im currently puttin in 93 octane.. will my car get messed up if i started to put 89 or 87 octane in it? like over an extended period of time, or if i alternate

 

you will deff feel lost in performance and might experience minor pinging.

 

i dont know what year you have but i have a 92si and if i put 89 car runs like absolute ****, even with 91 there is a noticable bogging, i'd stick with 93 for the few more cents you pay its worth it.

 

try some octane booster for fun. that **** is crazy.

 

i use octane booster and it does make a difference...

 

If your car asks for 91 or higher, then use 91 or higher. Almost all cars use four-stroke gasoline engines. One of the strokes is the compression stroke, where the engine compresses a cylinder-full of air and gas into a much smaller volume before igniting it with a spark plug. The amount of compression is called the compression ratio of the engine. A typical engine might have a compression ratio of 8-to-1.

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

 

i have a 94h22a1 and i only run 91+. i let my freind drive my car for awhile and wghen i got it back i knew right away that it wasnt running on 91 cause it sounded different and ran like crap. you can try octane booster but it doesnt do anything that i can tell i think it only bumps it up a point or two. if you wanna have fun put 104 (vp) in their and hold on. i did that one night at the street races and had a ball with it. just cost me 5.00 a gallon

 

i've added octane booster before and noticed no difference at all...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blackhorse6 &raquo;</TD></TR><TR><TD CLASS="quote">If your car asks for 91 or higher, then use 91 or higher. Almost all cars use four-stroke gasoline engines. One of the strokes is the compression stroke, where the engine compresses a cylinder-full of air and gas into a much smaller volume before igniting it with a spark plug. The amount of compression is called the compression ratio of the engine. A typical engine might have a compression ratio of 8-to-1.

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

</TD></TR></TABLE>
what would u use on boosted h22 with 8.3:1 compression?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelude994e &raquo;</TD></TR><TR><TD CLASS="quote">what would u use on boosted h22 with 8.3:1 compression?</TD></TR></TABLE>

uh, whatever octane your tuner tuned your engine for, which is probably 91+.

if it's untuned, stick with 91+ since untuned turbos have a tendency to be hand grenades if you're using lower octane...