hey guys i just got a hatch with a b16a2 swap and ive been told by some people i should run 91 or 93 then some say i should run 87.. what gas are you guys running.

 

the higher the #. the cooler it burns and less chance of detonation.

lower #, usualy cheaper. burns slower and hotter..but can kill the motor if you get a bad batch (if you have turbo etc and pulling lots of timing)

jus put 91 octane and nothing lower. anything lower is like putting diahrea in your cars gas tank......

 

haha thanks man ill just run 91 or 93 then

 

Incorrect, actually the opposite. The higher the octane rating, basically the harder it is to ignite preventing pre ignition in higher compression engines. all automotive fuels burn at the same rate at a constant air/fuel ratio. believe it or not the only reason you cant put 87 octane in a forced induction/high compression engine is because its too flammable!

 

weird -_-

 

so should i run 93 in the b16 or is 87 fine

 

gotta agree with efstyle..

running too high of an octane in a motor with low(er) compression can actually cause it to run worse.. you wanna run the proper octane, basically- the higher the octane isnt necessarily better. there should be info on it somewhere, possibly in an owners manual, but i'd stick with 89-91

http://www.torontocivics.com/f54/b16...-rating-11249/

http://www.ht-archive.com/showthread.php?t=2338071

 

All vtec b series require high octane fuel

 

Wrong. People think higher=better. Its not the case.

Please don't. Run 87.

Yeah. Basically with turbocharged engines the air intake is a lot hotter than a naturally aspirated motor. Pv=nrt. The air intake is pressurized so its a lot hotter and so the temps inside the combustion chamber increase a lot higher which in turn can cause the fuel to ignite by itself before the spark plug sparks the fuel which= detonation which can = blown block/snapped rod/melted piston,etc. Not to mention loose HP since the combustion would be pushing the piston down when its trying to go up for example.

You basically want to run the lowest octane possible without detonation. In this case its 87, anything higher and its going to run like crap since it can't ignite the fuel properly.

 

you have to run premium on my si on the gas cap it say premium only

 

You should use whatever the manual says for the car that the motor came out of, in this case a 99-00 civic Si. My friend has an extremely clean JDM B16A and he always used 93 and when he switched to 87 2 months ago he was surprised how much better the motor felt.

 

87 you will be fine its not an evo man its a honda... Anything higher will cause the car to run like **** if you dont believe us try it see what you think.

 

Honda recommends that you run premium in all b-series vtec's and plus it says so in the owners manual and on the gas cap in the 99-00 civic si and integra gsr.

 

honda has race fuel in the ecu but retarded to use standard pump gas.....ask hondata if you dont beleive me.............................

doesnt mean you can jus throw c16 in though.
lower octane can have ping or detonation...
higher octane IS better...to a point though. anything over 93 you should start to have alittle advance timing

 

on my gsr swap if i run 87 and 91 from any cheap gasstation my car throws a CEL for knock sensor but if i run 91 Chevron she purrs like a kitten

 

There's a big difference between what the manual "recommends" and what is required. For a B-series running standard compression, standard timing, no forced induction, no and head work I can't imagine you'd get any benefit whatsoever from running higher octane gas. Stick with what the manual requires (I'd venture to guess it's 87).

 

Automotives is not about guessing

The only b series not requiring premium fuel are the non vtec version's like Integra RS, LS and GS models....and the Honda crv

Car's like Integra Integra GSR and Type R models and Civic Si and DelSol dohc models use 91 octane

 

Honda recommends 91 octane I believe. Maybe the motor in stock form doesn't NEED it, but I know the engineers at Honda know more about their motors than I do. I do know that most of the modifications (bigger cams, high compression pistons, turbo) we do will increase cylinder pressures and running the higher octane fuel would not be a bad idea especially since the OEM knock sensor is pretty worthless if you even have one, let alone haven't disabled it.

When I had my old Civic LX (stock motor, D15B7) I would occassionally run 91 octane. It was like $1 more to fill my tank, so I figured "so what" since it supposedly has better additives and didn't have ethanol. Well, I noticed I got better gas mileage. Likely I was losing a little power since premium is harder to ignite, plus the lack of ethanol helped. I didn't care since it was just for driving to school and work and in the end, it was cheaper for me. I don't care that it wasn't needed, it worked to my advantage.

A lot of modern cars that the manual says require premium can run on regular. It's not that the car doesn't need it, the ECU will pull timing and dump in extra fuel to keep temps down and prevent knock. When you do this, you lose power. By running the proper fuel, you can make the power you should be able to.

 

For my 2000 SI the owner's manual and gas cap say 91. I read the shop service manual it says I have a knock sensor and the ECU will automatically adjust ignition timing to match the octane. Lately I've used 87 and can't tell any difference. There probably is a small HP loss but I can't actually feel it.

The ECU logic to perform this is probably pretty complex. I don't know about Honda but GM ECU's monitor fuel tank level and recognize when a fresh gas fill-up has occured. At that point the ECU assumes the driver used 91 and resets the timing tables. Then it listens to the knock sensor and adjusts as needed.

 

assuming both are straight gas, not the 87 having ethanol and the 91 being straight, etc, the 87 has a higher energy content than the 91.

 

x2

 

Weird, cuz my em1 says right on the gas cap and cluster premium gas only?

 

Some of the responses in this thread kill me, people think they know more than Honda!! To run lower octane the recommended from Honda, then say it's better, give me break. Go ahead, drive you high compression engines, and over the longer term, see what happens

 

B16A2s have semi high compression and a semi agressive timing curve. Use 91+ octane. You can use 87-89, but you get worse mileage because the ECU has to retard timing. You might also get a tiny bit of knock if you don't use premium.

 

Ran my b16 on 87 for a week and it ran like ****, went back to 93 and no problems.