Costco Gasoline

[dinodiesel]

I see now that Costco gasoline now states that it has top tier detergent additive. So typically I get 87 octane Shell, or 91 octane Costco but add a bottle of Techron every month. Maybe this makes this unnecessary? What think the list members?

 

[homeofstone]

All gasolines are pumped from the same storage tanks at a depot facility into tanker trucks of the various brands. Each brand's jobber adds their additives then. Some add nothing. So I think what Costco is saying is that they are buying from a brand that has additives.

 

[EXBMWGUY]

Techron is probably only advisable every 7500 miles if you use top tier fuel.

 

[QCTLG]

I recently just did a 600KM (372.82M) trip and got 6.9L/100KM (34.09MPG) and was traveling at 110KMH (68.35MPH)
Temp was 25C (77F) pretty calm winds.
This is by far the best I've ever gotten from my car.
I have a 2009 V8 and now have 125KM's on my car.

It amazes me that after all that mileage I fell like my car is in it's top zone.
Car just purrs along and is still very smooth after more than 4 years of ownership!

FWIW I still love this car very much!!

Why am I saying this here?

Because I have NEVER put anything in my gasoline tank.
no techron, no cleaners, nothing.
I am guilty of having tried some 91 octane gas and maybe once or twice 94 octane and felt absolutely NOTHING!
99% is 87 octane gas...period

Kind regards,

 

[Rey]

Gasoline always seems to prompt debate and comments, so here's mine

Gasoline degrades gradually as soon as it leaves the refinery. Costco pumps a lot of gas so there gas is comparatively "fresh". It is also cheaper. When traveling I buy gas at high-volumne truck stops. Gas is cheaper and fresher.

I'm on my 4th Genesis - 3 V8s and now a V6. Always found better gas mileage on highway travel using 87 octane. I have found this to be true with other high-compression autos (Jaguar, BMW, Cadillac CTS-V); but I think this is mostly true with highway, light throttle settings. At light throttle no detonation is detected. In town with heavier throttle acceleration detonation is more likely, which in turn causes ignition advance to retard, which reduces gas mileage. So, premium seems to make more sense to me with in-town driving.

I add a couple of bottle of Techron (bought at Costco, of course) with every oil change. Currently, Hyundai is recommending fuel injection cleaner periodically; and the house brand (expensive) is Techron with a private Hyundai label. Direct fuel injectors seem to require cleaner. My guess is that one can defer this maintenance, but eventually injectors will have to be cleaned.

Hyundai V8s seem to loosen up/fully break in after 10K miles. Gas mileage improves and so does power. Ring seating seems to set and then loosen, only to set again. Noticed that oil consumption rose a bit with short in-town travel, but settled down after a few hundred continous highway miles.

Piston ring blow-by seems to be a problem with direct injected V8s when the rings are not fully seated. Crankcase ventilation could be better as a fair amount of blowby oil mist is sent to the intake manifold. With manifold injectors this oil mist is mixed/diluted with gasoline before intro into the combustion chamber. With direct injection there is a tendency for oil mist to coat the back side of intake valves, which can become problematic.

 

[wchettel]

My brother recently told me that he buys most of his gasoline at COSTCO. He said that in addition to the significant discount at the pump, he gets an add'l 4% cash back by using his COSTCO/AMEX credit card.

I was curious if they sold TOP TIER gas at their warehouse locations. So, I went to their website and was going to send a query about top tier gas. When I clicked 'continue' on my email query, the following message popped up:

Top Tier Gasoline

All gasoline retailers in a given market sell the same grade and quality fuel, as the government has very precise standards for octane and other gasoline characteristics. The only difference between different brands of fuel is the detergent additive package. Since 1995, the federal government requires that all gasoline sold in the U.S. contain detergent additives. These additives must be EPA-approved, and the government specifies the amount based on what it takes to keep engines free of deposits. Because it's a performance-based requirement, over the years the fuel suppliers have figured out ways to use less of these expensive additives to achieve the government standards. All Costco gasoline contains detergent additives in the amount necessary to meet these requirements.

Recently, several automakers (BMW, GM, Toyota, and Honda) announced their new "Top Tier" standard for gasoline, as they believe the government additive requirement is too low. They invited gasoline manufacturers to certify their fuel to this higher standard, and several have done so. Other major oil companies, such as BP, declined as they believe the auto manufacturers are simply trying to reduce their warranty claims. To achieve this voluntary "Top Tier" designation, all the fuel sold in the U.S. must meet the higher standard. Costco cannot currently do this as we buy from a variety of refiners and distributors around the country and do not own our own truck terminals where the additives are blended with the fuel.

Nor is it certain how much additive is really necessary to keep an engine clear of deposits. The fuel detergent is only one component, as anything that causes incomplete combustion will lead to valve deposits and fuel injector clogging. It's easy for an auto mechanic to simply declare the problem is the gasoline. So the science is uncertain, and the industry response is certainly not unanimous. Regardless, we are actively researching the issue directly with the various additive manufacturers. We are hesitant to raise the cost of fuel to our members without first understanding if this is simply a way for some brands to charge more for their fuel. We do know that we sell a tremendous amount of fuel with very few complaints.

Costco only buys fuel from reputable suppliers, and we do a very good job of maintaining our tanks and pump filters to assure clean fuel is delivered to our members. If you remain concerned about fuel deposits, Costco sells a four-pack of Chevron's Proguard fuel injector cleaner in our warehouses for about $10, or $2.50 per bottle. It's much less expensive to use a bottle of this occasionally than to buy higher priced fuel every time you fill up. Any auto parts store has a shelf full of similar products.

Again, all Costco fuel contains detergent additives sufficient to meet the government standards. As with anything we sell, our fuel is 100% guaranteed.​

 

[Mark_888]

Costco - "They invited gasoline manufacturers to certify their fuel to this higher standard, and several have done so. Other major oil companies, such as BP, declined as they believe the auto manufacturers are simply trying to reduce their warranty claims."

BP has changed their mind and is now certified as top tier.
http://www.bp.com/en/global/corpora...oins-top-tier-detergent-gasoline-program.html

I think the problem that Costco has is that there are a variety of different additive packages used depending on what location the Costco store is at, and which local independent gas supplier they use. Even though the base gas stock is the same for every brand in a particular location (since there is usually only one or a few refineries in any area), each brand uses their own additives, but Costco cannot do that and they don't want to go through the expense and hassle of getting every different local supplier certified as top tier, since apparently some of their suppliers are not certified as top tier, either because they don't meet the requirements, or don't want to go to the expense of getting certified.

But I don't believe the automakers started the top tier program without good reason. They were seeing a lot of problems with fuel injectors, etc.

 

[medhat]

I recently just did a 600KM (372.82M) trip and got 6.9L/100KM (34.09MPG) and was traveling at 110KMH (68.35MPH)
Temp was 25C (77F) pretty calm winds.
This is by far the best I've ever gotten from my car.
I have a 2009 V8 and now have 125KM's on my car.
...
Car just purrs along and is still very smooth after more than 4 years of ownership!

FWIW I still love this car very much!!
...
Because I have NEVER put anything in my gasoline tank.
no techron, no cleaners, nothing.
I am guilty of having tried some 91 octane gas and maybe once or twice 94 octane and felt absolutely NOTHING!
99% is 87 octane gas...period

Kind regards,

That's exactly me as well. Because it says you can in the owner's manual, I've tried different octanes and followed MPG and subjectively power, and appreciated no noticeable difference. So back to Costco unleaded, no "additional" additives.

 

[landtuna]

At light throttle no detonation is detected. In town with heavier throttle acceleration detonation is more likely, which in turn causes ignition advance to retard, which reduces gas mileage.

Modern engines with ECU's operating properly should never experience detonation no matter what the fuel quality. The knock sensor will continue to retard the timing until knocking is no longer present. As timing is retarded gas mileage is reduced, as is power.

High octane gasoline burns slower than lower octane (under like conditions) and the slower burning is what delivers the "no knock" condition. Virtually all modern engines will use 87 octane with no problem although a minor increase in power can sometimes occur with 91 or 93 octane. Whether it is worth the added cost is up to the individual driver.

An engine knocking (the sound is more like a "tink") is in trouble and the operation should immediately be changed to eliminate the noise and the cause investigated. Serious damage to the pistons, heads and valves can occur should knocking continue for prolonged periods.

 

[wchettel]

....
I think the problem that Costco has is that there are a variety of different additive packages used depending on what location the Costco store is at, and which local independent gas supplier they use. Even though the base gas stock is the same for every brand in a particular location (since there is usually only one or a few refineries in any area), each brand uses their own additives, but Costco cannot do that and they don't want to go through the expense and hassle of getting every different local supplier certified as top tier, since apparently some of their suppliers are not certified as top tier, either because they don't meet the requirements, or don't want to go to the expense of getting certified.

But I don't believe the automakers started the top tier program without good reason. They were seeing a lot of problems with fuel injectors, etc.

It seems as if COSTCO now has their own gasoline detergent additive. Look at this page on their web site. It claims to be 5X the EPA detergent requirement.

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[Mark_888]

It seems as if COSTCO now has their own gasoline detergent additive. Look at this page on their web site. It claims to be 5X the EPA detergent requirement.

1. Even if it has 5 times the EPA requirements, it is "apparently" not Top Tier certified. Not sure what the difference is.
2. Costco gas with Kirkland Signature Clean Power detergent additives is available at "selected stations," so apparently not all Costco gas stations have Clean Power (although a majority probably do). They provide a link to identify which stations sell gas with Clean Power additives, and pumps with Clean Power supposedly have stickers to identify them.

 

[Mark_888]

...I have NEVER put anything in my gasoline tank.
no techron, no cleaners, nothing.

• I was not aware that there is an all electric version of the Genesis sold in Canada.
• Seriously, just about all gas has some form of cleaners in it. Techron is a proprietary name used by Chevron for their formula, and all Chevron gas contains some Techron (even without adding any extra Techron from a bottle). Likewise, other brands of gas contain similar additives to help keep fuel injectors clean.

 

[IBJanky]

I see now that Costco gasoline now states that it has top tier detergent additive. So typically I get 87 octane Shell, or 91 octane Costco but add a bottle of Techron every month. Maybe this makes this unnecessary? What think the list members?

Costco gas is fine. Your car won't blow up.

Save your money and use octane the manufacturer recommends. Skip the unnecessary Techron too while you're at it.

Drive more, worry less.

 

[Mark_888]

Costco gas is fine. Your car won't blow up.

Save your money and use octane the manufacturer recommends. Skip the unnecessary Techron too while you're at it.

Drive more, worry less.

Hyundai very clearly in the Owner's manual recommends 91 octane for its 4.6 and 5.0 V8 engines. But they say it also runs on regular gas with slightly less "performance." EPA testing is done with premium.

"For improved vehicle performance, premium unleaded fuel with a Pump Octane
Rating of 91 (Research Octane Number 95) or higher is recommended."​

Hyundai branded fuel injector cleaner (sold at Hyundai dealer parts departments) contains Techron and is relabeled Chevron Fuel Injector cleaner (exact same bottle shape/mold, same ingredients, etc).

 

[videopho]

Costco gas is fine. Your car won't blow up.

Save your money and use octane the manufacturer recommends. Skip the unnecessary Techron too while you're at it.

Drive more, worry less.

+1
And I have done so for the past twenty years for all of the cars I've owned.

 

[427435]

High octane gasoline burns slower than lower octane (under like conditions) and the slower burning is what delivers the "no knock" condition.

This is a shade tree mechanic myth. The reason that high octane gas is less likely to detonate is that it takes a greater combination of temperature and pressure for self-ignition.

Think about it-----------why would a racer want a slow burning fuel in an engine turning 8-9,000 rpm??

 

[landtuna]

This is a shade tree mechanic myth. The reason that high octane gas is less likely to detonate is that it takes a greater combination of temperature and pressure for self-ignition.

Think about it-----------why would a racer want a slow burning fuel in an engine turning 8-9,000 rpm??

This is a highly complex issue and I provided a very baseline answer. There are many reasons for a gasoline engine to knock and as many ways to reduce or prevent it. But the basic reality is that the combustion chamber designer does not want ignition of the compressed gasses inside the chamber to proceed the flame front. Doing so will cause the ping, or knock. Therefore, reducing the burn, or spread, of the flame front timing tends to reduce the chances of knocking. This is what I meant by "slower burning".

We are discussing knocking in passenger car engines under normal use. Racing applications are something else entirely. The same basic principles apply, however, more solutions are available to a racing engine designer due to removal of cost constraints and availability of exotic fuels.

 

[wchettel]

It's kind of funny how this thread which started out discussing the quality of Costco gasoline morphed into a discussion about the technical aspects of engine ping or knock.

 

[waveman]

It's kind of funny how this thread which started out discussing the quality of Costco gasoline morphed into a discussion about the technical aspects of engine ping or knock.

Technical discussions on the Internet often include pinging, so don't knock it.

 

[wchettel]

Technical discussions on the Internet often include pinging, so don't knock it.

AKA "Hijacking" the thread.