Is the higher octane of gas you use, the slower it will burn and will release less toxic gas into the air?

Question

So is this basically means that octane 93 will be the cleanest for the air compare to octane 87

Answer 1

Octane rating has nothing to do with the amount of pollution produced. Octane measure the anti-knocking capacity of the fuel, that is its capability to avoid auto-ignition under high compression.
If you have an engine meant to burn, say, 87 RON, putting 93 RON in it will achieve NOTHING at all except costing more. In cars, there often are knock sensors that will change the ignition advance or alter the air-fuel mix to avoid the problem, so a car meant for high octane could work with lower octane fuel by running rich, which of course means burning a bit more gas for the same power, thereby producing a bit more pollution as a result.
That said, having a high octane rating allows an engine to run lean (by the way and for the record, motorcar engines have better electronic ignition control than general aviation piston engine powered airplane. The general aviation is actually forced to extreme conservatism by the threat of lawsuits and liability risks, and most airplane piston engine do not have any electronic control at all, and use carburator instead of injection, as silly as this may sound, but I digress) and a lean engine will typically run at a higher temperature, and high temperatures are more likely to make the nitrogen -- which still makes 78% of the air -- react and produce nitrous oxides, so in actual fact, an engine that is meant for high octane fuel AND does not have catalytic converter will release proportionally more pollution in the form of nitrous oxides than an engine of equal power with a lower compression.
Sorry if this sounds quite complex; well it is, that is why we aerospace engineers have to go though all that curriculum...

Answer 2

I don't beleive that octane has much to do with pollution. The cleanest burns should only release carbon dioxide and water. As you know cars and airplanes don't release only CO2 and H20. Since you have this question under the airplane category you should know that piston powered airplanes (i.e. those with propellors that aren't turboprops) usually use a type of fuel called 100LL. This stands for 100 octane, low lead. So, even though this fuel is 100 octane (because of the lead added it has a much higher octane than what you would put in your car, but other than that it is basically the same fuel) and yet it will still release some harmfull pollutants (such as carbon monoxide, and lead).

Answer 3

Octane ratings are achieved through refining (additives,etc.). As for the burning, well who ever stuck their head inside a cylinder. I believe once ignited they all burn roughly the same...HOT and FAST! lol.... ok, the difference is knock characteristics. Once compressed to a certain point, fuel ignites w/o an ignition source (spark). Higher the octane the less tendecy to pre-maturely ignite. This is why ppl always take the suggested "fill it up with 93,super." I believe ppl do this for reasons of assuming more cost better fuel...in part true. Most this suggestion is due to the larger amount of 4 cylinders on the road which are primarily made of aluminum, which is easily damaged by pre-ignition. Cylinders firing early will damage the engine!

Answer 4

Uuuuh, i don't really know that that would be the case, Ive never heard that octane affects pollution, when burning, the higher the octane, the lower the temp that is reached when burning, thats why when you modify your car like drag racers, or even highly modified sports cars, you use higher octane because with all of the modifications your engine runs at a way higher temp. Running high octane like 93 or even race fuels that are like 99octane will keep the temp at a containable level.

Answer 5

No, the higher octane fuel uses a nasty cocktail of chemicals to raise its knock resistance, far nastier than the lead they used to use, so all in all the lower the octane the afer the fuel.
Seriously for real world use water injection is as good an antiknock remedy as any it just needs ceramic coatings and stainless steel exhausts, not to mention clean awater and effective filters, to allow its use in mass market vehicles, then we could have high compression Turbocharged 800cc 3 cylinder engines poking out 200 bhp and using 87 octane fuel while returning diesel like 50mpg on the motorway with greatly reduced toxic emissions.

Answer 6

It ignites faster burns hotter and puts more pollutants in the air because of the extra chemicals they add during refining to make it higher octane.

Answer 7

Higher octane fuel does burn slower and more evenly, but I don't think it has an effect on emissions. (Other than leaded gas, jet fuel, and diesel, which add considerably to emissions).

All hydrocarbon based fuels release H2O, CO2, CO and NOX. It is the design of the engine, how you use it, and emmisions control devices that determine how many toxic fumes enter the atmosphere.

High octane fuels (below 100) just use octane, a fraction of crude.

And water injection is terrible for emmisions, take a look:

http://www1.airliners.net/open.file?id=0489691&WxsIERv=Obrvat%20XP-135D%20Fgengbgnaxre%20%28717-148%29&Wm=0&WdsYXMg=HFN%20-%20Nve%20Sbepr&QtODMg=Zvyqraunyy%20%28ZUM%20%2F%20TKU%20%2F%20RTHA%29&ERDLTkt=HX%20-%20Ratynaq&ktODMp=Nhthfg%201987&BP=1&WNEb25u=Senax%20P.%20Qhnegr%20We.&xsIERvdWdsY=58-0094&MgTUQtODMgKE=Bcrengrq%20ol%20Qrg%204%2F9%20FEJ%2C%20Ornyr%20NSO%2C%20PN.%20N%20urnil%20XP-135D%20vf%20frra%20va%20n%20jngre-vawrpgvba%20gnxr-bss.%20Fur%20jvyy%20ershry%20na%20FE-71N%20Oynpxoveq%20jvgu%20guvpx%20WC-7%20wrgshry.&YXMgTUQtODMgKERD=3829&NEb25uZWxs=2004-01-15%2000%3A00%3A00&ODJ9dvCE=&O89Dcjdg=17839&static=yes&width=1024&height=692&sok=JURER%20%20%28ZNGPU%20%28nvepensg%2Cnveyvar%2Ccynpr%2Ccubgb_qngr%2Cpbhagel%2Cerznex%2Ccubgbtencure%2Crznvy%2Clrne%2Cert%2Cnvepensg_trarevp%2Cpa%2Cpbqr%29%20NTNVAFG%20%28%27%2B%22jngre%22%20%2B%22vawrpgvba%22%27%20VA%20OBBYRNA%20ZBQR%29%29%20%20BEQRE%20OL%20cubgb_vq%20QRFP&photo_nr=5&prev_id=0507765&next_id=0413044&size=L

Answer 8

No, actually the higher octain fuels have more additives. See Wikidpedia

Answer 9

nope