well... i was wondering if higher octane really makes a difference. is there any reason to use 93 octane on a stock engine? would using 89 be the same as 93 for my pos 4gen? anyone want to solve this magical mystery to me?

 

it doesn't hurt, i use 93 octance myself, but as far as performance goes your not gonna notice it in a stock engine.

 

It gives you absolutely nothing for a stock engine, unless the compression ratio is higher than 10:1 on average, like H22s, B18Cs, B16Bs, K20A (type S) and TSX K24 (suffix I don't know). These engines will either absolutely require at least 91, or if they are equipped with a knock sensor, will work better with 91 octane.

 

no no no... im not asking for high performance reasons... im asking because i want to know if using 89 in my crappy f22a6 would be just as fine as using higher octane. i've been using 93 and 91 because i just THOUGHT it would be better for the old high milage engine, the question is... should i use 89 octane for my piece of crap or should i use something better.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by R3LL 1 &raquo;</TD></TR><TR><TD CLASS="quote">no no no... im not asking for high performance reasons... im asking because i want to know if using 89 in my crappy f22a6 would be just as fine as using higher octane. i've been using 93 and 91 because i just THOUGHT it would be better for the old high milage engine, the question is... should i use 89 octane for my piece of crap or should i use something better.</TD></TR></TABLE>

it doesnt really matter, but since the higher octane results in a more complete combustion i guess it would cut back on engine deposits.

 

With no engine knock, i'd use the cheapest gas availible on that car....

 

i wouldn't even waste my money on premium.... it does nothing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by booja &raquo;</TD></TR><TR><TD CLASS="quote">i wouldn't even waste my money on premium.... it does nothing</TD></TR></TABLE>

When you start messing with ignition timing and cam timing and upping the compression ratio it is a neccessity...

but for stock or just bolt ons don't throw your money away needlessly...

 

It's all about detonation... higher octane = less detonation = less engine damage.

If your car runs fine without any pinging, then you don't need any more octane.

One caveat...if you have a car with variable valve timing, then using lower octane MAY result in your engine retarding the timing a bit to compensate, and giving you less performance. In that case, using higher octane would improve performance.

Tom

 

unless you drive a 7th gen accord, higher Octane than the minimum required by honda is pointless. the 6th Gen V6 cars make LESS power on higher octane fuel...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TomSlick &raquo;</TD></TR><TR><TD CLASS="quote">It's all about detonation... higher octane = less detonation = less engine damage.

If your car runs fine without any pinging, then you don't need any more octane.

One caveat...if you have a car with variable valve timing, then using lower octane MAY result in your engine retarding the timing a bit to compensate, and giving you less performance. In that case, using higher octane would improve performance.

Tom</TD></TR></TABLE>

He's right. Two cars that can detect and advance/retard the timing automatically are the Mitsu Lancer Evo and I think the Subaru Impreza STi. 4th gen Accords won't detect different octane levels, so just run the recommended octane level unless you put in higher compression pistons or significantly advance the timing.

 

add the 7th gen accord engines to the list of cars that can make use of higher octane fuel

Both the K24 and J30A4

 

using 93 octane indirectly enhances your performance, here's how:

By paying for it you empty out your wallet faster, thereby giving you less weight and ultimately faster acceleration times.

 

i think my manual says 84 octane minimum (i've only seen 84 in mexico). these cars were designed to run on shitty gas... nuff said.

 

i heard that on f-series motors(except the f20c in the s2000), using higher octane gives worse gas mileage and performance. just stick with 87, the engine was designed to run off this.

 

Modified by CardDealer at 4:02 PM 11/17/2006

 

Kinda hard to believe that higher octane gas would produce lower fuel milage--not saying you're wrong, I just can't see why. Maybe there's something funky about the Honda engines?

In fact, ALL gas sold in the US has detergents/additives that are intended to clean injectors/carbs (really meant for the injectors though). The increase in octane is not generated via the additives, but by the relative ratios of the various fractions/distillates produced in the cracking process. There may be a slight difference in the cleaners added to a manufacturer's regular vs premium, but I don't think it's much--much likely a greater difference from company A to company B regular additives.

The only thing I can think of that would give you poorer milage is MTBE that's added to gas in some states in the winter months. This is documented to give reduced milage (not to mention cancers, headaches, etc.). But unless they put less MTBE in premium gas during those months, I don't see why there would be a milage penalty from use of premium.

Tom

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by schlit &raquo;</TD></TR><TR><TD CLASS="quote">The higher octane fuels have cleaning additives in them. That's the only way you will see an increase in power.....and the reason you cannot use high octane fuel in some marine engines.
</TD></TR></TABLE>

Hate to burst your bubble, but higher octane has nothing to do with the cleanliness of the gasoline.

As stated before, the octane rating of gasoline is simply it's resistance to detonation. Or in other words, how slow it burns. That's how it can make more power, but only if the ignition is tuned correctly (i.e., advanced correctly). I'm not going to get into the whole story of how combustion works, that can be found on the internet in many many places.

But cleanliness of the fuel just depends on where you get it and where they get it from.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TomSlick &raquo;</TD></TR><TR><TD CLASS="quote">
The only thing I can think of that would give you poorer milage is MTBE that's added to gas in some states in the winter months. This is documented to give reduced milage (not to mention cancers, headaches, etc.). But unless they put less MTBE in premium gas during those months, I don't see why there would be a milage penalty from use of premium.
</TD></TR></TABLE>

The reason you can LOSE mileage with a higher octane gasoline is because you'd be running a gasoline with a slower burn rate, that is, it takes longer for complete combustion of the fuel to take place. With a stock ECU, it doesn't know the difference between regular octane it was designed for and higher octane. So, what happens? The ecu doesn't advance the spark early enough in the compression stroke to accomodate for the extra time it takes to burn the fuel.
This results in lost gas mileage, as well as the possibilty of lost horsepower for the simple fact that the fuel wasn't used.

 

all I know is stay away from price club stale *** gasoline.....there's a reason you can get premium over there for the same price as exxon's or shell's regular octane.

 

Octane only helps if your car needs it. If it's not pinging/detonating on 87, it wont help (it'll hurt actually) to go higher. The higher the octane, the richer it'll run.

 

sorry newb question, wut is pinging ?
and where u guys get 93 octane gas ? the highest at gas station is 91

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ddua &raquo;</TD></TR><TR><TD CLASS="quote">sorry newb question, wut is pinging ?
and where u guys get 93 octane gas ? the highest at gas station is 91</TD></TR></TABLE>

cali does not get 93 anymore, you can thank your liberal *** gov't for that.

pinging or knocking is a noise made by the motor that can be heard usually when the car is lugging up a hill or under a load. you'll have to turn off your radio to hear it and it may not be heard if you have a loud exhaust.

basically follow what the car manufacturer says for gasoline type, anything else is a waste unless you modify your car to take advantage of better gas.

 

pinging = detonation = spontaneous combustion of fuel before the flame front = uncontrolled combustion = bad

 

pinging usually results from a very hot engine and usually is not a problem with newer model FI injected cars....the gas is so hot when it enters the chamber that it burns without a spark and is a quick way to kill an engine