What Octane level U guys use

[Joemama]

I seen in Iowa, they have 89.5, 91.5, and 93.5 and so on, they have ethal in the gas. Does this hurt the engine in any way?<P> I used it when I was going to Nebraska and it seemed to give my engine a little rattle to it. The mazda Dealer sold me this silver round can for $20 to clean it out. It worked but its Expensive!! its somethin like CD-2 or somethin. Cant find it in the autoparts stores,

[pelado]

Mazdamaniac, I have only one point to make - all of the major producers (Shell, Chevron, Texaco) have their own refineries, take a drive through southeast Texas some time and see. All of the other gas stations must buy their gas from them.<P>Joemama, I vaguely recall reading something about ethanol laced gas can deterioate rubber hoses over time but I'm not certain about that.<P>The basic answer to octane requirements is that if your engine doesn't ping with it, then its OK. Octane doesn't enhance gasoline's energy content, it just keeps it from knocking/pinging.<P>I read an article in CycleWorld that told how they rate octane in gas. The lab has a one cylinder engine where the cylinder can be moved up or down with the engine running. They keep increasing the compression ratio by moving the cylinder down until it knocks and then they compare that CR to an established standard to determine the octane rating for that gasoline. The octane rating has no units, e.g. btu/lbm, its just a number.<P>Some years ago in Formula 1 the teams were getting custom gas formulations that made more power but they weren't messing with octane (can't recall what it was) and the gas was over $100 a gallon! This was later outlawed by the FIA to hold down costs.

[David Coleman]

The fuel you speak of is likely Toluene. The 2nd T in TNT. I've actually played with a few hundred mils of it in a lab setting [lab Prof obviously didn't know I was...]. It's pretty neat stuff, and from what I hear from the MKIV guys, you can get some from Paint supply stores by the gallon. From my experiments, It burned cool and long per unit of volume. Pretty neato stuff. I think someone mentioned Xylene as another octane booster, but that's for forced induction and not Low compression, Alum head, mild cammed street motors like the K8D. I have had the best track times with 89 octane and a reset factory computer. My times with 93 octane were consistently 1-2 tenths slower. I run 87 on the street, cause I'm poor, and it's not worth the extra .5bhp, when I can out drive somebody and save my cash.

[mazdamaniac]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><STRONG>Mazdamaniac, I have only one point to make - all of the major producers (Shell, Chevron, Texaco) have their own refineries, take a drive through southeast Texas some time and see. All of the other gas stations must buy their gas from them.<BR></STRONG><HR></BLOCKQUOTE><P>They all operate refineries, but they share base stock.<BR>There are many steps in the "refining" of gasoline, but the main funtion of these refineries is blending and fulfilment.