is Costco brand gas bad for my M?

[Macky112]

was wondering if getting 91 octane from Costco bad for my M3?

yes i am cheap, lol

[JPH]

Costoc has the closest gas station to my house. I fill up there somewhat regularly...no problems. But, an informed answer would be good.

[skim]

Costco is what I fill up too.
I *heard* that costco actually buys gas from 76, but haven't been able to confirm.
But I do occasionally fill with Chevron time to time just to be sure M gets quality gas here and there at least.

[amk2912]

Originally Posted by Macky112

was wondering if getting 91 octane from Costco bad for my M3?

yes i am cheap, lol

I thought the S65 had to run on a minimum of 98RON? Any less would result in lower performance and higher consumption.

[Macky112]

Originally Posted by amk2912

I thought the S65 had to run on a minimum of 98RON? Any less would result in lower performance and higher consumption.

unfortunately, in CA we do not readily get access to octane rating over 91, so yes, from some dyno results on this forum, us running on 91 oct looses out on about 30+ hp

[sparkyg]

Is it Tier 1? If not don't buy it. There is plenty of shitty gas out there.

Cheap gas is generally shitty, there is a reason why BMW only recommends Tier 1 gas use.

I have actual experience with shitty Safeway gas in Canada that damaged my moms Corolla. All plugs were shot and so was the ignition.

[Cab5er]

Damn Taiwanese people. So cheap!

[smokinjoe64]

I've used Costco to fuel in both Cali and now MN over the last 10 yrs without issue in both my e39 540-6 speed and now the e92 M3. Here in MN the fuel contains 10% ethanol...still w/o a problem. Not sure if there is any real performance issue, but the buttometer says no.

[AlpWtE92]

The difference main between the different brands of gas is additives. There are strict federal and state standards for the gasoline that every refinery produces - so the gasoline produced by all the refineries, regardless of brand, are the same. This is why it is true that oil companies share gasoline - for example, Shell may sometimes sell gasoline from a Chevron refinery, etc. However, that is just gasoline before any additives are added.

The additives do make a difference. I'm not an expert on this part of it, but my understanding is that combustion will naturally result in the build-up of gunk in your engine, eventually affecting the performance of your engine. Additives help to keep your engine clean, and some additives are also supposed to enhance performance (though I do not if the performance claims are true). Generally top brands such as Chevron, Shell, Texaco spend a lot of time and money researching these additives and have proven their effectiveness over time. Cheaper brands and no name brands, like Costco, generally do not blend in additives that are as effective. In fact, I've heard from engineers that are in the industry that certain brands' additives will actually further contribute to the deterioration of engine parts.

I have relatives that get the cheapest gasoline that they can and I can definitely tell that after a year or two, their cars do not run as smooth as when they were new. I have been a loyal user of Chevron gasoline and the cars I have still run as smooth as new even after years of driving.

How much do you really save per tank by getting Costco gas? $2-3 per fill-up? Is that savings really worth the potential harm you'll do to your engine over time?

[AlpWtE92]

Originally Posted by smokinjoe64

I've used Costco to fuel in both Cali and now MN over the last 10 yrs without issue in both my e39 540-6 speed and now the e92 M3. Here in MN the fuel contains 10% ethanol...still w/o a problem. Not sure if there is any real performance issue, but the buttometer says no.

Interesting, do you consistently use their gas, or just sometimes? If you have used their gasoline consistently for the last 10 years and cannot tell a difference in performance in your cars, then your experience is definitely different from mine. If you mix in Costco gas with intermittent uses of top tier brands, you may not notice the difference.

[BMWM.D.]

In general, I do not recommend any of the bargain gas stations to people. I have always filled up my cars with premium fuel (91 in Ca) from 76 and it is worth the small amount of extra money, IMO.

BMW recommends using a Top Tier detergent gasoline with a minimum AKI of 91. Running fuel that is not Top Tier can result in excessive accumulation of deposits on fuel injectors, intake valves and inside the combustion chamber. This information is outlined in Service Information Bulletin SI B13 02 06.

It has always amazed me how many people put cheap fuel in their high end cars. It really is not that much more $$, and I feel the benefits outweigh the extra cost.

Here is some info I found on Top Tier gasoline in general:


In 2004 BMW, General Motors, Honda, and Toyota established a proprietary standard for a class of gasoline called Top Tier Detergent Gasoline with increased levels of detergents. Volkswagen/Audi joined the consortium in 2007.

Gas brands can participate and get Top Tier listing if they meet certain standards.


In 2004 the standard was adopted by just a few gasoline distributors, Chevron, QuikTrip, Kwik Trip, Conoco-Phillips, Shell, Entec Stations, and MFA Oil Company. Since then many gasoline distributors have met the proprietary standard and it can be found in numerous gas stations all over North America. Aloha Petroleum, KwikTrip, KwikStar, Somerset Refinery Inc., Tri-Par Oil Company, Shell Canada, Chevron Canada, Sunoco Canada and Petro Canada have since received Top Tier recognition.

[Kev]

Originally Posted by amk2912

I thought the S65 had to run on a minimum of 98RON? Any less would result in lower performance and higher consumption.

As you said, it's 98 RON. In the states, the octane rating or AKI is expressed as a mean of RON and MON (R+M)/2, so 91 AKI is about 95-96 RON. 93 AKI is the equivalent of 97-98 RON, but we do have ethanol added to our gas, which can possibly hurt engine in the long run.

[Robert]

They all come from the same refinery and the additives that so many rave about? There's a tiny amount of that in each gallon of gas and more is that most refinery are regulated by law to include engine cleaning solution in their gas.

[rsmamg]

something to think about:

what if the person before you pumping gas at the station used 87? then you pull up to the same pump and put in a few gallons (because i dont like to have a full tank most of the time ), wont you be pumping in the residual amount of 87 gasoline that the previous person pumped into their car that was left in the nozzle and hose?

IMO i dont think that should make a huge difference, just something to think about.

[amk2912]

Originally Posted by Kev

As you said, it's 98 RON. In the states, the octane rating or AKI is expressed as a mean of RON and MON (R+M)/2, so 91 AKI is about 95-96 RON. 93 AKI is the equivalent of 97-98 RON, but we do have ethanol added to our gas, which can possibly hurt engine in the long run.

Thanks for clarifying that! I have always run 98RON in my BMWs and for the sake of a few cents per litre, it's not worth putting cheap stuff in your car.

"Nothing good is cheap and nothing cheap is good!"

[Kev]

Originally Posted by amk2912

Thanks for clarifying that! I have always run 98RON in my BMWs and for the sake of a few cents per litre, it's not worth putting cheap stuff in your car.

"Nothing good is cheap and nothing cheap is good!"

No problem. I came from Hong Kong and used to seeing 98 and 102 RONs as well so it took me a while to figure out how the octane number works in the US.

I agree it's not worth that 10-15 cents a gallon to pump in the cheaper gas. My peace of mind is more expensive than that

[Salespunk]

Using Tier 1 gas is not "as" important with our motors as it is with Direct Injection motors. There have been alot problems reported on the RS4 motor when detergent gasoline is not used. Either way I still use Chevron and Shell most of the time. Not worth the risk for maybe $2 per tank.

[golemite]

I've always filled my turbo upgraded S4 and now my M3 with Costco gas... no problems at all. Have gotten bad batches at the local 76s but my S4 has always pulled fine numbers on 91 pump from Costco.

[Bluesummer]

Originally Posted by rsmamg

something to think about:

what if the person before you pumping gas at the station used 87? then you pull up to the same pump and put in a few gallons (because i dont like to have a full tank most of the time ), wont you be pumping in the residual amount of 87 gasoline that the previous person pumped into their car that was left in the nozzle and hose?

IMO i dont think that should make a huge difference, just something to think about.

I've always wonder the same thing as well, but i guess there's nothing I can do about it
________
real estate for sale Pattaya

[Nawaaz]

My family and I use Costco and Sam's gas very often. We've had absolutely no problems. When my M3 finally comes in, I'll probably use Shell's gas since I've heard it's the best. I'm just really picky when it comes to taking care of my high-performance machine.

[sparkyg]

I know everyone says all gases are the same, well they're not. It it is not just additives but other light ends that they add to the fuel to increase octane etc. I'd say 70-80% of a liter( gallon) is the same and the rest are all based on how that company chooses to make the fuel, what they have to mix it with and how cheap can they make it.

I have taken enough refining courses to say that there is a difference and that better gas is better gas.

There is also pleny of anecdotal evidence of off spec gas that has way too high alcohol content that can damage your car. Again a cheap Octane booster.

Will it make a difference to your car, maybe, maybe not, depends how long you use it and how the car operates.

I still think you drive a high performance car with a high compression engine you really should use the best gas you can get. Anything less and you are adding risk to your investment. Then again not sure how many people actually own their car these days.

Anyone know where Costco gets their gas from?

[Robo Squirrel]

i have only ever put shell v-power in my M3s