Interesting article in Costco Connections magazine: https://www.costcoconnection.com/may_2024/page9.html
Costco upgrades Top Tier Fuel
- Thread starter Frankrank
- Start date
It was TT before-now is it “Super” TT? If it helps with GDI deposits, it’s worth it, but who’s going to be the guinea pig?
Going back to the AAA Fuel Quality Report from 2016: Yeah, there is a difference in Top Tier fuel brands when it comes to performance.
From the study, fuels 4, 5, and 6 were Top Tier fuels.
Fuel 6 exceled at reducing intake valve deposits, with fuels 4 and 5 having 4-7x more deposits. Not to worry, the non-Top Tier fuels had 57x more intake valve deposits, so all the Top Tier fuels were significantly better than the non-Top Tier fuels.
Looking at piston deposits, the opposite was true: Fuels 4 and 5 revealed less piston depots and fuel 6 had more.
All three are Top Tier fuels, but some detergent packages appear to trade performance on intake valve deposits for increased performance when dealing with piston deposits.
As it is, you have no idea what detergent package you're getting at any Top Tier station. So, yeah, I can absolutely see blending a detergent package to better suit the deposit characteristics of a GDI engine now that the majority of new engines have gone down the GDI path and advertising it as a competitive advantage like Costco is.
From the study, fuels 4, 5, and 6 were Top Tier fuels.
Fuel 6 exceled at reducing intake valve deposits, with fuels 4 and 5 having 4-7x more deposits. Not to worry, the non-Top Tier fuels had 57x more intake valve deposits, so all the Top Tier fuels were significantly better than the non-Top Tier fuels.
Looking at piston deposits, the opposite was true: Fuels 4 and 5 revealed less piston depots and fuel 6 had more.
All three are Top Tier fuels, but some detergent packages appear to trade performance on intake valve deposits for increased performance when dealing with piston deposits.
As it is, you have no idea what detergent package you're getting at any Top Tier station. So, yeah, I can absolutely see blending a detergent package to better suit the deposit characteristics of a GDI engine now that the majority of new engines have gone down the GDI path and advertising it as a competitive advantage like Costco is.
Hermann
Site Donor 2023
Does it mean more ethanol is in the blend.
That test is not a proper test because they didn't use the same base stock gasoline with different additives. The base gas is going to affect the deposit formation as much as the detergent is.
They likely get the fuel from local suppliers, but you can typically see their additive tanks next to the little office by the pumps. They have been using Lubrizol for their additives. I'm not sure if that is the case now. I've been using their fuel almost exclusively for several years now. I have no complaints. I also have nothing to show whether it's better or worse than anything else.
I understand that. They are buying the oil and slapping their name on it. Are they buying the additive (made for others-as well) and touting the marketing? Sorry if my post wasn't clear.
They use a proprietary additive that Lubrizol makes for them to their specs.
JHZR2
Staff member
Good points, but this has been discussed for decades. Certainly at least since the late 90s when I got. Y license.
The theory is that different additives and detergents are good at removing certain things. But even those can leave their own residues too…. Which is why conventional,theory was to change fuels, change additives, use a maintenance dose versus high dosing, etc.
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Me too. About all I have to show is the savings. But if we were to go back to 2007 and the car forum, people told me filling up at Costco? I don't deserve to drive a BMW. Amazing how at any given point in time, there are those who know everything, and are condescending when it comes to our habits, and how they compare to their own. Even today! Even here!
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Where I live Costco is always 10-30 cents less per gal than other stations. Are you saying $4.95/gal is more than other brands, or are you illustrating how much more you have to pay where you live
In Phoenix, price at my Costco is usually same or up to ten cents cheaper than my cheapest nearby option. If you have Costco Citicard you get four percent back on Costco gas with the Executive membership and only one percent for non-Costco gas.
No I don't usually look elsewhere as Costco is always cheaper. So based on previous experience I would expect other stations to be a nickel to a quarter more. Also commenting on the price, when CA is trying to tell people how great things are here.
Hermann
Site Donor 2023
It's $2 less a gallon here.
