jeffinthebag

All gas is the same basic recipe. The only difference is the chemical adjectives that get mixed in when filling the tanker truck. The tanker truck is partitioned inside for different grades. Back in the day using top tier gas definitely reduce the carbon build up internally. Maybe some one more recent can chime in. I have pulled apart a engine in 20 years.

All Hat No Cattle

FWIW, I don't know exactly where you are, but the Costco in Clifton, NJ is $2.69 today. And you get a 4% Cash Rebate if you use a Citi card. another $.10 off.

Kind of makes screwing with a recipe academic.

https://www.gasbuddy.com/Station/3096

As for Costco Top Tier quality, I would imagine that there are shyster lawyers salivating over the opportunity to file a suit for Costco's "bad gas". The only complaint I have is that no matter when I go, Costco always has a freaking line. So people are voting with their wallets.

jag1886

I guess I'm lucky, I only use a tank full every 3-4 weeks and I buy the good stuff. But then again on my truck it's only $5 difference between the cheap gas and good gas. I wish I could buy your gas at $2.89 a gallon, the good stuff here in Boise is at the very cheapest is $3.19 at Costco.

moparado

Correct^
I once worked in the petrochemical industry and just about all gas whether low or hi tier is produced by the same major refineries.
Different additive recipes are blended in per customer requirements.

I primarily use low tier 87 octane gas for years in all my vehicles including my 5.0 with no issues.
Once or twice a month i do fill up with upper tier gas and throw in some injector cleaner.

ifallsron

Curious if there's a way of telling the in-tank quality and ethanol content for any given tank mix.

GMC to Ford

TOP TIER gasoline has been proven to reduce carbon deposits and reduce engine related issues, including poor fuel mileage, and it has been documented in numerous studies. The additive package has to meet stringent requirements to qualify as TOP TIER. The base stock is the same regardless of the store or name brand on the pump. Gasoline from different manufacturers is blended in the distribution chain, so the ability to claim you run Shell gasoline went away in the 1970s when independent distribution chains existed. However, it is the additive package that makes the difference.

One example from AAA published several years ago:
https://newsroom.aaa.com/2016/07/aaa...created-equal/

More detailed information on the same study: https://www.consumerreports.org/car-...h-extra-price/

An important point is that the automotive industry (Ford is one of them) developed the TOP TIER standards and testing program to reduce engine related warranty claims and lower emissions. I highly doubt that the auto manufacturers would have spent money on TOP TIER development without a monetary incentive, so it must be effective.

sdmartin65

Early eighties worked in petroleum industry in Phoenix area. When Texaco tanker loaded at the rack the additive was added by hand then fuel loaded for a splash mix. Little more hi tech today the additive is injected while loading. So if Costco splash blends additive at the station it would work just fine. An eight thousand gallon load only needed couple gallons of additive but it is some caustic stuff to handle.

All Hat No Cattle

We are the proof of that in Vegas. For years, we only had one gas/diesel pipeline between Southern Cal and Vegas. I always wondered how they separated regular, diesel, and premium in one pipe. We have finally gotten a second pipe from Salt Lake City.

Mark Miller

Right on about the mixing of 87 and 93 to make 89 I talked to a tanker truck driver years ago and he told me the same thing!And thanks for the tip on running 93 octane in my 2017 3.5L Eco Boost truck it was worth a tenth and over a mph at the track in worse weather then when I ran 87 octane!!

moparado

Petroleum pipelines are a fascinating technology having worked on one for a few years automating and installing SCADA computer equipment.

The pipeline companies inject huge rubber spheres into the pipeline to separate different fuels right before a different fuel is detected upstream in the pipeline.
At that point there will always be a small amount of mix between the two different fuels called the interface.
The interface mix is diverted into a slop tank by switching valves to be reprocessed later by a refinery. Timing is everything in the process.

The pipeline company i worked for used multiple 800 to 1500 hp electric pump motors at each booster station along the pipeline with a max flow rate of 8000 barrels/hr @ a max pressure of 300 psi. Though they normally operated below those limits.

People with petro pipelines near or on their property don't know what they're sitting on..