Why LC more expensive than LX?

[OregonLC]

Now a days the questions is... do you care for the top performance of 91 for your suv? If not put in 87 save the money and enjoy.

The trouble is there is no real-world evidence of any performance delta. The trucks don't last longer, travel farther, or make you look better. Nada. So if the equation becomes 87 performance = 91 performance and 91 = top performance then 87 also equals top performance.

I think everyone here gets engine theory. The potential benefits of octane is proven science. What is unproven is that there is any measurable improvement in the 3UR. It's all theoretical improvement. You can be theoretically correct all day long but if it doesn't provide tangible results then it's not a theory worth worrying about.

 

[NYC570]

You're right. So let's follow this logic.

ECUs don't have sensors to directly detect octane.

Their primary sensor for ignition advance is the knock sensor. An ECU would sense and know to pull back timing by way of that knock sensor. By definition, that means there has been some instance of knock.

Knock is never good. Even low grade knock. Knock is uncontrolled combustion. Tends to leave deposits and wear combustion surfaces. Where further deposits like to form. Or where hot spots like to propagate from. Furthering the future likelihood of more knock.

Rinse, repeat. For 100,000 miles. How many knock events is that?

Don't worry, it's the next owners problem.

This is what people don't understand or as some here, don't really seem to care. For me it's about keeping my engine running at peak performance for as long as possible. 87 definitely won't give me that. I keep my cars for long so it isn't about wasting money but keeping my engine healthy.

 

[tacoduck]

Y’all probably use synthetic oil and change it every 3k miles as well because its “better for the engine”

 

[OregonLC]

For me it's about keeping my engine running at peak performance for as long as possible. 87 definitely won't give me that.

Other than theory what evidence do you have to support this?

 

[eatSleepWoof]

Running cost comparisons of extra fuel cost premium vs rebuilding engines is a pointless thing to do.

Rebuilding the engine also has these costs:
1. Being broken down on the side of the road. Best case, you're in your drive way. Worst case, you're a few thousand miles away from home, in the middle of nowhere. How much is that recovery/transport going to cost you? Cost of ruined trip?
2. Time and effort sourcing the engine. Do you happen to have these in stock at your local Walmart? I sure don't.
3. Time and cost transporting the broken vehicle + replacement engine to a shop.
4. Risk of having the shop do everything correctly. Cost of downtime.
5. Potential additional depreciation cost. I sure as heck would prefer to buy a vehicle with a well taken care of, original engine, instead of a rebuilt one (by god knows who and how).

Someone mentioned $6k to rebuild an engine vs $10k for extra fuel. Make that $6k vs $20k, and I'll still pick the $20k option, because the above hassle will have that much of a negative impact on my life. I bought a Lexus in no small part because it's consistently the #1 most reliable vehicle brand, and the LX570 specifically because it's the best of what Lexus has to offer. If I wanted to be rebuilding engines, I'd buy a turbo'd, 1995 civic from the neighbourhood boy-racer.

I don't have access to the ECU maps, and neither does anyone else. Until that changes and it's proven otherwise, I'm proceeding under the (very reasonable) assumption that there's a good reason the engineers that built this vehicle call for 91 octane. No, "it's just marketing" is not an acceptable argument. All of the "it runs fine on 87" comments are nothing more than short-term anecdotes in a very long-term game.

You do you.

 

[NYC570]

Other than theory what evidence do you have to support this?

Exactly my point, there's no proof of anything. The way I see it, I'm just going for the safer bet since there's no proof of anything. I do have experienced the effects of lower octane on other cars requiring premium but all cars are different. I also plan to do some testing to see if the LX benefits from running even higher octane like my other cars do. In my experience so far, Toyota tunes are very conservative, especially on hotter climates. If I lived at higher elevation all this of course would be different.

 

[OregonLC]

Exactly my point, there's no proof of anything. The way I see it, I'm just going for the safer bet since there's no proof of anything. I do have experienced the effects of lower octane on other cars requiring premium but all cars are different. I also plan to do some testing to see if the LX benefits from running even higher octane like my other cars do. In my experience so far, Toyota tunes are very conservative, especially on hotter climates. If I lived at higher elevation all this of course would be different.

I completely respect the notion of following the manufacturer's recommendations. Most people feel better when they do the 'right' thing. This is why some users obsess over not just running synthetic oil, but what brand will provide the absolute premium of protection for their baby. The truth is you can run any suitable dyno oil in it and the engine will still way outlast your ownership. I often fall into this mindset too. In fact I have four gallons of Mobil 1 75w-90 sitting on the workbench right now where I almost certainly would have been just as well off by using the Walmart brand for half the price (pro tip: Summit has gallons of Delvac for $35 shipped).

But after hanging around this forum for the last decade or so I've learned that the real issues start showing up as thread topics. I've yet to see fuel octane come up as a reliability issue in the 200. With as many 570s are in the wild and with the average fleet age at six years I have to believe we'd see at least one instance of a fuel octane related failure. There are none. Nor has anyone shown consistently greater mileage (or range) using 91.

 

[NYC570]

I completely respect the notion of following the manufacturer's recommendations. Most people feel better when they do the 'right' thing. This is why some users obsess over not just running synthetic oil, but what brand will provide the absolute premium of protection for their baby. The truth is you can run any suitable dyno oil in it and the engine will still way outlast your ownership. I often fall into this mindset too. In fact I have four gallons of Mobil 1 75w-90 sitting on the workbench right now where I almost certainly would have been just as well off by using the Walmart brand for half the price (pro tip: Summit has gallons of Delvac for $35 shipped).

But after hanging around this forum for the last decade or so I've learned that the real issues start showing up as thread topics. I've yet to see fuel octane come up as a reliability issue in the 200. With as many 570s are in the wild and with the average fleet age at six years I have to believe we'd see at least one instance of a fuel octane related failure. There are none. Nor has anyone shown consistently greater mileage (or range) using 91.

That no one has experienced problems with lower octane (and most likely no one ever will) doesn't mean that their engines are running at peak performance and this is what I'm after. I don't use higher octane because of manufacturer's recommendations. I run it because my experience with Toyota engines and tunes is that they're very conservative and even with 93 octane they don't run at peak performance in a lot of conditions, especially on hotter weather.

 

[LBridges]

All the back & forth on LX vs LC horsepower argument is somewhat interesting. I'm not an engineer of any sort (petroleum, automotive, electrical, etc), but as a retired physicist, I do still get curious every once in a while.

Here are a couple of things I found comparing a 2018 LC with a 2018 LX.

1) I looked first at ToyoDIY.com then online at Lexus Parts Now and Toyota Parts Deal. All three sites list the same Toyota part number (example: for 2018 that is 89661-60Y31).

2) Both the LC and LX factory repair manuals have exactly the same ECM installation procedure and do not reference any programming that I could find (I'm not the best at search, but I did look). I will admit that I did not research all the sensors, so the way the ECM reacts if there are different sensors, is still a valid question from my viewpoint.

Barring some other evidence I would conclude the extra ponies come from differing octane and resultant added ignition advance before the knock sensors kick in. I welcome a critique what I have above, what I failed to recognize, etc.

 

[bloc]

All the back & forth on LX vs LC horsepower argument is somewhat interesting. I'm not an engineer of any sort (petroleum, automotive, electrical, etc), but as a retired physicist, I do still get curious every once in a while.

Here are a couple of things I found comparing a 2018 LC with a 2018 LX.

1) I looked first at ToyoDIY.com then online at Lexus Parts Now and Toyota Parts Deal. All three sites list the same Toyota part number (example: for 2018 that is 89661-60Y31).

2) Both the LC and LX factory repair manuals have exactly the same ECM installation procedure and do not reference any programming that I could find (I'm not the best at search, but I did look). I will admit that I did not research all the sensors, so the way the ECM reacts if there are different sensors, is still a valid question from my viewpoint.

Barring some other evidence I would conclude the extra ponies come from differing octane and resultant added ignition advance before the knock sensors kick in. I welcome a critique what I have above, what I failed to recognize, etc.

I got curious about this very thing a while back.. I'm on good terms with the guys at the local parts counter and they told me that a new ECU for a 200-series landcruiser would need to be coded before it could be driven away. That said, I didn't look into the FSM procedures for actually doing so..

Things I can think of that probably do need to be programmed: vehicle VIN, immobilizer, any firmware updates that may have come out.

 

[slipkid13]

I think it is incorrect to dismiss 91 as "marketing" I have never heard anyone not consider a vehicle because it takes regular gas. I can't imagine Lexus engineers and marketing folks conspiring to require premium cause folks "expect" it. I would also guess that Toyota/Lexus built in some protection with the knock sensors assuming there are people ho refuse to believe that premium gas could ever be required because the LX is not "High Performance" Maybe you are right but i find it odd that the same folks take as gospel most of what else Toyota/Lexus says regarding maintenance but when it comes to fuel they are full of it.

I'll say (again) if you start worrying $$ over a 50 cent/gallon difference in a vehicle that gets 12-17 MPG and cost way more than just about anything else in it's class, well that doesn't make much sense.

 

[OregonLC]

That no one has experienced problems with lower octane (and most likely no one ever will) doesn't mean that their engines are running at peak performance and this is what I'm after. I don't use higher octane because of manufacturer's recommendations. I run it because my experience with Toyota engines and tunes is that they're very conservative and even with 93 octane they don't run at peak performance in a lot of conditions, especially on hotter weather.

What is your definition of peak performance if it's not measurable in terms of reliability or fuel economy? If the factory tune allowed for performance gains with octane we would expect to see it with increased mileage as is the case on the 2UZ. From what I can tell, that has not been demonstrated by those running 91 in the 3UR. So if the tune isn't taking advantage of the octane what peak performance is being missed with the 87?

Though see my comment on the last quote where I contradict myself a bit. So I will consent that if the 2 additional HP are because of the 91 octane then I would agree then that would be the peak. But that's like saying the top of the mountain is 87 octane, while 91 is standing on a step ladder and top of the mountain. I say that in jest because it's not much of an increase. But the 383 on 91 does give credence to your argument that 91 is the ultimate in 3UR performance.

I think it is incorrect to dismiss 91 as "marketing" I have never heard anyone not consider a vehicle because it takes regular gas.

The marketing isn't the premium fuel, it's the 383 HP that the marketing house wanted. Imagine the conversation in the Toyota R&D lab: "Hey Bob, what if we put 91 octane in? What happens to the power? It goes up to 383? Perfect, we'll use that on the LX".

Barring some other evidence I would conclude the extra ponies come from differing octane and resultant added ignition advance before the knock sensors kick in. I welcome a critique what I have above, what I failed to recognize, etc.

I tend to agree with this. At 91 octane in a lab they show 0.52% increase in HP (381 vs 383). Which lends credence to why we don't see any measurable fuel economy change. Assuming 12 mpg, this would be 0.0624 mpg change, not something you could measure. Though that also assumes a linear relationship between power and econ at partial throttle which doesn't happen in real life.

 

[NYC570]

What is your definition of peak performance if it's not measurable in terms of reliability or fuel economy? If the factory tune allowed for performance gains with octane we would expect to see it with increased mileage as is the case on the 2UZ. From what I can tell, that has not been demonstrated by those running 91 in the 3UR. So if the tune isn't taking advantage of the octane what peak performance is being missed with the 87?

Though see my comment on the last quote where I contradict myself a bit. So I will consent that if the 2 additional HP are because of the 91 octane then I would agree then that would be the peak. But that's like saying the top of the mountain is 87 octane, while 91 is standing on a step ladder and top of the mountain. I say that in jest because it's not much of an increase. But the 383 on 91 does give credence to your argument that 91 is the ultimate in 3UR performance.



The marketing isn't the premium fuel, it's the 383 HP that the marketing house wanted. Imagine the conversation in the Toyota R&D lab: "Hey Bob, what if we put 91 octane in? What happens to the power? It goes up to 383? Perfect, we'll use that on the LX".



I tend to agree with this. At 91 octane in a lab they show 0.52% increase in HP (381 vs 383). Which lends credence to why we don't see any measurable fuel economy change. Assuming 12 mpg, this would be 0.0624 mpg change, not something you could measure. Though that also assumes a linear relationship between power and econ at partial throttle which doesn't happen in real life.

For me performance means power delivery. If the 3UR Is anything like other Toyota V8s, the tune will definitely take advantage of higher octane.

 

[SWUtah]

It would be great if someone found the truth!!! I use Premium fuel and I alway use top tier brand fuel. I would love to save money like everyone else on Mud.

 

[40Man]

OrangeVirus has unlocked the ECU tuning for the Tacoma, Tundra RC 350 and others. I'm guessing since they did the Tundra and are working on adding the harrop sc as an option, they can do the LC and LX too.

Lexus recommends 91 octane in the RC 350, yet OV states that the stock mapping retards the timing to a very conservative level which robs performance. They have mapped a true 91 tune which gives over 10hp and 25 ft lbs (similar gain to many tunes I have seen with domestic vehicle premium tunes. The 2hp difference between the LX and LC leads me to believe it may be the same tune with general timing adjustment, similar to how the 2nd gen Toyota manual states to use regular or premium for enhanced towing performance, especially as Toyota is conservative for longevity.
OrangeVirus Tuning Lexus Stage 1 Reflash

And I stayed at a Holiday Inn Express last night.

 

[studio19atx]

Coming back to AHC part of the discussion, if cannot be easily removed or third party shocks be used, then leaving AHC alone, removing the running boards (covering with LC), will there be enough clearance? If I do end up going for LX, then I will probably install 18” Lexus wheels.

 

[studio19atx]

OrangeVirus has unlocked the ECU tuning for the Tacoma, Tundra RC 350 and others. I'm guessing since they did the Tundra and are working on adding the harrop sc as an option, they can do the LC and LX too.

Lexus recommends 91 octane in the RC 350, yet OV states that the stock mapping retards the timing to a very conservative level which robs performance. They have mapped a true 91 tune which gives over 10hp and 25 ft lbs (similar gain to many tunes I have seen with domestic vehicle premium tunes. The 2hp difference between the LX and LC leads me to believe it may be the same tune with general timing adjustment, similar to how the 2nd gen Toyota manual states to use regular or premium for enhanced towing performance, especially as Toyota is conservative for longevity.
OrangeVirus Tuning Lexus Stage 1 Reflash

And I stayed at a Holiday Inn Express last night.

Found this Which fuel grade should I use for my Lexus vehicle?
I could not find rationale as to why some vehicles are recommended 87 and some 91

 

[NYC570]

Coming back to AHC part of the discussion, if cannot be easily removed or third party shocks be used, then leaving AHC alone, removing the running boards (covering with LC), will there be enough clearance? If I do end up going for LX, then I will probably install 18” Lexus wheels.

According to a thread in here. The AHC can be removed. What's your purpose though? Will there be enough clearance for what exactly and why would you like to install third party shocks?

 

[Lou Gill]

I did the fuel comparison and in my truck the gas mileage decreased by 1-2 miles when using non premium in town....so we use premium and we have a Shell discount card (not a credit card) which saves $.05-$.10 per gallon on fill ups

 

[Rando Kuruza]

I just paid .30 more per gallon... and I feel great... I have never heard of anyone rebuilding a land cruiser engine

cost $3.60 to fill up and she runs great lol

I ran 88 non Ethanol fuel For a year and she ran great.

either way toyota engines are bomb so I’m never worried about rebuilding one lol