i have an h22a1 motor, is it okay to sometimes put 89 in my tank? ive always put 91 or 93..but im just wondering with all the high gas prices if it would hurt.. this is probably a stupid question.

 

There's a reason your owner's manual says "Premium Unleaded Fuel Only". Mixing a little mid-grade in there shouldn't be a huge deal, but I know I definitely could tell a difference if I filled up with 87. Then again I have slightly lower compression than you since I have H23/vtec setup so you might be have more of a (negative) response with mid-grade than I.

Higher octane just translates to more resistance to detonation. The lower you go in fuel grade on a higher compression engine, the more you will have early detonation (pinging) which over time could really F things up.

 

thanks for your help, i think im just gonna stick with the premium haha, i dont need anymore problems with my car.

 

Yeah, I definitely don't like spending $35-$40 filling up my Honda either.....just doesn't seem right. I'm getting 26-32 mpg, so just keep trying to tell myself that.

 

yeahh.. thats about the same for me. i just drive all over the place and i feel like im constantly filling up and my car mileage is going too high.. im at 143k right now, i bought my car at 93k three years ago.but whatever i sure it'll be fine.

 

143k on a honda is nothing, you still have awhile to go.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lewdin’ Incognito &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, I definitely don't like spending $35-$40 filling up my Honda either.....just doesn't seem right. </TD></TR></TABLE>

Well...that's a bargain for us. In my country I pay at least 70 euro's (about 90 usd) for filling it up.

That's what I call love for the prelude

 

I got 172k on mine.. seems like I'm getting about 20-25 mpg. I use VTEC almost every time I go out. Kinda sucks having to use premium but I don't dare use anything else.

 

i have run 87 100s of times in my h22. IF and I mean IF the engine knocks at all which I highly doubt then all it will do its pull alittle timing and add fuel. and that is only for 1 driving session. I have never heard my lude knock on 87

 

So you're going to save 10 cents a gallon to use mid grade? That comes out to about $1.50 if you get fifteen gallons. Just go with premium, that way your motor won't retard your timing and gunk **** up, and not go into vtec for you.

 

i always used midgrade, you guys think it'd be wise to start fillling it with premium?

 

Are you serious?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">i have run 87 100s of times in my h22. IF and I mean IF the engine knocks at all which I highly doubt then all it will do its pull alittle timing and add fuel. and that is only for 1 driving session. I have never heard my lude knock on 87</TD></TR></TABLE>

its pretty funny that you say you never hear it when it often occurs below the threshold of hearing. Plus the commonly accepted idea that the knock sensor is turned off after 5k rpm as well. I take it that dyno charts showing knock occurring, but never heard by the operator are not real?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">
I take it that dyno charts showing knock occurring, but never heard by the operator are not real?</TD></TR></TABLE>

you are correct

no, but seriously, I have driven many many vehicles in my time and any time i get some bad gas or i am runing a low grade fuel in a HIGH compression motor i can physically hear it knocking, and that is the sever knock one should be worried about. Of course on Forced induction motors an knock is bad and often yes preignition can't be heard by the ear. 10:1 isn't high compression in my book, keep in mind knock on a FI motor can do much more damage because of the higher cylinder presures, n/a is usually a different story.


even if the car does knock the ecu will adjust for it, I was just answering the question saying that its perfectly safe to use lower grade fuel. If you always want to buy 91 or 93 octane thats fine too.

 

Running gas your car is not tuned for may very well be more expensive in the long run.

Your ecu is expecting a certain detonation rating, and won't like it when it's not getting what it expects.

Early h22's don't have knock sensors, so don't run lower grade fuel unless you retard your timing.

Chances are, you'll spend less per gallon, but get less MPG from lower grade fuel when your ecu is wanting premium.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AaronW &raquo;</TD></TR><TR><TD CLASS="quote">
Early h22's don't have knock sensors, so don't run lower grade fuel unless you retard your timing.
</TD></TR></TABLE>

I am only going to be nice because i like your avatar , but EVERY h22 i have ever seen has had a knock sensor. The only year h22 that i haven't physically seen is the first h22 released in japen in like 91. but every usdm model has one as far as i know.

 

thanks for all your advice! im just gonna stick with the 91 and 93

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AaronW &raquo;</TD></TR><TR><TD CLASS="quote">Running gas your car is not tuned for may very well be more expensive in the long run.

Your ecu is expecting a certain detonation rating, and won't like it when it's not getting what it expects.

Early h22's don't have knock sensors, so don't run lower grade fuel unless you retard your timing.

Chances are, you'll spend less per gallon, but get less MPG from lower grade fuel when your ecu is wanting premium.</TD></TR></TABLE>

the ecu expects detonation? what?