93 bp/amoco oct gas vs off brand 92 oct vs Av gass...jetting same?

[masterblaster]

Ive read bp amoco has the best 93 oct gas,Shell close second.wonder how much diff in performance these net vs the cheapy off brand stations like citgo and the like.Ive gotten much worse milage in my truck with these cheap fuels,they only rate them at the pump at 92 oct here.
Av100 isnt much more $,Im sure it nets better HP on high comp and slight advance timing. Will jetting ideally be the same for switching between 93 oct and av 100? what % of power aprox would be picked up in a 185 to 190 psi 2 deg static advanced motor?

 

[Waternut]

There are a lot of questions there that I can't fully answer but here's what I do know... Generally the differences between exxon, bp, walmart, and all the other gas stations is the type/quality of additives. Some additives gunk up injectors, valves, etc. while other additives supposedly clean them. Some swear there is a difference. However, cars are easily running 200k-300k miles on whatever gas is cheapest these days without any adverse effects. If 200k miles isn't enough to notice a difference, I find it hard to believe there really is. I also doubt there is really enough difference between 92 and 93 octane unless you're running on the ragged edge of detonation.

Do some more research on Av gas though. It's not the same thing as 100 octane race fuel. It's a different composition and is a lighter fuel. If your engine is setup perfectly to run av gas, you might see some extra power and you might see some extra power running e85 too but it probably won't be enough to justify the extra hassle associated with obtaining either fuel.

 

[Pro-pulsion]

I did a little write-up on pump fuels awhile ago and the real thing to consider is if there is ethanol in the fuel. As far as I know, right now most stations only add in ethanol to 87 and 89 octane rated fuels. But make sure you know if the 92+ octanes have it in there. There are several things to worry about with ethanol but the most important are these...

1. it has been for years and still is being used in paint thinners
2. paint thinners break down oil and lubricating capabilities which could result in lean seizure
3. ethanol absorbs water reducing the octane rating by literally being watered down and creating a condition known as phase separation (phase separation is when you see what looks like a layer of separated water in the bottom of the tank)
4. water remover chemicals can't get rid of phase separated fuel, the tank has to be drained and dried or vacuumed out as much as possible (that's why all fuel stations have to do water tests regularly with their in-ground tanks)

Aside from that, all fuels are oxygenated which means oxygen has been added to help with reducing emissions. Due to the added oxygen, going larger on the jetting is a must to compensate for the leaner oxygenated fuel. So if it were me, I would drop in the second largest jetting you can get for the carb and try it before toying with higher than pump rated octane. Generally though, from the experience of many others I have talked to, anything a little higher than 180psi compression needs a high quality octane booster or a mix of AV and pump fuel.

 

[Aircraftsalz]

I like to run av gas 100LL, lots of benefits to av-gas. Both my SJ & Blaster have 180-190 PSI & run on 50/50 mix of 93 & 100LL with no change in jet size. My SJ with the Xscream 860 runs on straight avgas & TL. You can't go wrong with av gas, it burns a lot cleaner than auto fuel. I have disassembled aircraft engines that the owner has ran auto fuel & more internal parts had to be replaced, where engines ran only on avgas most of the internal parts pasted for another run. Just my .02 cents.

Go Blue (Avgas "100LL" is Blue)

 

[BombThreat]

whats av gas running per gallon now a days?

 

[Freakrider]

whats av gas running per gallon now a days?

near Tampa... super-ski states it's $4.....

 

[Aircraftsalz]

whats av gas running per gallon now a days?

At my county ran airport its $3.65 (This guy rips us off), 10 miles down the road its $2.69! I think the average is $4.00 per gal. It don't sound like much until your buying 100-150 gallons! LOL I make the 5 minute flight when filling up my planes.

 

[Waternut]

If you do go the av gas route, I would suggest calling your local airstrip and make sure they will sell you av gas. Some airports will allow you to put av gas in containers and some will only let you put it in a plane. I almost went that route when I got a head that produced roughly 190-195psi. One south of me (20 minutes away) will let anyone fill up. The lake is north of me and that airport won't even let you near the pump. I decided it was too much effort to deal with all of that crap so I was going to pay for race fuel and that company didn't like to open their shop during their own business hours. I eventually gave in and ran a good octane booster (if such a term exists) with 93 pump gas. I ran less and less octane booster monitoring for deto until I wasn't running any and it turned out ok.

 

[masterblaster]

I do know that most airports will let you fill whatever you like,that one must have had a issue in the past?
Aircraftsales.. I know av100 has lead in it so that would help a good bit for lubrication.not sure if it contains detergent additives,but I know it is HEAVILY govt mandated and is the same everywhere,no fudging allowed with this fuel,no one wants planes dropping out of the air.
As far as pump fuel I know all stations get their fuel from the same depos,with the exception of bp 93 oct.they refine this in their own plant. All other brands just add their unique additives,for keeping down deposits mainly in the valves,so no matter with 2 strokes.But I believe with what ive read and the mileage diff to cheap gas,Ive heard they add extra chemical additives that are much cheaper than gas that effect the oct even in premium fuels.Im almost positive all brands in all oct ratings including premium 93 has 10% eth.Race fuel or av100 is the only way to get away from this.
I dont enjoy the inconvenience of having to go out of my way or pay more for any kind of gas,but we have found a source for about the price listed above 2.80 a gall for av100. Im thinking on getting a 55 gallon drum and keeping it at the house and pumping it direct in my skis as I need it.Since its only 50cents more than our local 93 oct anyway.

 

[Aircraftsalz]

I think you would like AV Gas, no Ethenol crap! Like you said its the same every where you buy it. (I make money when planes fall out of the sky, I also get what gas is left!)LOL I work at the airport so its no problem to get 100LL, just the airport manger likes to charge us $1.00 more than other local airports. I buy 3-400 gallons a month from the local airport. I'm thinking about filling a 55 gallon drum to save a few bucks.

Good luck with it, LMK if you see any power increase.

 

[Idok]

I think you would like AV Gas, no Ethenol crap! Like you said its the same every where you buy it. (I make money when planes fall out of the sky, I also get what gas is left!)LOL I work at the airport so its no problem to get 100LL, just the airport manger likes to charge us $1.00 more than other local airports. I buy 3-400 gallons a month from the local airport. I'm thinking about filling a 55 gallon drum to save a few bucks.

Good luck with it, LMK if you see any power increase.

where woudl you get the drum? :scratchchin:


at 2.69 thats almost cheaper than pump premium!

 

[masterblaster]

Aircraft... A buddy of ours had a connec at the local airport here yrs back,he was getting the 55 gallon drums of av100 for free,something like the mandatory pump off of the top or bottom of the fuel tankers for condensation. They had to dispose of it anyway so he came and picked it up already in the drums.
He said it always ran perfect in his race skis,but the contact is gone now.do they have to do this pump off for condensation by law in every state. Might be worth a trip back up there to see if they will still give it away

 

[Aircraftsalz]

Aircraft... A buddy of ours had a connec at the local airport here yrs back,he was getting the 55 gallon drums of av100 for free,something like the mandatory pump off of the top or bottom of the fuel tankers for condensation. They had to dispose of it anyway so he came and picked it up already in the drums.
He said it always ran perfect in his race skis,but the contact is gone now.do they have to do this pump off for condensation by law in every state. Might be worth a trip back up there to see if they will still give it away

Your correct, all airports have to pump there tanks & trucks every day. Its worth the trip! My airport manger has it pumped & won't let anyone near it the 55 gallon drums. He's got camera's on the fuel farm & self serve pumps now days.

 

[masterblaster]

well what is he doing with it? disposal?

 

[Waternut]

Most likely paying to have it disposed of... When I worked for an airline, a couple guys said that they would run their diesel cars/trucks off the Jet A fuel that was drained prior heavy maintenance. Too many regulations now and they aren't allowed to do that anymore. Now it just sits in a big tank until it's picked up.

 

[masterblaster]

Jet A is very clean diesel.hopefully regulations havnt made it as hard to get 100av drain off,im going to check on it this week.

 

[Aircraftsalz]

well what is he doing with it? disposal?

He has it pumped out once a month. We use to use the Jet A in our fork lifts & yard trucks. With Jet A you should add some oil to use in auto's etc. Its hard on the injection pump, etc.

 

[Aircraftsalz]

where woudl you get the drum? :scratchchin:


at 2.69 thats almost cheaper than pump premium!

I got a oil drum thats almost empty, very clean & will make a great fuel drum. I also have some plastic drums I use when taking airplanes airpart. I got ya covered!

 

[OBXJeepGuy]

I know FAA regs say you can't put fuel back in a plane you take it out of. Something about contamination. I did have a contact at a place called Flight International that does plane maintainance. I always left there with a few 5 gallon jusgs of the stuff. I wish that were true now! I have long since lost that contact, and everyone I know pours the gas back in their plane if they take it out...

 

[OBXJeepGuy]

Just to give you an idea how AVGAS prices can differ:


100LL Avgas prices within 75 miles of KMQI

Airport / FBO100LL[SIZE=-2]$2.85—$4.45[/SIZE]
[SIZE=-2]average $3.49[/SIZE]


[SIZE=+2]KMQI[/SIZE] Dare County Regional Airport Manteo, NC[SIZE=-1]Dare County Regional Airport[/SIZE] SS $3.30 FS $3.80 [SIZE=-2]27-Feb[/SIZE]

[SIZE=-1]update[SIZE=+2]KECG[/SIZE] 31 NW[/SIZE] Elizabeth City Coast Guard Air Station/Regional Airport Elizabeth City, NC Elizabeth City/Pasquotank County Regional Airport

SS $3.47 FS $3.77 GUARANTEED

[SIZE=+2]KONX[/SIZE]
[SIZE=-1]33 NNW[/SIZE] Currituck County Airport Currituck, NC[SIZE=-1]Currituck County[/SIZE] SS $2.85 [SIZE=-2]19-Mar[/SIZE]
[SIZE=-1]update[/SIZE][SIZE=+2]KEDE[/SIZE]
[SIZE=-1]43 W[/SIZE] Northeastern Regional Airport Edenton, NC[SIZE=-1]Edenton Aviation Services[/SIZE] AS $3.99 [SIZE=-2]30-Jan[/SIZE]
[SIZE=-1]update[/SIZE][SIZE=+2]KPMZ[/SIZE]
[SIZE=-1]52 W[/SIZE] Plymouth Municipal Airport Plymouth, NC[SIZE=-1]Plymouth Municipal Airport[/SIZE] AS $3.49 [SIZE=-2]02-Mar[/SIZE]
[SIZE=-1]update[/SIZE][SIZE=+2]KCPK[/SIZE]
[SIZE=-1]54 NW[/SIZE] Chesapeake Regional Airport Norfolk, VAHorizon Aviation Services

SS $3.35 FS $3.85 GUARANTEED

[SIZE=+2]KPVG[/SIZE]
[SIZE=-1]63 NW[/SIZE] Hampton Roads Executive Airport Norfolk, VAVirginia Aviation AssociatesShell SS $2.94 FS $3.44 GUARANTEED [SIZE=+2]KSFQ[/SIZE]
[SIZE=-1]63 NW[/SIZE] Suffolk Executive Airport Suffolk, VASuffolk Executive AirportShell SS $2.98 FS $3.48 GUARANTEED

[SIZE=+2]KORF[/SIZE]
[SIZE=-1]63 NNW[/SIZE] Norfolk International Airport Norfolk, VA[SIZE=-1]Landmark Aviation[/SIZE] FS $4.45 [SIZE=-2]02-Apr[/SIZE]
[SIZE=-1]update[/SIZE][SIZE=+2]KFKN[/SIZE]
[SIZE=-1]75 NW[/SIZE] Franklin Municipal-John Beverly Rose Airport Franklin, VAFranklin Municipal AirportShell FS $3.23 GUARANTEED