 87, then keep using it.

 

14 years of endurance racing with a 10 to 1 d16, ran 93 pump octane no problems. In fact still running 93 octane in my 11 to 1 type r. I would say 93 would work for you.

 

Why spend the money??

 

If you are questioning why pay the premiom for 93 octane, You are probably right, 91 would work, in our race car, we busted the rings out a couple of times on an amped up D16, just trying to be safe by recommending 93 octane. Go ahead use 91 if $2 a tank is important.

 

I think im looking at track where 91 its close to 5.00, or more a gal vs 3 something at the gas station.
Autox you'd probably wouldnt run out of gas the whole day in 60 second runs.
A track day is gonna be much more expensive than autox.

 

i dont really understand the need to run anything over 87 in a bone stock d16a6 even with i/h/e it will give no advantage

 

Running higher octane will not give you more power unless your engine is tuned to take advantage of it. So all you would be doing is spending extra money for no reason. At the same time, there is no risk or danger involved in running higher octane fuel. However you will be throwing a little bit of money away.

 

Correct.

Higher octane fuel burns more slowly, as in, it takes the flame front a longer time to propagate across the combustion chamber. This is how it combats pre-ignition and detonation (knocking and pinging). If your stock engine is prone to knocking and pinging, then increasing the octane rating of fuel used should help combat this, but in no way increases engine power.

On a tuned racing engine, however, a higher octane rating can be of significant benefit towards power increase. The slower burn rate of the fuel allows for greater ignition timing advance and more aggressive cam profiles, among other things, and ultimately, a greater/more even combustion pressure across the top surface of the piston when it needs it most, about 15* BTDC, but the engine needs to be tuned for this. On your stock motor, since it hasn't been tuned to reap these benefits, does not require a higher octane, no matter what you're doing with it, unless, as I said before, it's already knocking and pinging. If it is, you probably have some other issue, such as deposits in the water jacket surrounding the cylinder walls causing local hotspots in the combustion chamber, which are prone to induce pre-ignition or detonation.

 

Lol nope just rebuilt not even 1k miles on it

 

I could see running higher octane if you were knocking or running a lot of timing, but really why bother? You would be better off saving the money for other things, like a nice tire pressure gauge or air storage tank.

 

All this made me think of something else. What oil should I run? I live in Oklahoma where its nice and hot. My civic has 5w30 idk what the crx has in it now. Is 5w30 good or should I go down to like 5w20?

 

oem clearances = oem grade oil