Chev94 , Vpower91. figure it out allready

[BC-Boy]

So this is a independent test i have done and i am in no way saying that chevron is falsely labeling their 94 octane as 94 but this is my experience.

Since i bought the car i have used nothing but chevron 94, its been great when its a good batch, but this spring and last fall i have got bad tanks of gas, 4-5 on maybe 25tanks. this year tho i have Ecutek software running a full bolton 93 map.
At the beginning of the year i had alot of trouble, my tuner said the gas im using was no better than cali 91 based on logs, put down 176 hp with jdl header and 2.5 to the tips drop in etc.. thats low, that sucks, and i was still getting knock!
When i came back from work in april, the gas had changed slightly, it was now better i could tell, i changed tuners because the one i had was to busy by the looks of it, and put down 185hp much better, 0 knock, very smooth running car.
2 tanks later (this week) i fill up from the exact same place, same pump, everything the same. 2miles down the road i stomp on it.. crack pop pop wtf? car pulled like crap and poping sound out the exhaust, so i grab my laptop and start logging , the IAM was at .33 . for those who dont know IAM is a function that the ecu uses to advance timing based on a healthy knock free motor in operation. so i reflash to get the IAM back up, immediately i try again slowly get on the throttle, at about 40% in 3ed i see it drop to .77 then gun it wot drops to .5 .. wow, the ignition was getting pulled in a very aggresive way, even cruising down the highway on light throttle and slight load if a small hill were to come up it would knock going up the hill.
So i burn tru this tank , speak to a bunch of local tuners and what not to get advise, some run vpower some run chevron 94, so i call every shell and chevron in town, ask how much 94 and vpower they sell, no chevron had a decent answer but one shell station told me they never go more that 4days between fill ups of 91 vpower. I made the switch
Instantly after a few miles i was logging and tried again slowly got on the throttle and it held up , a bit more ... good .. a bit more ... slight knock IAM at .9 .. WOT iam at .88 . but the engine ran very smooth and the ignition wasnt getting pulled so much, only tip in knock during a pull it would not retard timing. this gas ran MUCH better . its 91, chev was 94. based on the logs the 91 destroyed the 94, thus meaning the "94" was of much lesser quality than the 91. 90 ?89 ? thats 4-5-6 octane numbers LESS than it supposed. Logs dont lie. neither does a healthy running engine.
Conclusion is seems in my town and many other towns around here the chev 94 is hit or miss, some good batchs at the pump some bad, the vpower is allways steady,its not 94 but allways a solid 91.

[topazsparrow]

I wonder if there are any labs in town or Vancouver that can do a fuel analysis. A mechanic I used to know in Vancouver had always told me that Chevron was constantly better fuel based on his own tests (burning it in a petri dish or letting it evaporate and checking the residue). The gas varies from town to town though.

I would not be surprised to find out the gas is crappy and old, but if you're able to prove the octane level is falsely advertised, it could be huge.

[BC-Boy]

Originally Posted by topazsparrow

I wonder if there are any labs in town or Vancouver that can do a fuel analysis. A mechanic I used to know in Vancouver had always told me that Chevron was constantly better fuel based on his own tests (burning it in a petri dish or letting it evaporate and checking the residue). The gas varies from town to town though.

I would not be surprised to find out the gas is crappy and old, but if you're able to prove the octane level is falsely advertised, it could be huge.

well i dont want to stir a storm with this, just tell people of my experience so they can use that to help them with their choice, like i say i have got good tanks where i can run full advance in timing etc .... but allways 2-3 bad one to ruin it all, and when their bad they are like really bad, sub 91oct bad. which is terrible. dude, theres a car cuise , from k town to sicamous supposed to be going on this coming weekend. hit it up.

[Raven604]

What town are you in...add small town? Maybe I'll try our some 91 as well

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[topazsparrow]

Yea, we're both from the interior.

[FreshFRS]

i totally had this same debate with my boosted s2k, reiterating my post from the cricket thread, you have to find a station that has a lot of traffic using the pumps, fuel degrades when sitting, i definitely have had some bad tanks of Chev 94, but i've also had tanks that are far better than v-power 91, it just depends on how much fuel is moving through the station, the less sitting the better.

@Raven604, checkout some of the other car forums for the area GTR life, porcshe, BMW etc and see where those guys are fueling up, it helped me a lot when i first moved down south with my S2k.

We should just designate a certain station, in each major area of van, and then have as many people as possible use that one. everybody wins fresh gas = smoother running. impossible task but an idea nonetheless.

[Raven604]

That is a fantastic idea. I always try to fill up at high traffic stations like the one on the Mary Hill bypass in poco.

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[Raven604]

Also. Do this survey http://www.gtrlife.com/forums/topic/.../#entry1397282

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[topazsparrow]

Originally Posted by Raven604

That is a fantastic idea. I always try to fill up at high traffic stations like the one on the Mary Hill bypass in poco.

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The problem in the interior is that high traffic stations doesn't mean people are pumping premium gas.

We should probably have this thread moved to a regional board by now though. I'm not so sure the rest of the USA finds our conversation here particularly interesting.

[Apoc]

Originally Posted by BC-Boy

So this is a independent test i have done and i am in no way saying that chevron is falsely labeling their 94 octane as 94 but this is my experience.

Since i bought the car i have used nothing but chevron 94, its been great when its a good batch, but this spring and last fall i have got bad tanks of gas, 4-5 on maybe 25tanks. this year tho i have Ecutek software running a full bolton 93 map.
At the beginning of the year i had alot of trouble, my tuner said the gas im using was no better than cali 91 based on logs, put down 176 hp with jdl header and 2.5 to the tips drop in etc.. thats low, that sucks, and i was still getting knock!
When i came back from work in april, the gas had changed slightly, it was now better i could tell, i changed tuners because the one i had was to busy by the looks of it, and put down 185hp much better, 0 knock, very smooth running car.
2 tanks later (this week) i fill up from the exact same place, same pump, everything the same. 2miles down the road i stomp on it.. crack pop pop wtf? car pulled like crap and poping sound out the exhaust, so i grab my laptop and start logging , the IAM was at .33 . for those who dont know IAM is a function that Ecutek uses to advance timing based on a healthy knock free motor in operation. so i reflash to get the IAM back up, immediately i try again slowly get on the throttle, at about 40% in 3ed i see it drop to .77 then gun it wot drops to .5 .. wow, the ignition was getting pulled in a very aggresive way, even cruising down the highway on light throttle and slight load if a small hill were to come up it would knock going up the hill.
So i burn tru this tank , speak to a bunch of local tuners and what not to get advise, some run vpower some run chevron 94, so i call every shell and chevron in town, ask how much 94 and vpower they sell, no chevron had a decent answer but one shell station told me they never go more that 4days between fill ups of 91 vpower. I made the switch
Instantly after a few miles i was logging and tried again slowly got on the throttle and it held up , a bit more ... good .. a bit more ... slight knock IAM at .9 .. WOT iam at .88 . but the engine ran very smooth and the ignition wasnt getting pulled so much, only tip in knock during a pull it would not retard timing. this gas ran MUCH better . its 91, chev was 94. based on the logs the 91 destroyed the 94, thus meaning the "94" was of much lesser quality than the 91. 90 ?89 ? thats 4-5-6 octane numbers LESS than it supposed. Logs dont lie. neither does a healthy running engine.
Conclusion is seems in my town and many other towns around here the chev 94 is hit or miss, some good batchs some bad, the vpower is allways stady, not 94 but allways a solid 91.
I have also heard i dont know if its true its a muscle car shop here in the valley that told me this , chev 94 has up to 15% methanol, law does not request a company to label a methanol content here in canada, methanol as of ethanol do absorb water, methanol evaporates at a high rate, its made from natural gas and is cheap to produce. very corrosive metal parts.

I dont know if its true, but would make sense, im trying to find out for sure by contacting chev , but its hard to get a strait awnser. one thing if for sure , i solved the ongoing mystery of was that tank of gas really bad ? or is it just me?This pissed me off alot trying to dial in the car , thus the reason for such a long thread.

This doesn't sound like a bad batch of gas. It sounds like the station you are filling up at with chev 94 has a problem with water contamination or some other impurities. All top tier gasolines are regulated to death and I'm pretty sure it has to leave the refinery with proper octane rating and it would be an incorrect assumption that all the fuel is a lower octane than advertised. It's not some random rating that varies from batch to batch. The problem is as soon as leaves the refinery there are several ways water can get into to the gas just within the supply and it becomes a bigger problem when it gets delivered to a station and sits underground for weeks. Water in your fuel will pull timing like crazy and run like poop nearly the same as if you filled up with 87 oct. The key difference is low octane by itself shouldn't cause misfires. Also IAM is used across all subaru ECUs not just Ecutek roms. Anyways your timing will be pulled back in the same method because knock is being detected from the water messing up the fuel purity. Ideally if you could find a station that has consistently clean 94 oct your tune could apply more timing advance than you can do with VPower. Also if you do get a bad tank of gas, it's a good idea to have some fuel dryer or water remover handy.

[BC-Boy]

Originally Posted by Apoc

This doesn't sound like a bad batch of gas. It sounds like the station you are filling up at with chev 94 has a problem with water contamination or some other impurities. All top tier gasolines are regulated to death and I'm pretty sure it has to leave the refinery with proper octane rating and it would be an incorrect assumption that all the fuel is a lower octane than advertised. It's not some random rating that varies from batch to batch. The problem is as soon as leaves the refinery there are several ways water can get to the gas just within the supply and it becomes a bigger problem when it get to the station and sits underground for weeks. Water in your fuel will pull timing like crazy and run like poop nearly the same as if you fill up with 87 oct. The key difference is low octane by itself shouldn't cause misfires. Also IAM is the standard across all subaru ECUs not just Ecutek roms. Anyways your timing will be pulled back in the same method because knock is being detected from the water messing up the fuel purity. Ideally if you could find a station that has consistently clean 94 oct your tune could apply more timing advance than you can do with VPower.

thats exactly what i was saying, the quality of that tank which the pump was connected to was degraded for having sat too long or water, but this comes and goes, from great gas to very poor gas . 94 is a dying breed in bc chev is the only one left , and thats prob because its not used as much as other grades. im sure reglementation is very strict and im sure they are 100% honest in what they label it as, but i belive there should be some sort of quality control at the pump,where it matters, and for towns and cities that have a generaly low quality across all pumps , only have select stations offer 94. those who use it will make sure to use those stations im sure.

[topazsparrow]

Anyone know of any test kits that are available or labs that can test fuel?

A bit pricy, but something like this might work: [ame="http://www.amazon.com/OTC-7670-Gasoline-Quality-Testing/dp/B005LTINF4"]Amazon.com: OTC 7670 Gasoline Quality Testing Kit: Automotive[/ame]

[Triumphrider]

I strictly run Vpower in both the car and the bike. If I have to put any other gas in it, it is only enough to get me to a shell station. I used to run sunoco 94 in the bike and at trackdays the exhaust would have black soot all around the tip. Now I run the vpower and the exhaust just looks like someone blew white chalk dust in it. Burns incredibly cleaner. 13000 kms on my frs and no crickets or issues, but its only had vpower since day one. One other factor that may help is there are alot of BMW/ mercedes etc in my area that require premium gas. Hopefully that keeps me in fresh gas.

[BC-Boy]

Originally Posted by Triumphrider

I strictly run Vpower in both the car and the bike. If I have to put any other gas in it, it is only enough to get me to a shell station. I used to run sunoco 94 in the bike and at trackdays the exhaust would have black soot all around the tip. Now I run the vpower and the exhaust just looks like someone blew white chalk dust in it. Burns incredibly cleaner. 13000 kms on my frs and no crickets or issues, but its only had vpower since day one. One other factor that may help is there are alot of BMW/ mercedes etc in my area that require premium gas. Hopefully that keeps me in fresh gas.

yah i chose a shell thats on a hi traffic intersection , that is in a expensive area of town. apperently the tanks have been updated recently and the pumps as well, the overall station is pretty new its self seems like. A employee told me that they get all grades of gas topped up every 2-3 days and cant remember the last time they went over 4 days without a top up, in her opinion they sell alot of fuel based on other stations. so that sold me, just filled up there again this morn, logs are exactly the same no diff at all, im droping chev 94, allthough i have got great batchs i get too many bad ones and they are killer when there bad, im gonna mix the VP octanium half a bottle to 91 for 94oct ill run my 94 map for that and ill mix a entire bottle for 97 and run a hi octane map for that, run my 91 map anytime im just traveling or whatever . i also noticed the gas mileage seems better with vpower my roommate with his s2000 is doing the switch as well, and he noticed mileage difference and better idle .