Toluene and Xylene

I'm not planning on using xylene but I wanted to start a discussion on more of technical what if...

If you're unfamiliar with them, Xylene has a 118 octane rating where as Toluene is 121[1]. They are found in crude oil but are removed in the refining process. You can still buy Xylene from hardware store. Not sure about Toluene.

I recall xylene being used in F1 many years ago but was banned at some point. There is a ton of material online talking about it being safe for cars (not safe for people) but most of this info is out dated. How might these hydrocarbons work in modern engines? What seals/sensors could they hurt?

1. https://en.m.wikipedia.org/wiki/Octane_rating

 

Your health is more important than your truck.

 

I agree 100%. As I said before, it's "not safe for people". I'm not interested in putting this in my truck. I'm purly interested in a technical discussion on the vehicle itself.

 

as a young retired chemical engineer i tell you one thing. toyota design this engine on 91 octane, so anything more is a waste due to its engine inefficiency. in theory higher octane burns hotter=>higher energy=>more power, but it is not in practice or somebody has to pay a lot for an almost perfectly designed engine. as always i hope some body gives you a better technical discussion on your interested.

 

Sorry, but that is absolutely incorrect and you should know that if you are a chem engineer. Higher octane actually burns slower, allowing higher compression and more ignition timing - both of those raising the HP of the engine. But if you take an engine with 87 octane and dyno it, and change nothing but the gas to 93 octane and dyno it again, you will see zero increase in HP. None. If you'd like technical references I can easily provide them.

 

Please do! I posted this under the technical discussion for this exact reason. I haven't looked them up but I'm assuming the specific energy of each differs from regular pump gas.

 

Xylene and toluene dissolve polymers with a vengeance, including the otherwise chemical resistant rubber in fuel hoses. Use with caution. You'll want to rinse it down with some fresh gas if you add it to the tank - which I personally would not do.

 

Do it... for SCIENCE!!

 

Just use this !!!

https://vpracingfuels.com/vp-street-legal-fuel/

 

Both are excellent as degreaser for ALL metal parts. Toluene > Xylene. Wouldn't run either I my stock engine tho. Totally destroy anything plasticky or rubbery..(pretty sure those are both real words)

 

Fixed that for you

 

you are right to a certain degree because what you know is from what you read, just like 1+1=2. Most importantly you did not know how to analyze my short summary or i did not make it clear.

op wants to talk about tacoma engine. so what i said in theory and in practice about this engine. you can only gain hp if you alter this engine configurations, not by fuel itself. a super charger would do it nicely.

i worked on nuclear fuel and know nothing about how engine works. but i know one thing that high octane fuel use for jet/race car engines since these engines require rapid reaction in their chambers to produce hp for their specific designed engines. you can put this fuel in tacoma, but it won't do a thing.

do you ever wonder what fuel rockets use for it engines?. do you know why diesel engines run more efficient than gas engines?

if you have one or more courses in thermodynamic(caution: many students drop out) , you will change the way you think about what you read or how you analyze what you read. keep in mind that knowledge from references is limited since you don't have the ability to analyze it. and so marketing has always been misleading consumers(a caution only).

nobody can change the physic of thermodynamic if he/she doesn't change/alter the engine.

 

That is the exact opposite of what happens and why high octane fuel is used in race engines. And why are you throwing in jet fuel (kerosene) into the mix? Totally inapplicable. So I guess you are right, and every tech article written is wrong? LOL.

 

Dragsters use methanol. I'd start there.

 

I know thermodynamics - Heck, I've learned it dozens of times!

 

nice -- Even Batman gets cranky about his heat transfer class

 

Way back in 1921, they discovered this thing called Tetraethyl Lead was a way to increase the octane of gasoline. It's been banned here for decades but is still used in a few countries. This is just as good for people as toluene and xylene.

Plastic model glue often contains xylene and toluene. it uses these solvents to melt the plastic in order to bond it together. Sounds like they would both do wonders for the plastic and rubber components of your truck's fuel system.

 

Found this:

-- https://www.modularfords.com/threads/111987-Stoichiometry-of-gasoline-toluene

 

Despite his lack of communications skills, he is actually correct, in that higher octane fuels, *in theory* are composed of longer carbon chains, which means more chemical bonds, which means that they store more chemical energy. More energy means more heat from combustion. His point about diesel engines being more efficient is a roundabout way of explaining this, in that the fuel actually stores about 30% more chemical energy than gasoline. In other words, it takes less fuel to output the same amount of energy and perform the same amount of work.

In the case of a chemical powered engine, energy is in the form of heat. Hot gases expand and push down on pistons. The heat is provided by the chemical reaction -- combustion.

Now the reason why he uses the words "in theory" is because there is no appreciable difference in the amount of energy stored in different octane GRADES of gasoline. It doesn't matter if its 87 or 95, it has the same amount of energy. In the higher numbers, they add a combustion inhibitor to raise the ignition temperature, in order to withstand higher levels of compression (because when you compress a gas, it becomes HOT, compress it more, it gets more hot). This also raises another point, in that the use of the term OCTANE is really quite a bad choice for describing the level of combustion inhibition. The word "octane" actually describes a very specific molecule: C8H18. Each carbon atom can form 4 chemical bonds. There are 8 carbon atoms, each linked through a single bond in-line to the next carbon, so two bonds of each carbon are used to connect to the two carbon atoms each side of it, except the two carbons on the ends of the chain, which only use 1. Each remaining bond on each carbon atom is connected to a hydrogen atom, which means 2 hydrogen atoms to each carbon, except for the two end carbons, which each get 3 hydrogens.

So here is the thing; the longer chain requires more heat to ignite, but *also* releases more heat when it combusts. But remember that is only *if* it is *actually* a longer chain.