Premium Fuel Requirements Explained “Not Required”

[Code54]

The real question is how many fuel-related issues have you seen? Not from dirt, water, old gas, etc., actually the new, fresh gasoline fuel directly was the problem.
In modern cars, there are really very few damaged engines in the real world due to the actual octane rating of the gasoline. A lot of the time the issues that are "gas" related come from indirect sources. Poor storage tanks are a big one. Old gas that is varnishing causes a lot of the issues you hear about when someone says the "gas" causes an engine problem.

Also do you really think local dealers are draining tanks, sending it off to the lab to check the additive package and octane rating of fuel before a simple warranty claim? Sure a knock sensor could show a reading but there are a lot of reasons that can occur that are not the fault of the owner.

I personally think this 87 or 93 issue is overblown. The real question is did you test the fuel coming from the pump of your local station to KNOW it is exactly 93 octane? Who knows what is going on underground at the pump, especially when traveling and getting fuel at random places. If you didn't check it every time, did you void your warranty?

 

[GrayBeard]

@Teebo
Congrats on your new 1st Edition! Maybe since you have one you can post a copy of the fuel requirements from the owners manual? I trust David from AP but myself and others have posted pictures that show Premium Unleaded Fuel Only on the fuel door.

View attachment 1723

From the owners manual.View attachment 1725
Manual links: 2024 Toyota Landcruiser Manual Links

My fuel door and manual say exactly these as well, so it's pretty clear to me that Toyota is saying I should use AKI 91 fuel (with a RON of 96 the MON would be in the 80s, right? So the 91 has to be AKI, i.e. US Octane measure?)

My question then is, is there any definitive statement / document from Toyota that says the warranty will be voided if one uses a lower grade fuel? And if so, is there any way for them to tell beyond what's in the tank at the time you make a claim?

I've been running 93 exclusively (can't get 91 where I live) but would be willing to try several tanks of 87 or 89 to compare performance.

If there were no reduction in performance, or one that was outstripped by the savings in gas, and the warranty isn't at risk, it would be pretty tempting to just run the lower grade.

But from what I've read here, there are concerns about engine longevity if not using 93. I'm not criticizing that assertion, but have a question. In a modern engine that will retard timing to prevent lower octane knocking, what damage could occur to the engine from use of lower octane fuel? With the timing retarded, isn't it performing essentially as normal, or potentially putting even less power induced stress on the engine, at the cost of reduced power?

P.S. Hey Toyota, couldn't you just put an icon next to to the no Diesel icon that clearly states no AKI <91 if that's what you meant?

 

[doubleD]

But it still doesn't explain why the powertrain output (hp and torque) is the same for the Tacoma Hybrid and the Land Cruiser ...but the Land Cruiser "requires" premium but the Tacoma Hybrid does not (it's certified/rated on regular unleaded). There is still something funky about the setup—that they are different. I do agree with David...the Land Cruiser powertrain should be "safe" running on 87 but I still wonder what powertrain output (and fuel economy) is when running 87 vs. 91 (and 93) octane on the Tacoma Hybrid and the Land Cruiser.

I think this is fairly obvious when you look at some of the other choices Toyota has made with the LC.
There are fleet MPG requirements. And given how many vehicles on this platform are going to be sold, getting an extra MPG or two is critical to make the platform viable within their financial model.
The LC shipped with essentially road tires, a ton of engineering around the ECO drive mode, a non-optional hybrid power train with a tiny twin turbo four banger and premium gas requirement to hit their MPG target.
It’s entirely plausible that the Tacoma hit the mark without using premium gas due to other factors (weight, gearing, aero, tires, you name it) and therefore they elected to get slightly more volume out of the sales with lower running costs by suggesting regular gas. I think it is that simple. If they didn’t need the mileage of it, you’d probably see the same gas as the Tacoma. And my strong assumption is the EPA tests have you use what is posted on the gas tank door for the test.

 

[MSINAL]

David previously worked as a vehicle evaluation engineer at General Motors headquarters in Detroit. He is also an experienced automotive process engineer (he was the first employee of CAMI GM/Suzuki joint venture plant) and was a former Management Consultant specializing in Supply Chain.

Process engineer and specializing in supply chain does not make anyone expert on piston engines just because they have a you tube channel.



David if you are reading this i live in same city as you and would love to share my 35 years of piston and jet engines overhaul knowledge and manufacturing process. Difference between 87 and 93 and we can also talk about 100/110 LL.



Follow manufacture recommendations not you tube or google mechanic

Bingo! I wont reveal what i do for a living..ugh..NDAs.. .so process engineers have nothing to do with designing machinery, nor could they in my experience. Not saying this person is not the guru, may very well be, but process engineering has absolutely nothing to do engine design and tuning.
Besides, it's you against the dealer when things go south. Showing up with a youtube video won't likely help your case. If you follow what the owner's manual states you cant go wrong.

Study this book if you want to understand what is happening in your combustion chambers

 

[jambo]

Bingo! I wont reveal what i do for a living..ugh..NDAs.. .so process engineers have nothing to do with designing machinery, nor could they in my experience. Not saying this person is not the guru, may very well be, but process engineering has absolutely nothing to do engine design and tuning.
Besides, it's you against the dealer when things go south. Showing up with a youtube video won't likely help your case. If you follow what the owner's manual states you cant go wrong.

Study this book if you want to understand what is happening in your combustion chambers

Process Control and Automation:
Process engineers develop and implement control systems to monitor and regulate processes, often using advanced automation techniques.
Troubleshooting and Improvement:
They identify and resolve problems in existing processes, implementing solutions to improve performance.


He is a you tube engineer not a piston engine engineer.

 

[kmershly]

What I would not give for a diesel here in the states! At least here, no such thing as premium diesel, only winter or summer variants.

Thanks GM, you destroyed diesels in the States.

In my opinion, a roll of the dice if not using Top-Tier fuel. Sure, generally it is acceptable, but one bad tank can ruin your day. I notice, in addition to being Top-Tier, Costco now has an even better additive package.

A buddy of mine is a Powertrain Engineer for BMW AG in Germany.

In Europe, they don't have Top Tier, however, most brands do add the right amount of detergents required to keep the engine clean and operating properly.

However, my buddy also adds that if one wants, throwing in a Fuel Cleaner Treatment twice a year like Liqui Moly Jectron can makes up for gas with less detergents.

 

[jaray]

I was told at a dealer that the LC is said to require premium because it’s a global vehicle and alot of other countries fuel standards are not what ours are in North America. So they slap the premium sticker on to avoid people putting some pretty low grade fuel in.
Either way, the computers job is to retard timing to prevent engine knock. There’s no good reason why you can’t run 87 in them just fine. Throw a tank of premium every now and then on a long trip and don’t worry about it.

 

[TakaraLC]

I was told at a dealer that the LC is said to require premium because it’s a global vehicle and alot of other countries fuel standards are not what ours are in North America. So they slap the premium sticker on to avoid people putting some pretty low grade fuel in.
Either way, the computers job is to retard timing to prevent engine knock. There’s no good reason why you can’t run 87 in them just fine. Throw a tank of premium every now and then on a long trip and don’t worry about it.

What markets outside of NA the iforcemax variant is offered? I have seen this explanation before, but not sure it makes much sense since this configuration is only used in NA market.

 

[jaray]

What markets outside of NA the iforcemax variant is offered? I have seen this explanation before, but not sure it makes much sense since this configuration is only used in NA market.

Good point. It sort of sounded like an answer from someone who needed to have an answer rather than admitting he didn’t really know. So I think that throws that one out the window because I believe NA is the only market with that engine.

 

[wwoodywood]

Until someone can definitively post how the LC iForceMax engine differs from the 4Runner iForceMax engine that takes 87, I’ve got to assume we’re all getting played by a sticker and some fine print in the manual. (I’ve only ever put 93 from Sam’s Club or Costco in my LC, but 87 here is about $0.75 cheaper per gallon and it’s tempting…)

 

[cvx5832LC]

30k or thereabouts on regular. I switch to premium on overly hot days as a safety precaution because of all the hubbub on this board. If there is a difference, neither the truck nor my butt can feel the difference