Poll - LX570 owners using regular 87 octane or Premium (1 Viewer)

[Markuson]

My 2-2004 and my 2005 LX's all were Premium "recommended" not "required". 2015 LX states "required"

My 1999 LC was Premium “required,” actually.

 

[Chocolate]

Hmmm. OK. But what do you say to cases like my 100 series...that went from 60k miles to well over 200k miles on 87 when it required premium in the same language as the 570...with not s single fuel or engine issue when it was sold at 230k?

My case had zero effects even at 16 years old and high mileage.

It just doesn’t seem to cause the slow/long term damage many are claiming.

Only 230,000 miles? Check again at 500,000 miles for the regular wear!

 

[Markuson]

Only 230,000 miles? Check again at 500,000 miles for the regular wear!

Ya, somewhere there’s someone still driving it... Should ask him...

 

[SWUtah]

My 1999 Land Cruisers owners manual states 87 Octane required. That's what I ran. Based on owners experience looks like 87 octane has not taken its toll on even high mileage 91 Octane required LX570

 

[Markuson]

My 1999 Land Cruisers owners manual states 87 Octane required. That's what I ran. Based on owners experience looks like 87 octane has not taken its toll on even high mileage 91 Octane required LX570

Mine required it...complete with a “Premium ONLY” label inside the fuel door...plus this in the manual:

 

[Romer]

I run regular unleaded 85 Octane in Colorado and have no issues. I tried running premium and mid grade and saw no difference in MPG or performance. I know the computer adjusts a lot

I used to have everyone in the house do at least mid grade because of the extra fuel injection cleaners and someone told me or I read that with quality gas there really isnt a difference in injectors

Now I accidentally put mid grade in a BMW I had and the engine was having fits so that require premium

The land cruiser is built for the world market and the extra stuff Lexus says isnt needed where the parts are 100% the same like the drive train

Just my humble opinion and your mileage may vary

My owners manual says 87 octane which is the same as 85 Octane in Denver due to the elevation

 

[Romer]

From one of the many threads on this topic I recall Toyota changed the owners manual from 91 to 87 octane with no change to the drivetrain some time previous to my 2014

 

[Markuson]

I run regular unleaded 85 Octane in Colorado and have no issues. I tried running premium and mid grade and saw no difference in MPG or performance. I know the computer adjusts a lot

I used to have everyone in the house do at least mid grade because of the extra fuel injection cleaners and someone told me or I read that with quality gas there really isnt a difference in injectors

Now I accidentally put mid grade in a BMW I had and the engine was having fits so that require premium

The land cruiser is built for the world market and the extra stuff Lexus says isnt needed where the parts are 100% the same like the drive train

Just my humble opinion and your mileage may vary

My owners manual says 87 octane which is the same as 85 Octane in Denver due to the elevation

Ya, when I’m in areas where 85 is considered regular (like Colorado), I use 85. Similarly...no change in performance. In fact...before my rig got super heavy, and had only sliders, lift, wheels & ATs...85 was a big part of my highway trip to Wisconsin & back, where I averaged right around 19MPG despite a full load, and 520lbs of people.

 

[Romer]

Here is another thread/poll on the subject for more reading pleasure
87 vs 91 Octane: LC vs LX570

and another thread/poll
Quick Poll: LC 200-What Octane Do You Use?

And a tech thread with other good info
LC200 vs. LX570: HP, Torque, and Required Octane Ratings

 

[TeCKis300]

Hmmm. OK. But what do you say to cases like my 100 series...that went from 60k miles to well over 200k miles on 87 when it required premium in the same language as the 570...with not s single fuel or engine issue when it was sold at 230k?

My case had zero effects even at 16 years old and high mileage.

It just doesn’t seem to cause the slow/long term damage many are claiming.

The burden of proof is on you. Just because something is still running doesn't mean it's not degraded compared to one running premium its whole life.

 

[TeCKis300]

This is good to see that the ECM is good at protecting the motor. From an old post of yours - LC200 vs. LX570: HP, Torque, and Required Octane Ratings

There is a difference in redline FWIW in first gear at least in the LX where it will shift to second gear at 5,000 rpm at 87 octane, and will rev until ~5600 rpm in first with 93 octane. That's the only "noticeable" difference I can see. While the ECU in the LX will adjust for the fuel octane as posted above, I still use premium for the small difference in yearly cost and my driving style. Commute is only about 10-12 minutes usually, with a longer commute I might switch to regular.

I paid for the full capability of the LX. And I use it. For that, I'll pay for premium gas.

 

[Markuson]

The burden of proof is on you. Just because something is still running doesn't mean it's not degraded compared to one running premium its whole life.

How would I prove that? Buy another identical 100 and take the engine apart?

My “proof” is 230k miles on the odometer without a single engine or fuel related issue—which many here seem to say should manifest due to lower-than-required octane.

I guess I’m just wondering what all the hubbub is about if less than the “required” octane led to zero issues at 16 years of age and 230,000 miles.

When would you project the problems should arise...and how severe should they be? Honestly feel confused as to the perceived threat. Seems it must be pretty minor, or surely symptoms would develop, wouldn’t they?

I get the impression that the predictions of doom here seem to be primarily (if not exclusively) theoretical...and when given direct numbers (like mine) that don’t follow the theory, it’s declared invalid somehow. I dunno... Seems my miles, and trouble free, long-term use are being rejected. Suggestions?

 

[bloc]

Comparing spark plugs between RUG and Premium-fed LX570s would be one way to put this to rest. Or is this mini-knock too small to impact one of the hot spots in the cylinder?

[QUOTE="Markuson, post: 11693209, member: 35751”]I get the impression that the predictions of doom here seem to be primarily theoretical...[/QUOTE]

Exactly my issue, because none of us know whether there really are differences in “calibration”, let alone what those differences may be.

 

[TeCKis300]

How would I prove that? Buy another identical 100 and take the engine apart?

My “proof” is 230k miles on the odometer without a single engine or fuel related issue—which many here seem to say should manifest due to lower-than-required octane.

I guess I’m just wondering what all the hubbub is about if less than the “required” octane led to zero issues at 16 years of age and 230,000 miles.

When would you project the problems should arise...and how severe should they be? Honestly feel confused as to the perceived threat. Seems it must be pretty minor, or surely symptoms would develop, wouldn’t they?

I get the impression that the predictions of doom here seem to be primarily theoretical...and when given direct numbers that don’t follow the theory, it’s declared invalid somehow. I dunno... Seems my miles, and trouble free, long-term use are being rejected. Suggestions?

You're looking for a smoking gun and there is none. I will be the first to admit that I can't say for a fact, that you'll see an octane related failure, even in long term use. Most modern ECM's on vehicles, the fact that it's a Toyota/Lexus, and the fact that it's based on the legendary Land Cruiser, suggests that you can abuse the hell out of it and it'll still keep on ticking. Because that's what they do, they get you there. And back.

There's a huge grey area between optimal, acceptable, marginal, and degraded when it comes to engine performance.

Would I as a layman, without any understanding of engines, engine controls, calibrations, or even engineering in general, take it upon myself to second guess Toyota? With my $80k+ vehicle?

I am an engineer that oversees the design of complex systems including engine controls and reliability, and tune cars for a hobby. I get to see the results of failure mode analysis for engines, along with root cause assessments. I manage engineering teams to solve incredibly difficult problems that take millions in investments in time and resources to understand or even begin to reproduce a failure mode, let alone a solution. And work with tech writers and trainers to recommend best practices in manuals to end users. BTW, marketing comes no where near manuals.

The way complex systems are managed are with margins. Engineers build in safety factors not for the typical scenario of cruising down the freeway, but for the incidental situation of hot weather, on a 7% grade, for a not new engine with deposits, running a bad batch of gas. Get in the wrong situation, where all your margins and tolerance stacks go away, and you might not be so lucky. Except I don't call that bad luck. Engineers don't engineer with emotion.

All I can do is inform you layman on best practices. Much like gaijin would do with tires.

 

[Romer]

Toyota changed the owners manual to say 87 Octane, or regular unleaded. They wouldn't have done that if there was risk of damage to the engine. My manual says regular and the LX has the same drivetrain. Not sure how the laws of physics would change between them

and changing hats as the moderator I ask that everyone remain respectful of each other. It is ok to have disgareements. Its Okay if others dont believe the other persons position. We respectfully lay it out and ask questions. Asking someone to prove it isnt fair game in this type of forum so it's OK to disgaree

 

[Romer]

I agree with TeCKis300 that this is a gray area. I dont know how different programming of the ECU impacts this and I also am an Engineer dealing with designs of complex systems that have to work in space.

What real difference does it make as long as YOU are satisfied with the choice you make for YOUR vehicle. There is no perfect tire, we all have favorites and reasons why.

 

[Chickenmagnet]

85

• Chickenmagnet
• May 29, 2018

Here is 85 unleaded. 215 on half tank.

However after reading all the comments I have been convinced to run higher octane, most of the arguments are convincing. However some people are naturally conservative and I am one of them. The argument that you have money for a 90k rig and can’t afford the gas is wasted on me.

I have an Acura RL 08 that I’ve been running 85 in the past 40k miles with no notice in performance drop. I know they’re not the same but they have the same recs on gas.

 

[OregonLC]

At the end of the day, it was probably just to move the needle 0.01% on a CAFE calc that was needed to offset additional Tundra sales and has nothing to do with longevity. They just did it because they didn’t think a Lexus driver would balk at the premium fuel while marketing requires all Toyota’s to run on regular.

 

[Chocolate]

I wonder if a difference of 2 horsepower is even reproducible over dyno runs.

 

[FinallyGotOne!]

Toyota assembles the 3UR-FE right in here in Huntsville, AL. Maybe I should just drive up, knock on the door, and ask the question. As a group, we are having a great discussion, but no new and definitive information is emerging....

Then again, I don't think the LC/LX engines are sourced from here.