How to find good quality gas?

[AJG]

I visited the JB4 forum to get my log checked and found out my fuel was crappy. How does everyone find quality gas to use without rolling the dice? I was going to a Top Tier shell station and getting 93 octane.

 

[seh0872]

That usually will do it...Top Tier, 91 or higher. Not sure what would cause a problem. Was it an old station? Maybe the tanks need to. E replaced. I’m religious about going to my local Shell station to ensure quality fuel.

 

[DGambit]

I visited the JB4 forum to get my log checked and found out my fuel was crappy. How does everyone find quality gas to use without rolling the dice? I was going to a Top Tier shell station and getting 93 octane.

Honestly just google top tier or high quality gas and check if any of those stations are near you. Shell, BP, and Costco are a few that are pretty common in areas

 

[MerlintheMad]

How did you get "bad" gas from Shell? Could the tank have been spiked? (I don't usually raise boogey men like that, but if only you are experiencing "bad" gas, I'd be suspecting a contamination event.)

 

[DGambit]

How did you get "bad" gas from Shell? Could the tank have been spiked? (I don't usually raise boogey men like that, but if only you are experiencing "bad" gas, I'd be suspecting a contamination event.)

Who said they got bad gas from shell?

 

[Stiletto]

I try to avoid Shell. Never ran as smooth as BP, Sunoco or Exxon Mobil in my previous cars.

 

[eflyguy]

All gasoline in a region comes from from same depot. The only difference is the additives each brand add, which has no impact on short-term performance

 

[MerlintheMad]

Who said they got bad gas from shell?

@AJG "I visited the JB4 forum to get my log checked and found out my fuel was crappy." He started this thread.

 

[Revvdmedia]

If you're using that log as reference, I'm seeing 17-18 peak PSI. That's map 3 IIRC. You're also seeing ignition values starting over 10 and peaking over 15. I'd call that a good run.

Us Canadians heavily question our gas quality. For comparison, in 4th gear WOT under Map 2, I was typically getting 3-5 degrees ignition advance, not 10 to 15...that was on supposed 94 octane gas. Similar story with Shell 91 octane which is supposedly the best we have. I might have had a "slow" Stinger but my fastest runs on Map 2 produced a best of 13.19s 0-60 @ 2200FT and I never saw a 0-60 in the 4's, EVER, always in the 5s.

 

[Stiletto]

All gasoline in a region comes from from same depot. The only difference is the additives each brand add, which has no impact on short-term performance

Yes, all refined gasoline comes from the same PADs. But, not just the additives, the ethanol, can make a difference in a tuned car. I should've clarified that in my post.

 

[AJG]

If you're using that log as reference, I'm seeing 17-18 peak PSI. That's map 3 IIRC. You're also seeing ignition values starting over 10 and peaking over 15. I'd call that a good run.

Us Canadians heavily question our gas quality. For comparison, in 4th gear WOT under Map 2, I was typically getting 3-5 degrees ignition advance, not 10 to 15...that was on supposed 94 octane gas. Similar story with Shell 91 octane which is supposedly the best we have. I might have had a "slow" Stinger but my fastest runs on Map 2 produced a best of 13.19s 0-60 @ 2200FT and I never saw a 0-60 in the 4's, EVER, always in the 5s.

I was running map2, after watching some youtube tutorials on reading the logs I'm in agreement that the log seems fine. Not sure what prompted the comment from Terry.

 

[Dodger Blue]

I basically just avoid Arco or off-brand stations (except for a nice one near my work that has race fuel and a good restaurant). Chevron, Mobil, Shell, 76 all work fine. Honestly the car doesn't seem all that picky as long as it's 91 octane.

 

[zbc1969]

Following. I recently found out the gas in Utah is complete shit. It took 5 gallons of e100 on top of my 91 pump gas from Chevron to fuse my logs.

 

[MerlintheMad]

Following. I recently found out the gas in Utah is complete shit. It took 5 gallons of e100 on top of my 91 pump gas from Chevron to fuse my logs.

Are you saying that Costco gas in Utah is de facto crap gas compared to Costco in other States? What does "Top Tier" mean to you?

 

[Revvdmedia]

Are you saying that Costco gas in Utah is de facto crap gas compared to Costco in other States? What does "Top Tier" mean to you?

IIRC, Top Tier mainly stipulates the minimum detergent mix, not necessarily octane. I think it would be illegal to call something 91 octane if it was not a minimum of 91 octane. I think the pumps calling it "minimum 91 octane" though is where we see the discrepancy. Perhaps the "bad" gas is very close to 91 octane, whereas the better performing fuel might actually be 91.5, 92, etc...

 

[zbc1969]

IIRC, Top Tier mainly stipulates the minimum detergent mix, not necessarily octane. I think it would be illegal to call something 91 octane if it was not a minimum of 91 octane. I think the pumps calling it "minimum 91 octane" though is where we see the discrepancy. Perhaps the "bad" gas is very close to 91 octane, whereas the better performing fuel might actually be 91.5, 92, etc...

no the octane is for sure off from what the sticker says. I can only assume this is from additives to try and make the gas pollute less as California has a similar problem with their 91 and we both have pollution and air quality issues. The octane doesn’t always match what the pump says. E85 Is a good example, In Utah people with flex fuel kits that give real time read outs never get actual e85. Usually it’s closer to E65. Also the fact that putting in a few gallons of e100 fixed my problems shows that the problem was low octane.

 

[zbc1969]

Are you saying that Costco gas in Utah is de facto crap gas compared to Costco in other States? What does "Top Tier" mean to you?

Can’t speak for Costco gas specifically but for other brands like Harmons, Shell, and Chevron, yes.

 

[Revvdmedia]

no the octane is for sure off from what the sticker says. I can only assume this is from additives to try and make the gas pollute less as California has a similar problem with their 91 and we both have pollution and air quality issues. The octane doesn’t always match what the pump says. E85 Is a good example, In Utah people with flex fuel kits that give real time read outs never get actual e85. Usually it’s closer to E65. Also the fact that putting in a few gallons of e100 fixed my problems shows that the problem was low octane.

I'd be genuinely curious to see some lab results from gasoline octane tests done by an unbiased party. Up in Canada we have "94 Octane" that is sold by Chevron, Petro Canada and Husky. Many people who tune their cars find that Shell 91 runs stronger than any of those 3 which really puts the octane rating to question. I believe most of those 94 blends up here say "up to 10% ethanol" on the pump, but I've heard they use a lot of octane booster (whatever that is for pump gas at stations) to get the "94" rating.

 

[zbc1969]

I'd be genuinely curious to see some lab results from gasoline octane tests done by an unbiased party. Up in Canada we have "94 Octane" that is sold by Chevron, Petro Canada and Husky. Many people who tune their cars find that Shell 91 runs stronger than any of those 3 which really puts the octane rating to question. I believe most of those 94 blends up here say "up to 10% ethanol" on the pump, but I've heard they use a lot of octane booster (whatever that is for pump gas at stations) to get the "94" rating.

yeah I think there can be a substantial amount of variance in octane. Normal cars can adjust for that and do fine but it becomes a problem when you’re trying to add a bunch of boost on top of that. I would also be curious. I wonder if there’s a company that tests fuel like blacks tone does for oil

 

[mandasol]

Underground gas tanks all have contaminates from the vacuum system sucking in air while you're fueling and also a lot of water that can form from condensation. Gasoline floats over water so the water just sits at the bottom of the tanks along with the sediments. There are sensors in the tanks that measure the gas and water. If the water gets too high it has to be pumped out and hopefully some of that sediment gets sucked up too. If the fuel level gets too low in tank the system should shut off so none of that water goes into your tanks but there's always the possibility of exception.

Gas pumps have vapor recovery systems that sucks in air while you're pumping so any dust or contaminates in the air can get sucked up in to the tanks. So don't fill up at a gas station near construction sites or dusty areas. There are vapor venting and recovery systems at the tanks also.

Also, you don't want to fill up right after or when they are getting their gas delivered as that will shake up the contaminates in the tank.

Underground tanks are lined to prevent corrosion but it still happens so many underground tanks leak as they older. When you're buying commercial property that had a former gas station or dry cleaners you have to have a stage II environmental test and the older properties often have contamination on site. It's so prevalent that all fuel sales contribute to a superfund insurance to help pay for clean up of these older sites. That also means contaminates from underground can go into the tanks so avoid gas stations that look more than 20 years old.