arentz07

OK that's weird. If I click the link in the email about this message, the PDF opens right up. But if I click the link from Club Lexus in the browser, it asks me to join.

I'd say just Google "AAA top tier fuel" because that works for me. Or try copy-pasting the below:

https://www.aaa.com/AAA/common/AAR/f...ull-Report.pdf

(I suspect that Club Lexus's redirect link isn't playing nice with AAA's website.)

GoHorns

AAA study was a total of 6 fuels tested (3 top tier/ 3 unbranded). And it did not report a p-value for statistical significance. They did not actually test fuel consumption, emissions, or power production.

The only benefit from the additive pack from top-tier fuels that was shown by the testing was on intake valve deposits. The top-tier fuels, on average, had worst cylinder head deposits, and similar piston top deposits. So out of the three things measured, only one showed a benefit, and one showed a detriment.

The engine used for the test was a Ford 2.3L port fuel injected engine because of a design flaw: "the orientation and temperature of the intake valves accelerate intake valve deposit formation."

So how is this testing conclusive that top-tier fuel is actually worth it and not just a marketing exercise? The IS500's engine lacks the design flaw that the Ford engine had.

https://www.aaa.com/AAA/common/AAR/f...ull-Report.pdf

If using top-tier gas gives you piece of mind, go ahead and keep paying for and using it. But to say that not using it is going to cause engine problems is a big stretch.

Contamination of a storage tank can happen at any gas station. Buying "top tier" fuel has nothing to do with that. And contaminated gas is the problem the dealer is claiming I have. Just trying to find out if the codes the dealer gave me actually indicate contaminated gasoline.

arentz07

Look, I know we're way off topic here, but I don't understand how you can ignore the significance of cleaning the valves. They are the last thing the air touches before it's in the combustion chamber and an obvious point of disruption for the air. I am not an engineer, but from what I understand about intake valve deposits, they can, in many cases, cause engines to run rough and lose power, requiring walnut blasting or some other cleaning. At that point, was saving the money on the non-top-tier fuel really worth it? The difference in intake valve deposits is staggering. It's not a small number where writing off the other benefits is even warranted. Statistical mumbo-jumbo or not, the difference is obvious and considerable. You can't fluke a 90% reduction. There is clearly a reason for the Top Tier certification.

Having said that, I'll occasionally take my car to Kroger to top off with plebian, non-Top-Tier gas just because I know I can get away with it and use my discount. It saves me a few bucks here and there. I only go once in a blue moon so my discounts don't expire, but still. I'm not saying you have to subscribe to the religion of Top Tier gas, nor should you. However, this study shows that even starting to use Top Tier fuels after some time can still clean off existing deposits on the valves. If you're really concerned about cylinder head deposits, then maybe just... do like I do and run both normal and Top Tier fuel in some combination.

The point is, if I want to buy a nearly-$70,000 car, I am not going to risk the injectors or valves getting gummed-up prematurely because I am not putting the best gas with the best additives in my engine. It's the same reason why I am switching to full synthetic oil and no longer using the Toyota Genuine Motor Oil that the dealership will provide me by default. It's the bare minimum to keep the warranty, but I am not a bare minimum customer. I take the car on spirited drives and road trips. I run it to redline on a regular basis. If I would do these things knowing they have long term consequences, I would be foolish to not at least try and compensate with proper maintenance. That's my whole point. I won't go into the nuances of oils or fuels any further, as honestly, all I can do is offer anecdotes and references.

Bechtold

In my area the QT and Costco gas is top tier and generally not the most expensive gas. They tend to be the lowest priced or close to it. So in my area there is no additional expense for it.

I would say the AAA study is 7 years old and could have tested a few more engines for a better sample pool.

flowrider

iTrader: (9)

Well, I guess I worship at that alter Nothing goes in my truck except Top Tier Regular and in my LC, Top Tier Premium plus Lucas Octane Booster. Here in Arizona we only get 91 Octane Premium My KCLV numbers are three of four points higher with the Lucas product

GoHorns

Update: Dealer cleared the codes and drove it around. Codes did not come back. No charge from the dealer.

Pittsy

I know this is completely unrelated, but why is this?

I mean, why does the 2UR call for conventional motor oil instead of synthetic? One of the team leaders at the dealer I work at mentioned it to me, and I knew of what he was talking about, but I'm curious as to why...

This probably deserves its own thread...

arentz07

It's a synthetic blend, for whatever that's worth.

Pittsy

did they put enough oil in your motor?

arentz07

Just checked, looks good to me. It went up a little past the top fill line. Why?

edit: Oh, I see the qty of "7.0", hrm, that is weird.

Probably way off topic lol. I posted in the oil change thread.

Pittsy

yep, calls for 9.1qts, you were billed for 7. As long as it looks right. But yeah a bit off topic lol

arentz07

I've moved all the most recent posts about oil to the oil change thread. Let's continue this conversation there.