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- - AAA: Top Tier Fuel Study (https://www.ft86club.com/forums/showthread.php?t=108161)

Quote:

Originally Posted by Lantana frs (Post 2701315)

Re combustion chamber deposits: I didn't see afr or cr of test engine in pdf.

It was controlled via ASTM D6201, there's no need to publish those parameters as they adhered to the already published standard.

https://www.astm.org/Standards/D6201.htm

Edit: Apparantly the issue is covered on page 17 of the report, the other buildups are due to the extra detergent basically 'sticking' to the head.

Quote:

Managing intake valve and combustion chamber deposits is a difficult balance of quantity of detergent
and the appropriate chemical composition of the polymers that remove carbon deposits on the desired
engine components. If the chemical composition is incorrect, deposits can form on the injector, back of
intake valves, and in the combustion chamber. The concentration of detergent within the fuel must also
be balanced since a low detergent concentration could result in higher intake valve deposits. A high
concentration of detergent could potentially cause deposits to form within the combustion chamber
and/or lead to intake valve sticking.
Part of the ASTM D6201 test protocol is to measure the deposit thickness and weight of the carbon
deposits in the combustion chamber to verify that excessive buildup has not occurred as a result of
adding more detergent. It is noted that in the TOP TIER acceptance testing, fuels are also screened
against test scenarios for excessive detergent build up that could cause intake valve sticking and/or
excessive increase of combustion chamber deposits.

Considering this test proves that top tier 'washes away' old buildup, it's probably best to alternate high detergent and low detergent fuels to minimize buildup.

Oh and drive the piss out of it.

Quote:

Originally Posted by Lantana frs (Post 2701232)

Use good gasoline

The problem is which. We are bombarded with bull crap ads and is difficult to identify the good one.

Quote:

Originally Posted by Teseo (Post 2701319)

The problem is which. We are bombarded with bull crap ads and is difficult to identify the good one.

Imo individual gas stations play a real life role as well; how old is the gas you're buying from a low volume mom and pop? Its been so hot here that my car feels like a mid sixties bug anyway. Again, the racetrac 93 has not caused any red flags per my oft.

Am I the only one who thinks the study reads like an ad? A real study is pretty dry, this one reads like a full page ad with the non-relevant pictures and fluff that's included.

I don't know what the angle for AAA would be, but they work with The Alliance of Automobile Manufacturers who support the top tiers fuel initiative which is something that the big oil companies don't support. I'd like to know who paid to have this study done and why they don't address the INCREASE of certain deposits with the top tier fuels in the study. The study focuses very strongly on the dramatic decreases in intake valve deposits, but glazes over the increases in cylinder head deposits.

Quote:

Originally Posted by guybo (Post 2701352)

Maybe a bit, but keep in mind that this a release for general public. Even with the fluff and pictures some people here (car enthusiasts!) refused to read it. How many would read the actual study, with technical language, formulas, and dry language.

The cylinder head deposits are barely larger with top tier, though I'd expct more discussion of them.

What I am trying to say is that there may something going on here along the lines you are suggesting, but it does not seem too excessive. Not worse than any "independent" car test in a magazine

Quote:

Originally Posted by mdm (Post 2701370)

Don't get me started with car magazines! They are the most biased, bought and paid for "independent" reviews in the world.

Imo there are too many factors that could explain combustion chamber deposits. I just want to put the shit in my tank and not worry about knock.

Guys, page 17 discusses the combustion chamber deposits.

93 oct race fuels and redline seems more reliable then

Quote:

Originally Posted by Lantana frs (Post 2701421)

Imo there are too many factors that could explain combustion chamber deposits. I just want to put the shit in my tank and not worry about knock.

Exactly. I've never owned a car long enough to really care.

Now ... once I decide on a car that I will keep for a LONG time. I will let her drink the best sauce around.

Quote:

Originally Posted by Th3rdSun (Post 2701221)

No way I'm reading through all of that. Anyone have the Cliff's Notes version?

It's not hard to find what you need, especially since it's on the 2nd page...

Quote:

Key Findings:
1. The test engine operated on a TOP TIER gasoline averaged 19 times fewer intake valve
deposits than when it was operated on non- TOP TIER gasoline. (based on the ASTM D6201
test - TOP TIER gasoline averaged 34.1mg of deposits per intake valve versus non- TOP TIER
average of 660.6mg)
2. Based upon secondary research findings, long-term use of a gasoline without an enhanced
additive package can lead to reductions in fuel economy of 2-4%, drivability issues, and
increased emissions.
© 2016 American Automobile Association, Inc. 3
3. In most cases, carbon deposits can be reduced or removed from critical engine components
1
by switching to a gasoline that meets TOP TIER standards.
4. Approximately six in ten drivers (63%) believe there is a difference in the quality of gasoline
sold by retailers, yet only (12%) of drivers purchase gasoline based upon its detergent
additive package. The primary motivation for choosing a particular gas station is location /
convenience (75%), followed closely by the price of the fuel (73%).
5. Most TOP TIER gasolines do not cost significantly more than non-TOP TIER gasoline. The
average price difference between the TOP TIER and non-TOP TIER brands surveyed was
three cents per gallon over a 12-month period.

Toyota said 91,,then i fill my car with 91.
Its not a brain surgery. Do what the manufacture said.

considering I'm tuning and testing out the brands of gas in my city...this is an informative report! Reading it as I type...

Costco gas is good enough for me. They're always busy and usually get delivery quite often. Price is good and Top tier is a plus.

But I do believe in using good gasoline IMO.