Octane Testing

AUTiger13 · 08-24-2014, 02:24 PM

I posted this in the general section, but thought I should post it in the regional forums too. This is specifically for the Texas guys, especially Houston.

About a year ago after moving down to Houston, I noticed my car (2011.75 e93 M3 DCT) began to develop a knock during downshifts when the car auto-blipped, and during acceleration. It would occur under load at a slow speed and during hard acceleration throughout the entire RPM range. I know exactly what knock/detonation sounds like so I began changing gas stations.

My car hates Shell for some reason. I would have to granny the car around so I wouldn't get knock. I have found two Chevron's nearby that I have started filling up at and the knock seems to be subdued, until recently. Im getting knock on the auto blips and now under medium and hard acceleration. I did a quick Google search and came across this news article, dated Feb 2014. Look at the map to see all of the gas stations the state ordered to close in the past few years! My car never had a problem with gas in Dallas...and I always make sure its 93 octane.

My question is in regards to the Complaint forms that are sent to the Department of Agriculture (at the bottom of the article, they post a link to the Dept. of Ag. to file a complaint against gas stations to have their gas checked). Has anyone ever had experience submitting a form to have a station checked? They ask for your contact information, so do they get back with you after they check the station to share their results?

In the interim, does anyone have a solution to combat the detonation? I just had my oil sent to Blackstone to see if any damage has occurred over the past year or so - should be getting it back this week.

bigjae1976 · 08-24-2014, 05:33 PM

You did the right thing by submitting the complaint. If you can find where that station gets their gas from then you might be able to deal directly with that terminal or refinery.

I35it · 08-25-2014, 10:33 PM

Very interested to see results because I was having the same issues with my Shell and Chevron station near my house. Brought it to the dealership and they are telling me that the onboard computer is saying it is lower then 93 octane gas. I was then informed to stop using those stations.

8k3 · 08-26-2014, 01:01 AM

Funny you posted this. Just today I was certain that various gas stations indeed do not pump out 93 as advertised. My car is supercharged and I can tell a difference in performance instantly. At first I thought I was nuts but certain gas stations were repeatable. I never knew who to report them to other than to their corporate office which would get no where probably. Thanks for the heads up. What a sham!

AUTiger13 · 08-26-2014, 06:58 PM

I would submit all gas stations you believe are mixing or selling sub-93 octane. This can do serious damage to our engines (especially if supercharged) and would be pissed if I had to shell (no pun intended) $20k for a new motor.

You would think that being in Houston would be a positive in regards to gas quality since were so close to the refineries. I guess you can't stop the stations from scamming us.

08-24-2014, 02:24 PM	#1
AUTiger13 Private 8 Rep 60 Posts Drives: 2018 X5 50i Join Date: Jul 2013 Location: Houston, TX iTrader: (0)	Octane Testing I posted this in the general section, but thought I should post it in the regional forums too. This is specifically for the Texas guys, especially Houston. About a year ago after moving down to Houston, I noticed my car (2011.75 e93 M3 DCT) began to develop a knock during downshifts when the car auto-blipped, and during acceleration. It would occur under load at a slow speed and during hard acceleration throughout the entire RPM range. I know exactly what knock/detonation sounds like so I began changing gas stations. My car hates Shell for some reason. I would have to granny the car around so I wouldn't get knock. I have found two Chevron's nearby that I have started filling up at and the knock seems to be subdued, until recently. Im getting knock on the auto blips and now under medium and hard acceleration. I did a quick Google search and came across this news article, dated Feb 2014. Look at the map to see all of the gas stations the state ordered to close in the past few years! My car never had a problem with gas in Dallas...and I always make sure its 93 octane. My question is in regards to the Complaint forms that are sent to the Department of Agriculture (at the bottom of the article, they post a link to the Dept. of Ag. to file a complaint against gas stations to have their gas checked). Has anyone ever had experience submitting a form to have a station checked? They ask for your contact information, so do they get back with you after they check the station to share their results? In the interim, does anyone have a solution to combat the detonation? I just had my oil sent to Blackstone to see if any damage has occurred over the past year or so - should be getting it back this week.
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08-24-2014, 05:33 PM	#2
bigjae1976 Major General 1579 Rep 8,077 Posts Drives: 11 E90 M3 Individual Join Date: Mar 2006 Location: Houston, TX iTrader: (22) Garage List 2004 BMW M3 [4.50] 2011 BMW E90 M3 [5.25] 2013 BMW 328i [5.00]	You did the right thing by submitting the complaint. If you can find where that station gets their gas from then you might be able to deal directly with that terminal or refinery. __________________ 2018 F30 320iX Melbourne Red 2011 E90 M3 Monte Carlo Blue 2004 E46 M3 Imola Red 2000 E36/7 Z3 Steel Blue
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08-25-2014, 10:33 PM	#3
I35it all day 48 Rep 1,181 Posts Drives: 2012 135i Join Date: Jul 2012 Location: Temple, TX iTrader: (10) Garage List 2004 Toyota Tacoma [0.00] 2009 VW GTI [0.00] 2012 135i [10.00]	Very interested to see results because I was having the same issues with my Shell and Chevron station near my house. Brought it to the dealership and they are telling me that the onboard computer is saying it is lower then 93 octane gas. I was then informed to stop using those stations.
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08-26-2014, 01:01 AM	#4
8k3 Banned 123 Rep 951 Posts Drives: Car Join Date: Feb 2013 Location: Boise, ID iTrader: (1)	Funny you posted this. Just today I was certain that various gas stations indeed do not pump out 93 as advertised. My car is supercharged and I can tell a difference in performance instantly. At first I thought I was nuts but certain gas stations were repeatable. I never knew who to report them to other than to their corporate office which would get no where probably. Thanks for the heads up. What a sham!
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08-26-2014, 06:58 PM	#5
AUTiger13 Private 8 Rep 60 Posts Drives: 2018 X5 50i Join Date: Jul 2013 Location: Houston, TX iTrader: (0)	I would submit all gas stations you believe are mixing or selling sub-93 octane. This can do serious damage to our engines (especially if supercharged) and would be pissed if I had to shell (no pun intended) $20k for a new motor. You would think that being in Houston would be a positive in regards to gas quality since were so close to the refineries. I guess you can't stop the stations from scamming us.
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