What octane is best, and why

[PissRev]

But now I just burn any non-ethanol I can get. It's either 87 or 90 octane.

 

[Bull Mountains]

Any of you guys remember the old Amoco white gas? That's what I used to burn in all my two strokes until Amoco was bought out by BP. As a kid, there was a clear window in the gas pump and you could see that the gas was as clear as water.

I dont remember that, but I will mention that CAT cracker gas and alky gas are crystal clear. Most of the yellowish tints to gasoline comes from poorer quality streams and adulteration with diesel fuel.

 

[PissRev]

I dont remember that, but I will mention that CAT cracker gas and alky gas are crystal clear. Most of the yellowish tints to gasoline comes from poorer quality streams and adulteration with diesel fuel.

Here's an article from 1992 about this.
https://www.google.com/amp/s/www.chicagotribune.com/news/ct-xpm-1992-09-01-9203190796-story,amp.html

 

[davidwyby]

I have a couple gallons of CA ethanol 87 pump gas that’s around 3 months old. The container often offgasses from the heat in the desert summer and traveling up and down the mountains. What do we lose in the off gassing? I’m assuming the good stuff…?
Thanks

 

[Duane(Pa)]

VOC’s I bet... @Kiwioilboiler can you help here?

 

[Kiwioilboiler]

VOC’s I bet... @Kiwioilboiler can you help here?

Pretty much D Wayne. We just call them 'the light ends'.
If the container is sealed the expansion of gases should mostly remain in the container.

https://www.garden-kit.co.uk/products/aspen-fuel/why-petrol-goes-stale

 

[davidwyby]

So if my unvented plastic fuel can has bulged and I've let the "light ends" out a few times over the summer, performance will be degraded. I will compare to some fresh gas and some VP/Trufuel.

 

[pbillyi69]

so where i live e/free gas is 92 at the pump and $5.50 a gal, there is one place way far outside of the city has e/free 87 for 5 a gal or more and you have to drive 20 miles out and 20 miles back to get it. there is a small airport near by that has 100ll for 4.50 gal and then there is just plain pump gas everywhers for various prices. or the little cans of e/free gas which is about 25 a gal at the hardware stores. so of the choices why or why not the 100ll avgas its the cheapest e/free gas of them all

 

[davidwyby]

I tried some VP tonight and didn’t notice anything earth shattering

 

[davidwyby]

so where i live e/free gas is 92 at the pump and $5.50 a gal, there is one place way far outside of the city has e/free 87 for 5 a gal or more and you have to drive 20 miles out and 20 miles back to get it. there is a small airport near by that has 100ll for 4.50 gal and then there is just plain pump gas everywhers for various prices. or the little cans of e/free gas which is about 25 a gal at the hardware stores. so of the choices why or why not the 100ll avgas its the cheapest e/free gas of them all

Too much octane

 

[Rogee]

Pretty much D Wayne. We just call them 'the light ends'.
If the container is sealed the expansion of gases should mostly remain in the container.

https://www.garden-kit.co.uk/products/aspen-fuel/why-petrol-goes-stale

So in nz I'm wasting my money buying the 100 octane, just stick with 91 is what's being said

 

[Kiwioilboiler]

So in nz I'm wasting my money buying the 100 octane, just stick with 91 is what's being said

What do you put 100 RON in mate?

 

[Woodwater]

Here i only can get 95, 98 and 100+, the lowest octane gas here is in the Stihl Motomix wich have 93 i have read.

 

[Kiwioilboiler]

Here i only can get 95, 98 and 100+, the lowest octane gas here is in the Stihl Motomix wich have 93 i have read.

There are different ways of quoting octane and it affects the 'number'.
RON MON AKI, check which applies in your country for me Markus if you would please.

 

[Woodwater]

There are different ways of quoting octane and it affects the 'number'.
RON MON AKI, check which applies in your country for me Markus if you would please.

RON

 

[Maintenance Chief]

I tried some VP tonight and didn’t notice anything earth shattering

You shouldn't notice anything for dozens of tanks, later on down the road the exhaust port "not" carboned up or the plug "not" being black with particulates and fouled. The canned gas should be categorized as what it doesn't have in it.
I don't use canned gas unless I find it on sale .

 

[Kiwioilboiler]

RON

Same as us then Markus, although no pump 100 here except aviation. Interesting that you have no 'Regular or 91' option. European cars tend to 95 tho ay.

 

[Woodwater]

years ago, they have banned 91 from the Gas Stations.

 

[Woodwater]

so a short research in the web and Wikipedia says that 95 RON here is in the USA listed mostly as 90 AON. The 91 RON we had here was the 86,75 AON.

learned something again.

 

[Hinerman]

so where i live e/free gas is 92 at the pump and $5.50 a gal, there is one place way far outside of the city has e/free 87 for 5 a gal or more and you have to drive 20 miles out and 20 miles back to get it. there is a small airport near by that has 100ll for 4.50 gal and then there is just plain pump gas everywhers for various prices. or the little cans of e/free gas which is about 25 a gal at the hardware stores. so of the choices why or why not the 100ll avgas its the cheapest e/free gas of them all

$5 and $5.50 per gallon!!!!! Seriously??? That is nuts imo.