Everett...

I used a couple gallons of xylene in a 3/4 full tank. It caused the check engine light to come on. I had the dealer run the codes and it was the O2 sensors picking up the higher octane. I have read a couple of articles since then on toluene and that sounds like the thing to use...I have read nothing on xylene...other than what I have seen in this thread. I am going to run this tank out (the check engine light did go out by the way...when I deluded the mix) and try a gallon of toluene to a full tank of gas. I did notice a difference in performance with the xylene...just not comfortable with the limited data on it.

 

Branden:

Thanks.

The next question would be what octane rating is best used for everyday street use? 104?

If that's the case, assuming a bone dry 18.5 gallon tank and 92 octane pump gas, you'd need 8.88 gallons of Toluene (117 octane) and 9.62 gallons of pump gas (92 octane) to get to a total of 104.

I'm *real* interested in this since I dyno'd my car last Saturday and at about 5,250 rpm you can see the graph start to ripple as the A/F ratio drops to about 11.2. The people at Speed Works suggested I switch from platinum plugs to TR55's with aftermarket wires, and use a thermostat that opens sooner.

I can see where cooler temperatures would reduce or eliminate the knock. I have the plugs and will put them in this weekend. I'm not going to do the wires as I don't think they'll make much, if any, difference. I'll also do the thermostat.

Another forum member was there getting a NOS bottle refilled and he said that the Toluene would eliminate it as well, but I failed to find out how much to add to a tank of gas. Shooting for a specific octane rating seems to make more sense, I just don't want to screw something up.

Thanks.

Everett

 

Use the stuff that LAPD sells. Lowest cost and it works.

 

Everett...

I am not smart enough to figure out the best octane level. As I mentioned, I added 2 gallons of xylene to about 13-14 gallons of 93 octane gas and my check engine light went off...it was just the O2 sensors, which was no big deal. My plan is to start with one gallon of toluene to 17 gallons of gas and see how the car reacts. I will gradually increase it by a gallon at each fill up. I have seen mixed emotions about the octane ratings on this and other threads from our members. I think you have to experiment a little and see what works best for your machine. When your check engine light comes on, or your car doesn't run as good...you know to back off on the toluene. Here is a really good site to check out to follow up on the toluene mix...http://home.kscable.com/ssutton/miata/engine/toluene.html. Lots of good info on toluene. Good luck pardoner...

 

Everett...

Check out my thread "Xylene and other octane boosters"...there is some more good info there. Plus more web sites to reference regarding octane and other boosters...to include toluene.

;)

 

Hmmm... That does make a lot of sense.

Economically is breaks down to about $3.45 a gallon (based on California prices). The 100 Octane is avaliable at a few rare pumps in the SF Bay Area at about $4+ per gallon. So, either way it is a close call and becomes a manner of safety and easy access.

I certainly am thinking about trying one and then the other to see what the results are.

In the meantime I have added in the 104 Octane boost and seem a fair difference in performance and a definate difference in how smooth the Engine runs (darn California gas).

:cheers:

 

it is possible the Xylene caused your MIL light; O2 sensors may have 'confused' the strange exhaust chemistry. do you have Atap or ScanEase? pull your code to see what's up. this will not hurt your engine or sensors.all tht i have read of xylene and toluene indicate that the 2 are so dam close to each othe chemically that they're nearly one and the same. someone else asked further up what are acceptable ratio's. First off, Xylene and Toluene are so close to eachother that Xylene is 116 and Toluene is 117 octane. using either one will not benefit you more than the other IMO. i've used both with similar results. DO NOT RUN PURE XYLENE OR TOLUENE. yes, you'd have 117 octane, but, running this straight is not so good becuase this 'solvent' lacks critical additives/lubricants. Formula 1 race cars have experimented with this and have found the need to add a lubricant. i've heard of adding ATF, Mystery Oil, etc will provide the needed lubricant. anyway, if you stay at a 2:1 ratio (33% xylene) you are surely safe. you can change your ratios further to effect a higher octane, BUT, keep in mind, you are gaining nothing if you do not really need the higher octane to fight knock. Branden Mardis has the right idea...try different mixtures to determine at which octane level your knock goes away, go 1 or 2 more octane points and your done. if that ends up being only 95 octane, GREAT1 stick with it. that is the whole purpose of octane is to fight knock. good luck and have fun!!!


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