A question about Costco gas additives

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I find it funny how the internet is rampant with the hatred for DI, but yet I personally don’t know a single person in real life who has had any issues with DI carbon buildup.
You probably don't know anyone with a Vw/Audi 2.0T.

my 2008 Passat had misfiring issues when there was too much buildup on the valves. But my 2016 Tiguan didn't have much issues because I was proactively using fuel injector cleaner with each fillup.
 
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You mean like what Lexus and Toyota offers?

Considering that it's been offered on certain lexus engines since 2006?

From what I understand, the benefits there aren't necessarily about dosing the intake valves with fuel mist. It's about higher efficiency at lower revs.

Jason Fenske of Engineering Explained breaks it down in his latest video. There are lots of benefits to both methods of fuel injection, and it turns out manufacturers can use either one (or both at the same time) depending on an engine's RPM range for maximum power or efficiency. For example, using port injection means the fuel can cool down the intake air before it reaches the combustion chamber, increasing air density and allowing for more fuel to be used, and therefore more power. Port injection is used at low RPM for better air-fuel mixing, which results in a more stable, efficient combustion.​
Direct injection, on the other hand, cools the air inside the cylinder, greatly reducing the probability of knock. This means the engine can advance timing and run more boost before running into issues. Direct injection is used at high RPM to cool the chamber at high loads and create the most power possible.​
 
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You probably don't know anyone with a Vw/Audi 2.0T.

my 2008 Passat had misfiring issues when there was too much buildup on the valves. But my 2016 Tiguan didn't have much issues because I was proactively using fuel injector cleaner with each fillup.
I had a couple colleagues with 2010-2012 Audi A4’s with the 2.0T, was that the same engine as yours? They ended up burning oil and Audi replaced the engines, I vaguely remember them saying there was an extended warranty coverage provided by Audi.

At what point is it a flaw of GDI technology? And at what point is it just a flaw in engine design? Other GDI engines seem to be motoring along just fine. 🤷🏻‍♂️
 
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From what I understand, the benefits there aren't necessarily about dosing the intake valves with fuel mist. It's about higher efficiency at lower revs.

Jason Fenske of Engineering Explained breaks it down in his latest video. There are lots of benefits to both methods of fuel injection, and it turns out manufacturers can use either one (or both at the same time) depending on an engine's RPM range for maximum power or efficiency. For example, using port injection means the fuel can cool down the intake air before it reaches the combustion chamber, increasing air density and allowing for more fuel to be used, and therefore more power. Port injection is used at low RPM for better air-fuel mixing, which results in a more stable, efficient combustion.​
Direct injection, on the other hand, cools the air inside the cylinder, greatly reducing the probability of knock. This means the engine can advance timing and run more boost before running into issues. Direct injection is used at high RPM to cool the chamber at high loads and create the most power possible.​
The reason why Toyota did it is for emissions, just like Audi, doing it for emissions, not due to prevention of intake valve deposits. The main point is combining direct and port injection is not novel technology. It's been implemented since 2006.
 
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The reason why Toyota did it is for emissions, just like Audi, doing it for emissions, not due to prevention of intake valve deposits. The main point is combining direct and port injection is not novel technology. It's been implemented since 2006.

There's already been ways to reduce intake valve deposits with durable materials that prevent the deposits from sticking to the valves. But certainly it's a good thing, but I don't believe that the hybrid port injectors are designed to put out a lot of fuel.
 
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I had a couple colleagues with 2010-2012 Audi A4’s with the 2.0T, was that the same engine as yours? They ended up burning oil and Audi replaced the engines, I vaguely remember them saying there was an extended warranty coverage provided by Audi.

At what point is it a flaw of GDI technology? And at what point is it just a flaw in engine design? Other GDI engines seem to be motoring along just fine. 🤷🏻‍♂️
MB doesn’t seem to have any problems with GDI. I’ve asked several Indy MB shops about it. They tell me they haven’t seen any issues.
 
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I've used Costco gasoline almost exclusively in my cars since 2014...Cadillac CTS Sport Wagon, Chevrolet Malibu 2.0T, Chevrolet SS 6.2, Cadillac CTS V-Sport, Ford F150 5.4 as well as a few others...both Regular unleaded (87) and Super unleaded (93) following the manufacturers recommendations...no issues related to fuel with any of these cars ever...YMMV of course

Bill
 
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My experience with Costco gas is as follows. I have an 18 Legacy and a 19 Impreza. Both cars have had Costco gas. The Legacy from what I can tell runs just fine. The Impreza, I took to the dealer for its first or second oil change and mentioned that I'm not getting the mileage that I should be and that the car seems jerky. They asked what brand of gas I used and I said Costco and they told me not to use Costco and they have a lot of cars in the shop having issues with Costco gas. This was about 1 1/2 to 2 years ago. So, I switched to BP then Shell and it got better. Not 100% better but better. Now at the present, I took my car in for a fuel pump recall and I mentioned again that the car is jerky and asked them to run some TSB for the CVT trans. The last I heard was one of the logs was weird but they didn't notice anything while driving it. Then I got a txt asking what brand of gas I use. I haven't heard back.

My friend has a 16? WRX and has a COBB access port (I know nothing about this stuff). He told me that he was using Costco gas and it was pulling timing and he switched to Shell and his results were much better.

I am NOT a car expert nor fuel expert. So, I wonder if there is some truth to this issue with Costco gas but for the life of me I don't get why. If it meets the octane requirements AND has the additives to meet the top tier requirements, then why is there an issue?

For the record, I am NOT knocking Costco gas. I use it in my wife's CR-V and my Legacy but neither are DI, only the Impreza is. I have used it in my 2001 S4 too and didn't notice any issues other than what is already wrong with the car.
I've noticed similar with my car. I stick to Chevron & have no issues. I didn't think too much of it as my car is a 99 with well over 300k mi...figured it just needs an actual off-the-car injector cleaning. Other cars I've had ran just fine filling up at Costco. Gf's Civic runs fine on it as well.
 

CKN

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I've noticed similar with my car. I stick to Chevron & have no issues. I didn't think too much of it as my car is a 99 with well over 300k mi...figured it just needs an actual off-the-car injector cleaning. Other cars I've had ran just fine filling up at Costco. Gf's Civic runs fine on it as well.

I tow a 5,000 pound travel trailer-no matter what gas the 5.3 gets in it still pulls at elevation just fine. BTW-when you tow and get between 10 to 12 mpg I find the absolutely cheapest fuel.
 
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I woul ignore anything the guy at any dealer says.
Fixed.

IMO, you’re much less likely to get a bad tank of gas at a high-volume station. Costco is the better of them. Safeway sells the EPA minimum so I microdose with Red Line SI-1. I think you have a higher chance getting a bad tank at a name-brand station next to a high-volume but cheaper one.

If you top off past the first click, yes you risk EVAP system damage and a CEL if not gas all over your car.
 
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Costco doesn't make gasoline. They buy it on the spot market and it's supposed to be commodity grade the same as what most others get. Shell doesn't even have a single refinery left in California, so I'm sure that none of the fuel we see at our local Shell stations is made by Shell because they don't make California RFG any more. They likely do horse trading with other companies to deliver fuel somewhere else where they have refineries, or even buy it on the spot market to supply their franchises.

However, who knows where Costco gets it. It's different in every location. It probably changes too because Costco is so price sensitive. And in the end they just get it delivered at some fuel terminal just like most other gas stations with base fuel coming from the same tanks.

I can't account for what someone does with a tuned engine, but certainly it's possible that the octane rating of certain fuels is higher since the pump sticker only specifies minimum octane rating. I would never rely on it. Every refiner has periods where they have to shut down for maintenance or due to accident, and then they have to buy fuel on the spot market.

I'm not quite sure what incentive any company would have to vastly exceed the requirements given the way that fuel is distributed - mostly by pipeline operators as a commodity. Everyone make commodity fuels for the most part. While I doubt they really want to cheat, there's no incentive to far exceed the requirements (which costs money) when most of your output is just going to someone else and likely mixed with the same commodity grade from other refiners.
Shell does not have any refineries in California, would there be a change in their additive package?
 
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Shell does not have any refineries in California, would there be a change in their additive package?

I've mentioned that before, as the Shell (formerly Equilon) refinery in Martinez was Shell's first American refinery and their last one in California. Obviously that didn't kill the Shell brand in California. But all it would take is loading the additive at each fuel terminal that might deliver to Shell stations. That's done automatically and each one would get its own additive tank.
 
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I tried Costco Premium Gas back in 2019 in my 2006 TSX. I was using the car to commute 45miles each way. I noticed a strange or different smell coming from the exhaust during warm-up and my mileage dropped enoughf for me to switch back to Chevron or Shell.
 
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I’d like to know what’s in the additive? Sounds like it’s identical epa approved stuff that everyone uses. If so there’s no special sauce just the amount of sauce.

Also what is the mix ratio and how much extra does it cost per gallon of gas to get the 5x concentration?

Not really. Costco's materials claim that they had Lubrizol make a custom series of additives just for them. That doesn't really seem all that unusual. I'm sure someone makes the additives for Shell. BP's "Invigorate" additives are listed on the EPA website as made by BASF. Chevron lists Techron, but Chevron Oronite lists a bunch of generic additives that I'm sure get sold to different customers - many of which are Chevron's retail competitors. There's no particular reason to do it, as it's easy enough to just buy an off the shelf additive that meets Top Tier requirements and just slap a name (or not) on it.

But the general idea is that an additive may be "scalable" to meet different requirements depending on the concentration. This mentions "LAC" which means "lowest additive concentration".

HiTEC® 6590’s patented technology was designed to meet the challenges of direct injection engine technology, while continuing to deliver excellent performance in the traditional port fuel injection platform. A fully scalable additive with EPA and TOP TIER™ certification, HiTEC® 6590 delivers powerful keep-clean and clean-up performance at cost effective treat rates.​

Recommended Dosage​

HiTEC® 6590 is EPA, LAC Final Rule and TOP TIER™ certified. Please contact your Afton Chemical representative for specific recommendations.​
 
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