I got into a talk with someone and came to a stalemate regarding this topic. Everyone should know by now that those over the counter octane boost in a bottle are overpriced and may or may not increase the octane rating of the fuel significantly to make a huge difference.

However when mixing your fuels, it's either Xylene or Toluene that's added however we can't seem to agree on whether it's necessary to also add in MMO (marvel mystery oil) to add some top cylinder lubrication. The person I got into an argument with says that it's mandatory to have MMO in there, however when I talked to my friend who's also a chemist that works at a local Chevron refinery, he informed me that they usually add in generous amounts of lubricants into the final mix of fuel since their product has to accommodate a wide range of vehicle applications, so he felt it wasn't necessary to add more.

What do you guys think?

 

Sorry but you lost me at Xylene. What can I say, I'm no chemist.

 

Xylene and Toluene are solvent products you can find at your local paint supply store.

Is it true they can strip the tank linings and ruin rubber hoses?

 

Xylene and Toluene are chemicals that fuel companies often add in order to raise/improve the octane rating of the fuel. Xylene will improve the antiknock properties of gasoline slightly better than Toluene will. As such most homebrewers go with Xylene since you get more for the quantity you use. I use Toluene (because it was $2/gallon cheaper than Xylene at the time) to achieve a relative 94-95 octane rating to manage my Mugen ECU in our region. I know of many WRX/STI/Evo folks that also homebrew their own fuels in order to be able to make use of their mods effectively.

slipper is right, both are strong solvents and if used in huge quantities I'm certain there's going to be some negative impact but I don't forsee anyone that'd use those kinds of levels anyhow, especially on a street-driven car.

In a race car it might be different since having its life is limited to track-only use may involve having a race-only motor tuned to use much more aggressive ignition and compression, boost, higher engine temps, not to forget the raw endurance level of being at a higher output level for a larger portion of the time. As such this type of special application might call for nothing short of 100 octane fuels to be used, thus higher levels of antiknock additives in the fuel such as Xylene/Toluene might be used, assuming they're not already using race-ready "store bought" fuel, not homebrew.

 

Again (sorry to get off topic), but the argument is whether homebrew needs MMO as a lubricant. I did a search on the web and I've found conflicting comments pointing in either direction.