Sunoco 110 Octane Racing Gas ?

[Cujet]

100LL avgas suffers from the same problem as Sunoco Standard 110. In an NA automotive engine, at ground level, it can be sluggish in terms of throttle response. This is due to the initial boiling point and lower end of the distillation curve being rather high. Avgas has to have a higher boiling point to ensure the fuel doesn't evaporate at high altitude and cause vapor lock that stalls the engine mid-flight. They're not concerned about how the fuel performs at ground level. It's plenty adequate enough for planes that are rich at takeoff anyway. They care that the fuel is stable at 15,000 ft where air pressure is only about half that of sea level. It'll still run fine in a car engine at ground level, just throttle response will suffer some.

The distillation curve of 100LL is generally different than today's auto fuel. However, that does not mean it evaporates slowly or will result in sluggish throttle response. 100LL works incredibly well in certain engines.

Pilots have been throwing 100LL on the ground for ages. Before the ramp attendant can get out to the plane to yell at the pilot, it's evaporated and gone. leaving no visible evidence.

100LL will vaporize at sub zero temps, and engines will both start and run properly under more conditions than typical auto fuels. This is generally of no advantage for the typical race fuel user.


Before anyone purchases 'race' fuel it is best to have a good understanding of the fuel and its characteristics. There are no true 101+ octane 'non-oxygenated' unleaded fuels. In real world terms, 96 octane R+M/2 is about it for a standard unleaded fuel.

Many of Sunoco's high octane unleaded fuels are highly oxygenated. Generally with lots of ethanol.

 

[RDY4WAR]

The distillation curve of 100LL is generally different than today's auto fuel. However, that does not mean it evaporates slowly or will result in sluggish throttle response. 100LL works incredibly well in certain engines.

Pilots have been throwing 100LL on the ground for ages. Before the ramp attendant can get out to the plane to yell at the pilot, it's evaporated and gone. leaving no visible evidence.

100LL will vaporize at sub zero temps, and engines will both start and run properly under more conditions than typical auto fuels. This is generally of no advantage for the typical race fuel user.


Before anyone purchases 'race' fuel it is best to have a good understanding of the fuel and its characteristics. There are no true 101+ octane 'non-oxygenated' unleaded fuels. In real world terms, 96 octane R+M/2 is about it for a standard unleaded fuel.

Many of Sunoco's high octane unleaded fuels are highly oxygenated. Generally with lots of ethanol.

I will take back some of what I said as it was too blanketed. My experience with this is in naturally aspirated drag cars. Generally, the fuel's 20% distillation should be lower than coolant temp for crisp throttle response. This has been observed with sensors on a dyno measuring power at tip-in. It's not a substantial difference in the seat. Avgas's 20% point is ~195°F. By comparison, pump gas is ~140°F, VP C25 (the gold standard for NA drag engines) is ~135°F and VP C11 is ~130°F. When you have drag engines with coolant temps <150°F, this can make a difference. You'll hear guys saying the engine lost ET in the 1/4-mile with C16 or another high curve fuel and blame it on the octane being too high. When you dig into it though, the MPH didn't change. The ET between 330-660 and 660-1320 didn't change. The engine was still making good power, just wasn't flashing the converter as hard because the engine wasn't responding as well on the hit. They'd lose .05 in the 60ft time which cost them a tenth or so at the 1/4-mile. Not a substantial difference for most, but that's a lot for something like an NHRA stock eliminator. They'd blame the octane, switch to 100LL, and have the same problem. They put in C11 and the response comes back.

Now if engine temps are cold enough, it will start affecting power as you'll push more and more unburnt fuel out of the exhaust. Sunoco claiming SR18 is good for NA drag race engines is nothing more than marketing. I'm so glad that VP is coming back to NHRA in 2025 with C25 becoming the main fuel for Pro Stock again.

 

[Astro14]

At VIR they have one of those old blending ones for show, it's super cool! The 110 stuff has lead in it also BTW, I've run the 100 before and logged to see if I was gaining anything, I wasn't for the ~$10/gal that I can't get with a few gallons of corn (E85 for 1/4 the price). My UOAs after tracking and using the race fuel have had small hits of Pb in them. I just bring 2 5 gal race cans of E85 which lasts me a weekend blending it down to E20-25 or so for knock resistance.

View attachment 254461

I was under the impression that the 260 GT was in fact unleaded gasoline. 100 octane, yes, but unleaded.

https://www.sunocoracefuels.com/fuels/fuel/260-gt

 

[TiGeo]

I was under the impression that the 260 GT was in fact unleaded gasoline. 100 octane, yes, but unleaded.

https://www.sunocoracefuels.com/fuels/fuel/260-gt

Why do I always see Pb in my UOAs after using it? I've used it twice and both UOAs showed Pb...only time I've seen Pb...always assumed it had to do with the gas. I understand it says unleaded which would make sense.

 

[Astro14]

Why do I always see Pb in my UOAs after using it? I've used it twice and both UOAs showed Pb...only time I've seen Pb...always assumed it had to do with the gas. I understand it says unleaded which would make sense.

I was wondering the same thing, which is why I brought it up.

I wonder if there’s some mixing in the pump perhaps?

Maybe they’re filling the pump with the wrong product?

 

[TiGeo]

I was wondering the same thing, which is why I brought it up.

I wonder if there’s some mixing in the pump perhaps?

Maybe they’re filling the pump with the wrong product?

Probably cross contam. It's happened however at 2 different tracks so each time I saw a touch of Pb it 1) after I used this product and 2) at a different track.

 

[SARG52]

You need to have a lot of trust in a corporation's honesty.

I recall many decades ago I worked at a Sunoco station and the owner had an extra long hose on one of the pumps. He used it after dark when closed to fill the "260" tank from lower grade tanks.
Today I often wonder if all the "grades" come out of the same pot.

 

[TiGeo]

You need to have a lot of trust in a corporation's honesty.

I recall many decades ago I worked at a Sunoco station and the owner had an extra long hose on one of the pumps. He used it after dark when closed to fill the "260" tank from lower grade tanks.
Today I often wonder if all the "grades" come out of the same pot.

At a race track that is highly unlikely as it will present its very quickly

 

[thastinger]

Probably cross contam. It's happened however at 2 different tracks so each time I saw a touch of Pb it 1) after I used this product and 2) at a different track.

It is common for 260 and 260gt to show lead in the 40-50ppm range on UOAs, you're not the only one who has had this happen and when they switched fuels the lead went away on the next sample. Both fuels contain MMT so you'll probably see some orange in the tailpipe and spark plugs.

 

[CarlB]

I was at one of the local gas stations here in town getting some propane yesterday, and they had Sunoco 110 Octane "Racing Gas" for $10.00 a gallon. I talked to the attendant about it, but he couldn't tell me much. Except they don't sell much of it. He said the dirt bike guys buy it, and the race boats in the Summer.

He didn't know anything else about it. Does all this stuff have to offer is the octane boost? That seems pretty steep for costing almost 3 times as much. I wonder if there is anything to be had running 2 stroke engines on it?

I remember years ago, (early 70's), Sunoco had the "Custom Blending Pump" that had all kinds of different grades. Up to Sunoco 260, which was supposed to be over 100 octane. But that was back in the days of leaded gas.

I wonder if this stuff is any different, (or better), than 100 LL Aviation gas? Other than it's most likely unleaded, with a tad more octane. I'm looking for an excuse to buy some, but I honestly can't think of a reason. Maybe air cooled generators running in very high temperatures under full load?

It's a leaded fuel, so not sure if your generators want that. I use it on track for certain vehicles for increased knock protection.

As far as "different or better" than AV fuel, it depends on application. This stuff is meant for 4-stroke terrestrial engines in terms of the mixture to achieve that octane. (flame speed, BTU, etc can all vary as you blend). It's better for cars than AV fuel, worse for airplanes than AV fuel, but also worse than 100 non-leaded for most vehicle applications.

tldr: If you aren't sure if you need it, you don't.

 

[Dave P.]

You need to have a lot of trust in a corporation's honesty.

I recall many decades ago I worked at a Sunoco station and the owner had an extra long hose on one of the pumps. He used it after dark when closed to fill the "260" tank from lower grade tanks.
Today I often wonder if all the "grades" come out of the same pot.

And the truckers themselves. I was told a story a few years back by a trucker I know who used to deliver gasoline. It was a common occurrence for station owners to have the drivers drop "regular" into the "Super" tanks and pay the driver a few bucks to do so. When the trucker who told me this story expressed his desire to not participate, they made him an offer he couldn't refuse and he ended up having to quit for his own personal safety. They were not going to allow one guy to screw up their side hustle. With all the electronics probably now involved in the record-keeping, this practice may not be possible anymore but I certainly don't know.

 

[Cujet]

And the truckers themselves. I was told a story a few years back by a trucker I know who used to deliver gasoline. It was a common occurrence for station owners to have the drivers drop "regular" into the "Super" tanks and pay the driver a few bucks to do so. When the trucker who told me this story expressed his desire to not participate, they made him an offer he couldn't refuse and he ended up having to quit for his own personal safety. They were not going to allow one guy to screw up their side hustle. With all the electronics probably now involved in the record-keeping, this practice may not be possible anymore but I certainly don't know.

I experienced this when driving around a particular town. My Jaguar's 27mpg would suddenly drop to 16mpg (or less) when I purchased fuel there. I could read knock events on the scan tool and they were through the roof. And the engine would soon refuse to go over 3000 RPM.

I tried different stations, even ones that were a few towns away. The only station that I never had trouble with was Shell. My research indicated that it was not the station who was responsible, but organized crime at distribution.

No joke, I had one tank of "93 octane" that went 60 miles and I was down to half a tank. I don't know how they pulled that off, but it was amazing to watch the fuel gauge drop in real time! Normally, 400 miles per tank and about 220 miles when indicating half a tank.

 

[TiGeo]

I experienced this when driving around a particular town. My Jaguar's 27mpg would suddenly drop to 16mpg (or less) when I purchased fuel there. I could read knock events on the scan tool and they were through the roof. And the engine would soon refuse to go over 3000 RPM.

I tried different stations, even ones that were a few towns away. The only station that I never had trouble with was Shell. My research indicated that it was not the station who was responsible, but organized crime at distribution.

No joke, I had one tank of "93 octane" that went 60 miles and I was down to half a tank. I don't know how they pulled that off, but it was amazing to watch the fuel gauge drop in real time! Normally, 400 miles per tank and about 220 miles when indicating half a tank.

How is that even possible in any concievable fuel quality scenario? Even if I ran 87 in my aftermarket tuned VW (93), I could drive it normally without an additinal knock retard being recorded or any drop in mpgs that would be notable. At what you described, your car shouldn't have been able to drive.

 

[RDY4WAR]

When I was a teenager in the early 2000s, my dad and I built a pretty hot 347ci SBF for his '86 Mustang. It was high compression, needed 93, and there was one gas station that it really didn't like. Went to it the first time, got premium, and we'd get misfire/detonation at WOT. We topped off with some C16 we had on hand and it went away. We thought maybe it was just a bad batch or maybe that gas was just old as they may not sell a lot of it. We didn't know. A few months later, we went by that station again, and had the same problem with detonation. We had to supplement a couple gallons of C16 again. Premium from any other gas station was just fine so we didn't go to that station anymore and never gave it much more thought. After reading some of these posts, I'm wondering now if that gas station was doing something shady.

 

[Bighorn2500]

Used to run the Sunoco 110 or the Torco 108 from another station mixed with Klotz R-50 at 32:1 in my Kawasaki KX250.

 

[Cujet]

How is that even possible in any concievable fuel quality scenario? Even if I ran 87 in my aftermarket tuned VW (93), I could drive it normally without an additinal knock retard being recorded or any drop in mpgs that would be notable. At what you described, your car shouldn't have been able to drive.

The 2003 Jag X-Type with 2.5L engine is extremely sensitive to octane. The programming is such that once the engine has a certain number of knock events, it not only pulls timing excessively, but limits RPM to 3000. Around town, low MPG and power is what's noticed. Once on the highway, within about 5 minutes on regular fuel, the RPM is limited.

People feed these cars regular gas, then have all sorts of problems. It is the octane that causes the 3000 RPM limit, other 'limp home' modes have different RPM limits. As I mentioned, that particular car is a great 'octane tester' and really highlights when a gas station is selling regular through the 93 pump.

https://www.jaguarforums.com/forum/x-type-x400-14/my-x-type-wont-go-past-3000rpm-70276/

 

[TiGeo]

The 2003 Jag X-Type with 2.5L engine is extremely sensitive to octane. The programming is such that once the engine has a certain number of knock events, it not only pulls timing excessively, but limits RPM to 3000. Around town, low MPG and power is what's noticed. Once on the highway, within about 5 minutes on regular fuel, the RPM is limited.

People feed these cars regular gas, then have all sorts of problems. It is the octane that causes the 3000 RPM limit, other 'limp home' modes have different RPM limits. As I mentioned, that particular car is a great 'octane tester' and really highlights when a gas station is selling regular through the 93 pump.

https://www.jaguarforums.com/forum/x-type-x400-14/my-x-type-wont-go-past-3000rpm-70276/

Wow, interesting...that is the same as my VW - what I'm getting at is being driven normally under normal load you shouldn't be knocking so excessively even on lower octane fuel for that to even be an issue...I get it for harder use. For my tuned car, even running winter blend 93 I can get enough KR events that it limps (no boost, no power but you can drive it) if you on it/pushing it/WOT in the higher RPMs.

Here's a limp mode event from excessive knock on track (can just key cycle to clear it without having to stop)...excessive knock, ECU richens mixture to point of misfires becoming too much and it goes kaput! Never mind the crappy driving...this was after just a few days on track on all seasons so a n00b still at that point...

 

[thastinger]

Wow, interesting...that is the same as my VW - what I'm getting at is being driven normally under normal load you shouldn't be knocking so excessively even on lower octane fuel for that to even be an issue...I get it for harder use. For my tuned car, even running winter blend 93 I can get enough KR events that it limps (no boost, no power but you can drive it) if you on it/pushing it/WOT in the higher RPMs.

Here's a limp mode event from excessive knock on track (can just key cycle to clear it without having to stop)...excessive knock, ECU richens mixture to point of misfires becoming too much and it goes kaput! Never mind the crappy driving...this was after just a few days on track on all seasons so a n00b still at that point...

The problem with the knock sensors is that the event has already happened.
Boostane works, I use the marine version because it i safe for cats and O2 sensors, pretty cheap to get 93 octane up to 99 octane.

 

[TiGeo]

The problem with the knock sensors is that the event has already happened.
Boostane works, I use the marine version because it i safe for cats and O2 sensors, pretty cheap to get 93 octane up to 99 octane.

I just run a few gallons of E85...much more effective and cheap.

 

[thastinger]

I just run a few gallons of E85...much more effective and cheap.

Gotcha, I'm not "flex" fuel capable. I can either run my E85 tune or my 93 tune and I have to drain the tank to switch.