Mixing Gas to get 93 Octane

[FarmallsForever]

Not sure if this is the correct spot for this topic; if not, Mods feel free to move it wherever is appropriate. The questions:

Is it okay to put leaded gas in a EFI vehicle? Talking to another engineer at work about this and he said that it causes problems with the injectors becoming fouled. Makes sense, but I am curious if this is true.

Also is mixing different octane rated gas okay for a EFI vehicle, as long as one does not mix leaded with unleaded? My understanding of the subject is that it would be okay, as long as it is unleaded. But would like to know for sure.

All this came about because there is no station that offers 93 octane gas here in Fargo or Moorhead. One of the local gas stations had 102 and 111. The 111 was off-road use only, guessing that is leaded but not sure (pump did not say). The 102 said was street legal, if that was leaded I don’t know, again the pump did not say. Here is a chart that was attached to the pump for mixing the 102/111 with 91 to get different grades of fuel. Don’t have a vehicle yet that justifies 93 octane but hope to have one someday. So basically this is to satisfy my curiosity. Sorry about the quality of the picture, only had my cell phone with me.

[POWERFREAK]

i didn't think leaded gas was legal anymore. I really doubt it's leaded...just higher octane.

[FarmallsForever]

Originally Posted by POWERFREAK

i didn't think leaded gas was legal anymore. I really doubt it's leaded...just higher octane.

Some of the gas stations up here sell it for off-road use (snowmobiles and the like) only. Use it quite a bit of it back at the farm in antique tractors that don’t have hardened valve/valve seats, and we haven’t got around to overhauling them in order to put them in. Most cases the amount that we use them doesn’t really justify a overhaul.

[flyer08]

I could have sworn i got 93 in fargo when i drove through the other week. Im in minot and dont make it down much so I could be wrong.

[Morepwr]

NO! The sensors on your engine will respond very bad to the leaded fuel! It also will hurt the catalytic convertor.

If you want to mix fuels to get an octane you want, then use an unleaded race gas.

[greenrail]

Try 104+ Octane Booster available at most Autoparts Stores and many Gas Stations.

It is an unleaded octane booster.

Also, BP Amoco Sells 93 Octane Fuel here.

I run Premium whether 91-92 or 93 Octane in my Camaro and haven't had any issues. But then I don't race the car either.

[Cmyskill]

If I can remember correctly octane boost really doesn't do that much. If it say it give you 2-3 point that is like going from 91 octane to 91.3 octane. Here in florida they sell 110 race fuel at a lot of stations and it is leaded. I only run 110 octain (leaded) in my talon and the only draw back is I have to replace my O2 about every 1000 miles or so. It is worth it because the car puts out 750hp @ 40Lb. boost. The lead is actually good for the valves and so forth as it adds a lubercant and/or cushion to parts. At least that is what I was told years ago... but I may be wrong....

[Banshee]

Originally Posted by FarmallsForever

Not sure if this is the correct spot for this topic; if not, Mods feel free to move it wherever is appropriate. The questions:

Is it okay to put leaded gas in a EFI vehicle? Talking to another engineer at work about this and he said that it causes problems with the injectors becoming fouled. Makes sense, but I am curious if this is true.

Also is mixing different octane rated gas okay for a EFI vehicle, as long as one does not mix leaded with unleaded? My understanding of the subject is that it would be okay, as long as it is unleaded. But would like to know for sure.

NO! No leaded fuel in any FI car....long list of reasons..1 catalytic converter, o2 sensors...injectors...

The only reason to put in anything higher than 93 UNLEADED into ANY car would be for higher compression in the 11's to 12's and upwards.

You do not need anything over 93 octane. You may see a negligible difference in performance with higher, but there is a curve..too much octane, you will foul, too little poor performance. If you tune, you may benefit from 96-98 octane, but why would you tune for 20-30 hp?

Anyhow, No leaded fuel, no mixing leaded and unleaded, and NO use of leaded in any FI car specifically marked "unleaded fuel only". There is a reason so stated.

[Hicompression]

Leaded gas will kill the cats.

[hot ss]

say no to lead, unless its in balloon like fords.

ethanol blended fuel with higher octane kinda kills perf too.
just use 91 and meth injection, if you need a tad more.
or i could mention adding pure tolulene, (not paint store thinner).
i have my flame suit on, lol.
this car's stock tune isnt really going to give you more power on higher octane anyway.
it will just give you a larger safety margin when heatsoaked.

[CamaroSpike23]

I'm going to move this to the engine section... then I'll be back in a min to comment more on the subject.

[Scrapppy666]

Originally Posted by Banshee

NO! No leaded fuel in any FI car....long list of reasons..1 catalytic converter, o2 sensors...injectors...

The only reason to put in anything higher than 93 UNLEADED into ANY car would be for higher compression in the 11's to 12's and upwards.

You do not need anything over 93 octane. You may see a negligible difference in performance with higher, but there is a curve..too much octane, you will foul, too little poor performance. If you tune, you may benefit from 96-98 octane, but why would you tune for 20-30 hp?

Anyhow, No leaded fuel, no mixing leaded and unleaded, and NO use of leaded in any FI car specifically marked "unleaded fuel only". There is a reason so stated.

I was told by a guy a few years ago that an engine w/ aluminum heads could handle 11:1 - 12:1 compression on 93 without detonating.... iron heads were maxed at 11:1 and would likely get some detonation at that level. (of course all of this was stated about non ecm vehicles that wouldn't compensate for knock and such)

There are countless threads across the internet that discuss octane booster and what substitutes people use (xylene , toluene etc.) which are the base ingredients in most booster. I'm not in any way recommending that, just what I've read.

[CamaroSpike23]

Originally Posted by FarmallsForever

Not sure if this is the correct spot for this topic; if not, Mods feel free to move it wherever is appropriate. The questions:

Is it okay to put leaded gas in a EFI vehicle? Talking to another engineer at work about this and he said that it causes problems with the injectors becoming fouled. Makes sense, but I am curious if this is true.

it is not ok to put leaded gas in a vehicle designed for unleaded. unless you have modified the engine to run leaded gas, dont mess with leaded gas


Also is mixing different octane rated gas okay for a EFI vehicle, as long as one does not mix leaded with unleaded? My understanding of the subject is that it would be okay, as long as it is unleaded. But would like to know for sure.

as long as its unleaded, its ok. just be aware of the fact that mixing the two different octanes isnt going to guarantee you your desired result.
say you want 93 octane, and mix 16 gallons of 91 with 4 gallons of 102. you should get close, but it might not be uniform throughout. (fluid dynamics and such dont always allow the two fluids to mix completely and you end up with areas of concentrated fluid, not that it will be detrimental to performance, as you would result with 93.2 in most of it and like 93.1 in other parts)

back on point, you can mix the two if you want, just check with the gas station to ensure that it is unleaded gas first.

All this came about because there is no station that offers 93 octane gas here in Fargo or Moorhead. One of the local gas stations had 102 and 111. The 111 was off-road use only, guessing that is leaded but not sure (pump did not say). The 102 said was street legal, if that was leaded I don’t know, again the pump did not say. Here is a chart that was attached to the pump for mixing the 102/111 with 91 to get different grades of fuel. Don’t have a vehicle yet that justifies 93 octane but hope to have one someday. So basically this is to satisfy my curiosity. Sorry about the quality of the picture, only had my cell phone with me.

the 111 is probably leaded and labeled as off-road due to the effect it has on the emissions systems in the car.

Originally Posted by hot ss

say no to lead, unless its in balloon like fords.

ethanol blended fuel with higher octane kinda kills perf too.
just use 91 and meth injection, if you need a tad more.
or i could mention adding pure tolulene, (not paint store thinner).
i have my flame suit on, lol.
this car's stock tune isnt really going to give you more power on higher octane anyway.
it will just give you a larger safety margin when heatsoaked.

yes and no. from 91 to 93 octane? no, it wont give you a noticable increase if any. however, 91/93 compared to 89/87 in the SS, it will be very noticable. the V8 camaros are designed to run on premium fuel, be it 91 or 93. running 87-89 in the V8s is asking for trouble. the v6 on the other hand does not see much of a benefit of running 91-93 over 89, but does show a slight benefit from running 89 over 87.

just food for thought.

Originally Posted by Scrapppy666

I was told by a guy a few years ago that an engine w/ aluminum heads could handle 11:1 - 12:1 compression on 93 without detonating.... iron heads were maxed at 11:1 and would likely get some detonation at that level. (of course all of this was stated about non ecm vehicles that wouldn't compensate for knock and such)

There are countless threads across the internet that discuss octane booster and what substitutes people use (xylene , toluene etc.) which are the base ingredients in most booster. I'm not in any way recommending that, just what I've read.

LT1's and LT4's have been running 11+:1 cr for years on 91/93 without detonating. which they were also aluminum heads and reverse flow cooling to boot.

I have a link hidden here somewhere to a comparison of leading octane boost products. and how all but 1 of them didnt raise your octane worth a damn.

it was due to the RON and MON numbers that are added together then divided by two to get your octane number... well, the octane boosters... say it "adds" 2 points, only adds it to the MON number. so your end result is less than advertised. and for 5-10 bucks a bottle, half a point to two points (at most) is not worth it.

[WeeZee]

98% 87 octane 10% 91 octane & 10% ethanol (100 octane) will get u 93 octane my buddy works for Marathon