Ive been reading people in this section (not surprised its the EF guys) running 91 or 93 in their D series because it "cleans" the injectors out, lasts longer, and the car runs better.

The engine was made for 87 octane.


So what gas do you use?

 

e85 or bust

 

what motor are you running and what mods are done?

 

unleaded

 

87...then 93 once every month or so...that's just what I was always taught by older car guys...run 93 once every now and then, to keep it clean

 

i usually run 91 cuz its less than 20 cents more than 87 usually

 

So you run 91 only because it's "Only 20¢ more." ? No other reason?

 

87 octane

 

91 just cause previous owner did

 

Makes no sense.

 

if it's an older engine, you should prob be running something a little higher than 87, especially if you start to get a ping

 

89 mid grade in my 91 si crx gem

 

Thanks for agreeing with me, it appears he might be trolling. Lol.

 

87 even though once in a while i mix in 91 shell gas cause i dont know if its in my head but i do see a slight increase in mpg. again its probably in my head either way its 87 all the time.

 

91 fukk it cuz im ballin.....lol naw jus feels better i know 87 cloggs **** up,,,

 

93 octane, because I had a D15B vtec running a P08 and it wouldn't run worth crap with anything less than once I ran out of gas and my dad brought over some 87 octane to get me to the gas station and it sputtered and pinged all the way there. Now, I have a zc vtec with a ecu from pherable, and he set it to only run 91 octane and higher and there isn't any 91 around me only 93 and 105.

 

87 octane..... you guys running 93 are just paying for those oil rigs FYI buy more 93 so my gas price will go down hopefully, unless it runs on alcohol read your owners manual!....Unless you want those extra horses of course and less change in your pocket, but look at the bright side all your friends will say dang... i didnt know that thing took 93!!!

 

I use 93 because I know that the block and head have both been decked at some point, but I dont know how much, and it has a thinner head gasket. I have no idea what the C.R. is so I run 93 to be safe. If it was a stock motor I would run 87 no doubt.

 

Understanable, but i wouldnt run no more than 91, 89 whatever you can get. if i was driving a Ferrari i would run 93 sure, but a 4 cylinder honda come on guys.. unless your pushing more than 250+ hp but how many are doing that (not saying none are but most are not)

 

^^ exactly haha. These guys think theyre running V10's with 500+ HP under the hoods of their CRX HF's hahahaah.




91 octane brah, i get them MPGz and horsepowerz.

 

Where I live its 87, 89, and 93. there is no 91.
Its my drag/autocross car so at least 50% of my time spent in the car is hard driving.

 

I run 92 octane in my 89si with stock engine. I run 92 in every car i have though i think it just feels better

 

You high octane guys are wasting your money, unless your engine has been built and/or tuned for high octane fuel.

Detonation is when the fuel actually explodes all at once (multiple flame fronts), rather than having a controlled burn (one flame front). In that case, the cylinder pressure hits maximum before the optimum crank angle, putting all or most of the energy into the piston, wrist pin, bearings, crank and caps, rather than putting it into crank motion.

The octane rating of the fuel tells you how resistant to detonation the fuel is. Octane molecules burn in a much slower and more controlled fashion than heptane molecules do. That octane rating of the fuel says that its detonation resistance is the same as fuel that has that percentage of octane to heptane molecules. For example, 87 octane gas has the same detonation resistance as a fuel made up of 87% octane and 13% heptane.

With a stock tune designed for 87 octane fuel, the compression, air-fuel-ratio and timing are set to not cause detonation. A higher compression engine and/or a tune that gives you a leaner AFR and or more spark advance can give you higher horsepower, but puts you at risk for detonation and resulting engine damage. That is why you need to run higher octane fuels to keep those engines safe.

I strongly recommend that you all read the book "Engine Management: Advanced Tuning" by Greg Banish http://www.amazon.com/Engine-Managem...3274545&sr=8-1

It is only $16 and you will learn a LOT.

 

Actually my stock 95 prelude required "premium" (93), it only had 160hp, and from my understanding a lot of honda engines are finely tuned machines, and many honda engines do require premium gasoline. )As a matter of fact MOST honda engines (even some civics )are pushing out a lot more hp/liter than most other brand cars.

Now I also understand in this specific forum we ARE talking about a lot of engines that are a bit dated, and most were designed to run on 89. But most mechanics WILL tell you when these old engines start "pinging" you need to up your octane to solve the problem and run cleaner. 89 to 91 is good, or what I do is just run one full tank of 93 once a month or every-other month, or when I hear a little pinging...it clears it right up, then back to the good 'ol 89

 

Uh... shell plus.. It ran great until the timing went bad.