using 84 octane for 1999 prelude is BAD?

[Cavaturbo]

hi, I have been using the 84 octane fuel on my 1999 prelude for a long while now......is that really bad to the engine? or the only negative about it is less smooth and lesser power? Thanks for the help.

[Cavaturbo]

opps I mean 87 octane not 84

[ricebike]

hmm, does it call for regular gas?

that vehicle has a knock sensor so it'll ~retard the timing to save your engine~ do you notice a loss of power?

try this, next time fill up w/ what the owner's manual stated & after about 50 cycles of on-off key turns, see if it makes a difference for you.

[Cavaturbo]

power-wise, I cant really tell the differences because i rarely rev the car pass 5000rpm. The thing I noticed might be a very very tiny ping sound if i the window is down and the engine is under load at low RPM. My concern is wether or not I am damaging my car by using a lower octane fuel then specified by the honda?

[Cavaturbo]

oh btw, this car requires 91 octane gas.

[ricebike]

hmm, i'm on a nissan~based forum most of the time, but the later models require 91 octane instead of 87...

soo if YOUstart feeling the pinging, then I would go back up to @ least mid-grade if you wanna stay on the cheap. & see if you still notice the pinging...

long term, i've heard it'll harm the engine since pinging = pre-detonation which is not good...

the fuel is exploding before the optimum stroke of the cylinder is reached...well, that's my guess anyways.

[J-Wat]

Well... you can use whatever you want in it but it comes at a price.

First off this is a high performance, high compression engine which is why 91 is required in the first place. In the event that 91 isn't available, 87 can be used but it is not a good idea to run it every tank. The computer will sense the knocking and retard the timing and also disable vtec.

It doesnt make sense to me why people do this. The tank holds 15.9 gal and premium is usually 20 cents more so youre saving 3 dollars. the use of regular also decreases your gas mileage so what you are saving by using regular you are using in lost gas mileage.

[lilwhitelude]

I agree, your gas miliage will go down. And performance will suffer. If you are getting any pinging, that isn't good. I have a 94 si h23. When I first bought the car, I filled up with regular. My gas miliage was around 16mpg or so. It took for me to open my gas door and see the PREMIEM FUEL ONLY sticker to realize what was going on. Pluse the fact that it sais it on my dash right under the speedometer.
You can always tell what kind of fuel you use when you pull the head off. Regular fuel in that engine will leave much carbon on the valve surface and in the combustion chamber surface of the head. That carbon reduces fuel burn during the combustion proccess. Better burn equalls better fuel economy and performance.. You will save money at the pump if you use 93..
lilwhitelude