Costco Premium Gas Issue

caycep · 01-07-2021, 05:30 PM

Quote:

Originally Posted by morphomeman

The Top Tier designation is monitored by an outside body. So, unless you are ascribing Volkswagen-level corporate mendacity to Costco, I would not correlate the quality of their dried fruit brands with that of their gasoline.
For what it's worth, Costco, alone among big box stores, pays their employees a living wage.

Costo Auto also gets you nice discounts on new BMWs!

cowymo · 01-08-2021, 08:26 PM

I have to say Costco 91 gas isn't that "top tier". I have a classic car which operates on dual carburetors with zero electronic controls. I have always use Shell 91 due to zero ethanol and had zero problem with it. One day I decided to try out Costco 91 cos I have read that they are "top tier". After a tank of Costco 91, I never went back again. The car suffers from lost of power, backfires for the next 500km. I had to run the tank to half, mixed it back with Shell 91 and run another half a tank to wash out the Costco 91. After 2 tank of gas, the car was back to normal. Just my 2 cents.

aerobod · 01-09-2021, 01:57 AM

Quote:

Originally Posted by cowymo

I have to say Costco 91 gas isn't that "top tier". I have a classic car which operates on dual carburetors with zero electronic controls. I have always use Shell 91 due to zero ethanol and had zero problem with it. One day I decided to try out Costco 91 cos I have read that they are "top tier". After a tank of Costco 91, I never went back again. The car suffers from lost of power, backfires for the next 500km. I had to run the tank to half, mixed it back with Shell 91 and run another half a tank to wash out the Costco 91. After 2 tank of gas, the car was back to normal. Just my 2 cents.

In Canada Shell 91 is now the only gasoline that is readily available that is guaranteed to not contain ethanol. Any carbureted car will need to be re-jetted with larger jets to increase the fuel flow by 3% to run well on E10, the most common ethanol mix at the pumps.

morphomeman · 01-09-2021, 06:15 AM

Top Tier is simply a designation that the fuel has been tested by an organization that officially certifies it. That does not mean that the fuel is somehow 'the top tier'. The two have nothing to do with one another.

MarcoZandrini · 01-09-2021, 09:57 AM

Quote:

Originally Posted by morphomeman

Top Tier is simply a designation that the fuel has been tested by an organization that officially certifies it. That does not mean that the fuel is somehow 'the top tier'. The two have nothing to do with one another.

To add to what you've written, "top tier" refers to the fuel's ability to keep injectors and the back of intake valves (engines with injectors in the intake manifold) clean. It has nothing to do with the overall quality of the gas.

Sportstick · 01-09-2021, 10:19 AM

Quote:

Originally Posted by cowymo

I have to say Costco 91 gas isn't that "top tier". I have a classic car which operates on dual carburetors with zero electronic controls. I have always use Shell 91 due to zero ethanol and had zero problem with it. One day I decided to try out Costco 91 cos I have read that they are "top tier". After a tank of Costco 91, I never went back again. The car suffers from lost of power, backfires for the next 500km. I had to run the tank to half, mixed it back with Shell 91 and run another half a tank to wash out the Costco 91. After 2 tank of gas, the car was back to normal. Just my 2 cents.

As noted above, this reflects a misunderstanding of the term "top tier", a reference to the detergent package. Costco fuel exceeds this requirement. If you have an unusual car with specific fuel needs, Costco may not work for you in that car, but would work in your more typical vehicles.

https://www.costco.com/kirkland-signature-gasoline.html
https://www.costco.com/fuel-promise.html

cowymo · 01-09-2021, 01:29 PM

But the classic runs fine with other 91 or higher gas with 10% ethanol.

Sportstick · 01-09-2021, 02:10 PM

Quote:

Originally Posted by cowymo

But the classic runs fine with other 91 or higher gas with 10% ethanol.

Challenging to explain your experience. Any gas station can have an occasional issue of their own or due to the base fuel received from any of their local refinery suppliers. Your particular station may have an underground tank issue. Who knows? Perhaps the high level of detergent loosened some build-up? Could be a variety of factors. I think we can logically conclude that the number of users on this forum and the high volume of Costco gas customers attest to their ongoing quality.

cowymo · 01-10-2021, 08:57 AM

I guess I just had bad luck. Or maybe Canadian Costco gas and different from USA Costco.. who know? But i'm not going to find out.. LOL

jzeiler4 · 01-10-2021, 03:34 PM

I remember my Grandfather when he drove from Colorado to California for a visit in his 1956 Chevrolet (this was in '63). He filled up with Shell and the coil failed in the car a short time later. He never bought Shell gas again.

harma24 · 01-10-2021, 07:10 PM

Quote:

Originally Posted by jzeiler4

I remember my Grandfather when he drove from Colorado to California for a visit in his 1956 Chevrolet (this was in '63). He filled up with Shell and the coil failed in the car a short time later. He never bought Shell gas again.

Wonder what he would have done had he run over a nail after buying a new set of Goodyears...

morphomeman · 01-12-2021, 04:22 PM

The logical fallacy here has a wonderful Latin name: post hoc, ergo propter hoc, which translates as 'after this, therefore because of this'. It is unfortunately very widely observed.

Sportstick · 01-12-2021, 04:27 PM

Quote:

Originally Posted by morphomeman

The logical fallacy here has a wonderful Latin name: post hoc, ergo propter hoc, which translates as 'after this, therefore because of this'. It is unfortunately very widely observed.

Or...correlation is not causation!

I took, but failed, 7th grade Latin!

01-08-2021, 08:26 PM	#46
cowymo Private First Class 50 Rep 142 Posts Drives: 2021 BMW M440i XD Join Date: Nov 2020 Location: Ontario iTrader: (0) Garage List 1984 Mazda RX7 GSL [0.00] 1999 Subaru Sambar [0.00] 1970 VW Beetle [0.00] 2024 BMW Z4 [5.00] 2021 BMW M440i Coupe [0.00]	I have to say Costco 91 gas isn't that "top tier". I have a classic car which operates on dual carburetors with zero electronic controls. I have always use Shell 91 due to zero ethanol and had zero problem with it. One day I decided to try out Costco 91 cos I have read that they are "top tier". After a tank of Costco 91, I never went back again. The car suffers from lost of power, backfires for the next 500km. I had to run the tank to half, mixed it back with Shell 91 and run another half a tank to wash out the Costco 91. After 2 tank of gas, the car was back to normal. Just my 2 cents.
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01-09-2021, 06:15 AM	#48
morphomeman Major 593 Rep 1,219 Posts Drives: 2015 M235ix Join Date: May 2015 Location: United States iTrader: (1) Garage List 2016 BMW X3 [0.00] 2015 BMW M235ix [0.00]	Top Tier is simply a designation that the fuel has been tested by an organization that officially certifies it. That does not mean that the fuel is somehow 'the top tier'. The two have nothing to do with one another.
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01-09-2021, 01:29 PM	#51
cowymo Private First Class 50 Rep 142 Posts Drives: 2021 BMW M440i XD Join Date: Nov 2020 Location: Ontario iTrader: (0) Garage List 1984 Mazda RX7 GSL [0.00] 1999 Subaru Sambar [0.00] 1970 VW Beetle [0.00] 2024 BMW Z4 [5.00] 2021 BMW M440i Coupe [0.00]	But the classic runs fine with other 91 or higher gas with 10% ethanol.
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01-10-2021, 08:57 AM	#53
cowymo Private First Class 50 Rep 142 Posts Drives: 2021 BMW M440i XD Join Date: Nov 2020 Location: Ontario iTrader: (0) Garage List 1984 Mazda RX7 GSL [0.00] 1999 Subaru Sambar [0.00] 1970 VW Beetle [0.00] 2024 BMW Z4 [5.00] 2021 BMW M440i Coupe [0.00]	I guess I just had bad luck. Or maybe Canadian Costco gas and different from USA Costco.. who know? But i'm not going to find out.. LOL
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01-10-2021, 03:34 PM	#54
jzeiler4 Lieutenant 320 Rep 536 Posts Drives: 2021 M240i xDrive vert Join Date: Aug 2020 Location: Hazel Green, AL iTrader: (0)	I remember my Grandfather when he drove from Colorado to California for a visit in his 1956 Chevrolet (this was in '63). He filled up with Shell and the coil failed in the car a short time later. He never bought Shell gas again.
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01-12-2021, 04:22 PM	#56
morphomeman Major 593 Rep 1,219 Posts Drives: 2015 M235ix Join Date: May 2015 Location: United States iTrader: (1) Garage List 2016 BMW X3 [0.00] 2015 BMW M235ix [0.00]	The logical fallacy here has a wonderful Latin name: post hoc, ergo propter hoc, which translates as 'after this, therefore because of this'. It is unfortunately very widely observed.
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