Why LC more expensive than LX? (1 Viewer)

[studio19atx]

With all due respect bloc, please stick with your firefighting.

I didn't go to school all these years, spend huge investments of time and learning, tuning turbo Lexus and Porches, develop new calibration for aircraft engines, to formulate an inconsidered opinion.

Everyone of your points is inconsequential fact to octane requirements.

Software (i.e. calibration) is its own animal, independent of hardware. I could build a tune for any number of engines that would require it to use 85, 91 octane, or 100 octane. Without a hardware change whatsoever. Fortunately, good engineering always accounts for people to mis-use systems, so there are safegaurds to protect as Lexus has likely done.

talking of software I would imagine ECU to have ability to sense the octane level and adjust t

I will let you guys know if i have any problems running regular, no point in fighting over it here and getting off topic.

I accept responsibility for the potential consequences of me being wrong here and worst case scenario i will end up with a freshly rebuilt engine XD and be out about 6k. I haven't had any issues so far but have not put enough miles on it to really know (183.5k currently!).

i highly doubt anything will happen to your engine , I would hope that the modern ecu are programmed to be adaptive to different formulations. When I used lower octane gas in my other Lexus, the difference was felt mainly in acceleration but there was no knocking. However, this could be placebo effect too.

 

[bloc]

Thanks, I couldn't have said it better myself. Do you want to join the layman club and eat crayons with me while we watch paint dry?

I've happily been in the layman club for a couple years now. This comes from being able to admit what I don't know. I've found it a valuable trait.

If you continue with this, be prepared to have more words put in your mouth (like both of your posts so far on the topic).

FYI the fruit flavored markers had better nutritional value.

Edit: there's a certain beauty in someone requesting you not post assumptions as fact when that is PRECISELY what they are doing.

 

[SharpeCat]

Remember it takes 2 fools to have an argument, or sometimes 3!

If we can't be civil, then it's best to agree to disagree before we end up saying more things we may regret later. I know i have done the same many times and wished i hadn't.

 

[TeCKis300]

talking of software I would imagine ECU to have ability to sense the octane level and adjust t

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.

 

[OregonLC]

Well, at least this thread went well.

 

[SharpeCat]

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.

So at 300k miles and 15mpg we are talking 20,000 gallons, which at .50 per gallon difference, equals $10k is gas differences. A rebuilt 3UR-FE is 5k plus labor is $1k, so for $10k i can pay for almost 2 rebuilt engines and labor.

I don't argue that it has a negative effect on the engine and that in turn will affect engine life, i just don't picture it affecting it to a point where it would require engine replacements often enough (every 180k miles @ 15mpg = 12k gallons = $6k) to justify the higher cost in gas. I feel that this is especially true for me since i did not start it on RUG until about 182k, or 1500 miles ago.

Do you have reasons to believe that running regular vs premium may cause a freshly rebuilt engine to die before reaching 180k? If not then i think i will take my chances, especially considering that the engine already has 182k, so even if the impact over the next 100k is as significant as you imply, then it still wouldn't be a bad run for this engine even if it dies out around then. Again, i have a tough time picturing that the impact would be that significant, but i am no expert on this matter.

If i were to be honest, i run it because my dad suggested it, and that is good enough for me. If it turns out that we are both wrong, then i am okay with admitting and accepting responsibility for it, and from there go with the recommended premium for the next engine.

What i won't do, is allow my mistake to become the next owner's problem, nor do i plan on there being a next owner for this car unless it is to a friend/family. I do see where you are coming from though and i appreciate you trying to educate me on the matter/make sure i don't make a costly mistake.

 

[slipkid13]

So you are going to squirrel away the .50 cent per gallon difference at every fill up for 300K miles and magically have 10K sitting around to rebuild your engine?

Again, I don't understand this mentality. If you are so tight on money that .50 cents a gallon is something to fret over then why are you even driving a vehicle that gets 12-17 mpg and costs way more than most other vehicles/SUVs

 

[tacoduck]

Meh, I drive a nice as hell LX570. I put 87 in it. A lot. I honestly cant tell a difference. Ive heard of zero engine failures in LX or LC. The engines is darn near bulletproof. If it was a high dollar twin turbo AMG, then I get it. LX470 was the same way. Cheap gas. 10k oil changes, truck took it all with a smile.

 

[SharpeCat]

So you are going to squirrel away the .50 cent per gallon difference at every fill up for 300K miles and magically have 10K sitting around to rebuild your engine?

Again, I don't understand this mentality. If you are so tight on money that .50 cents a gallon is something to fret over then why are you even driving a vehicle that gets 12-17 mpg and costs way more than most other vehicles/SUVs

Did you consider that i paid 18k for mine, and that it already has 180k on it? If i had 100k to spend on a car, then i wouldn't fret over the difference in gas prices. Unfortunately for someone like me who makes 15 bucks an hour and had to dig really deep to find one in my budget, that i do very much have to weigh the pros and cons of everything in terms of cost; including when it comes to regular vs premium.

Also, i was using 300k as a reference, the actual cost is 6k if i needed to rebuild and pay for labor. That 6k is a potential cost, as in maybe i have to pay it if worst case scenario happens and i blow my engine within the first 180k solely due to the reason that i am using regular gas. No one has explained to me how the damage is so significant that regular gas will kill en engine capable of 300k+ easy within 180k, so chances are unlikely that i will ever have to pay that 6k before the savings in gas prices makes up for it. One is a "potential/maybe cost" and one is a "real cost".

I may not have 6k sitting around, but i promise you if it came down it and i needed an engine then i will find 6k really quick. Most people don't have money sitting around for a house, but when they need one they find a way, don't they? I will deal with it when the need arises, don't you worry about that. I just don't see it getting to that point any time soon though, she really is running smooth still. Like i said i will keep an eye on it, report in and keep everyone posted. I have no problem with being wrong and admitting it if i am, but some things i have to see for myself, i guess. Thanks for trying anyhow.

 

[OregonLC]

So you are going to squirrel away the .50 cent per gallon difference at every fill up for 300K miles and magically have 10K sitting around to rebuild your engine?

Again, I don't understand this mentality. If you are so tight on money that .50 cents a gallon is something to fret over then why are you even driving a vehicle that gets 12-17 mpg and costs way more than most other vehicles/SUVs

There's never justification to simply waste money. Would I still choose to daily the 200 if it got 10 mpg vs 12? Probably. But that would be a case of something I can't control. Making the informed decision to use less expensive fuel when there really aren't any documented downsides (other than the owner's manual) is, in my opinion, being a good steward of one's financial resources. $10k is a lot of money to waste regardless of how great your income is or how much you paid for your truck.

All theory aside, there is no empirical evidence pointing to 87 being harmful to the 3UR. Nor have I seen where the 3UR benefits from longer range when running 92 (as is the case with the 2UZ). For all we know, Lexus marketing felt it important to have HP numbers higher than Toyota, no matter how slight, and that the only reason behind the 92 reference in the LX is to legitimize the 2 HP gain.

Until there is documented damage from running 87 or documented mileage (range) improvement from running 92 this is all fruitless theoretical argument.

 

[studio19atx]

Meh, I drive a nice as hell LX570. I put 87 in it. A lot. I honestly cant tell a difference. Ive heard of zero engine failures in LX or LC. The engines is darn near bulletproof. If it was a high dollar twin turbo AMG, then I get it. LX470 was the same way. Cheap gas. 10k oil changes, truck took it all with a smile.

Was premium fuel recommended for 100 series 4.7 V8?

 

[studio19atx]

Did you consider that i paid 18k for mine, and that it already has 180k on it? If i had 100k to spend on a car, then i wouldn't fret over the difference in gas prices. Unfortunately for someone like me who makes 15 bucks an hour and had to dig really deep to find one in my budget, that i do very much have to weigh the pros and cons of everything in terms of cost; including when it comes to regular vs premium.

Also, i was using 300k as a reference, the actual cost is 6k if i needed to rebuild and pay for labor. That 6k is a potential cost, as in maybe i have to pay it if worst case scenario happens and i blow my engine within the first 180k solely due to the reason that i am using regular gas. No one has explained to me how the damage is so significant that regular gas will kill en engine capable of 300k+ easy within 180k, so chances are unlikely that i will ever have to pay that 6k before the savings in gas prices makes up for it. One is a "potential/maybe cost" and one is a "real cost".

I may not have 6k sitting around, but i promise you if it came down it and i needed an engine then i will find 6k really quick. Most people don't have money sitting around for a house, but when they need one they find a way, don't they? I will deal with it when the need arises, don't you worry about that. I just don't see it getting to that point any time soon though, she really is running smooth still. Like i said i will keep an eye on it, report in and keep everyone posted. I have no problem with being wrong and admitting it if i am, but some things i have to see for myself, i guess. Thanks for trying anyhow.

chance engine blowing due to low octane is extremely low. Bad/no engine oil or coolant are common reasons.

 

[40Man]

There's never justification to simply waste money. Would I still choose to daily the 200 if it got 10 mpg vs 12? Probably. But that would be a case of something I can't control. Making the informed decision to use less expensive fuel when there really aren't any documented downsides (other than the owner's manual) is, in my opinion, being a good steward of one's financial resources. $10k is a lot of money to waste regardless of how great your income is or how much you paid for your truck.

All theory aside, there is no empirical evidence pointing to 87 being harmful to the 3UR. Nor have I seen where the 3UR benefits from longer range when running 92 (as is the case with the 2UZ). For all we know, Lexus marketing felt it important to have HP numbers higher than Toyota, no matter how slight, and that the only reason behind the 92 reference in the LX is to legitimize the 2 HP gain.

Until there is documented damage from running 87 or documented mileage (range) improvement from running 92 this is all fruitless theoretical argument.

If I had to guess, I'd say more likely due to the extra weight (and already lower MPG rating) Toyota decided to test the Lexus with the premium to eek out any extra mpg they can and/or to create a premium engine feel for a premium vehicle by requring... (wait for it)... premium fuel! I do know that many ECUs have multi fuel map parameters to adjust to safely run on multiple octanes without issue. Unfortunately, no one has done so for the LC.

 

[OregonLC]

Was premium fuel recommended for 100 series 4.7 V8?

The 2000 that I had and the 2004 that my wife drives both recommend 91 but state they can operate on 87. The 2UZ has been well documented in the 100 forum as benefiting in range (mileage) when continuously running 91. The hitch is that it's not financially beneficial. You pay more than you gain. In the 2000 that I had I would run 91 if I knew I was going to be pushing range. The extra 10 miles doesn't seem like much unless you're right at the limit.

 

[tacoduck]

Was premium fuel recommended for 100 series 4.7 V8?

yup. I ran 87. Ballin on a budget.

 

[slipkid13]

There's never justification to simply waste money. Would I still choose to daily the 200 if it got 10 mpg vs 12? Probably. But that would be a case of something I can't control. Making the informed decision to use less expensive fuel when there really aren't any documented downsides (other than the owner's manual) is, in my opinion, being a good steward of one's financial resources. $10k is a lot of money to waste regardless of how great your income is or how much you paid for your truck.

All theory aside, there is no empirical evidence pointing to 87 being harmful to the 3UR. Nor have I seen where the 3UR benefits from longer range when running 92 (as is the case with the 2UZ). For all we know, Lexus marketing felt it important to have HP numbers higher than Toyota, no matter how slight, and that the only reason behind the 92 reference in the LX is to legitimize the 2 HP gain.

Until there is documented damage from running 87 or documented mileage (range) improvement from running 92 this is all fruitless theoretical argument.

Driving a vehicle that gets 12-17 MPG is the definition of wasting money. If you drove a vehicle getting 20 mpg then you save 15K over the theoretical 300K miles.

Once again (with a few exception) I read about folks on this forum dropping BIG money on LCs/LXs and mods. 5 figure money but premium gas is where the budget line in the sand is drawn. It's laughable.

I don't care what you put in your truck but trying to justify saving $10 a bucks a fill-up on a near 6 figure truck, with most likely 5 figures worth of Mods, getting 12-17 mpg is dopey.

 

[OregonLC]

Driving a vehicle that gets 12-17 MPG is the definition of wasting money. If you drove a vehicle getting 20 mpg then you save 15K over the theoretical 300K miles.

Once again (with a few exception) I read about folks on this forum dropping BIG money on LCs/LXs and mods. 5 figure money but premium gas is where the budget line in the sand is drawn. It's laughable.

I don't care what you put in your truck but trying to justify saving $10 a bucks a fill-up on a near 6 figure truck, with most likely 5 figures worth of Mods, getting 12-17 mpg is dopey.

Driving a 12 mpg vehicle is a waste of money only if it doesn't provide you value. If it provides value it's not a waste.

Paying for high dollar fuel is a waste because it provides no value. If it provided a value (longevity, range, etc) it wouldn't be a waste.

 

[TeCKis300]

So at 300k miles and 15mpg we are talking 20,000 gallons, which at .50 per gallon difference, equals $10k is gas differences. A rebuilt 3UR-FE is 5k plus labor is $1k, so for $10k i can pay for almost 2 rebuilt engines and labor.

I don't argue that it has a negative effect on the engine and that in turn will affect engine life, i just don't picture it affecting it to a point where it would require engine replacements often enough (every 180k miles @ 15mpg = 12k gallons = $6k) to justify the higher cost in gas. I feel that this is especially true for me since i did not start it on RUG until about 182k, or 1500 miles ago.

Do you have reasons to believe that running regular vs premium may cause a freshly rebuilt engine to die before reaching 180k? If not then i think i will take my chances, especially considering that the engine already has 182k, so even if the impact over the next 100k is as significant as you imply, then it still wouldn't be a bad run for this engine even if it dies out around then. Again, i have a tough time picturing that the impact would be that significant, but i am no expert on this matter.

If i were to be honest, i run it because my dad suggested it, and that is good enough for me. If it turns out that we are both wrong, then i am okay with admitting and accepting responsibility for it, and from there go with the recommended premium for the next engine.

What i won't do, is allow my mistake to become the next owner's problem, nor do i plan on there being a next owner for this car unless it is to a friend/family. I do see where you are coming from though and i appreciate you trying to educate me on the matter/make sure i don't make a costly mistake.

Looking at this from a financial perspective might be useful for the pocketbook, but like many things, why do we indulge in an 200-series when a used Nissan might do. Or invest in a roof rack, when the stock one will do. To this topic, using premium is not all poured down the drain. The case for premium can have more to do with efficiency often, than power. Which is why there's been a movement in the auto-industry in the last decade towards premium, even in lesser cars, as they chase MPG numbers. The LX likely requires premium to compensate for its added weight over the LC.

Higher octane fuels may actually have less energy content than lower octane. Octane is a measure of resistance to uncontrolled combustion. Where it pans out is by allowing more timing advance (dynamic compression), to better extract what energy content there is in fuel. This is governed by the software calibration independent of hardware.

Do I believe running regular may kill an engine before reaching 180k?

How are you using your vehicle? Plodding along, it probably won't care, which is why so many believe it's okay.

Tow a heavy load, on a hot day, climbing a grade, using a bad batch of 87 octane, with a worn engine, and it may not. Knock sensors are a mitigation to these variables. Mitigation does not make for a good control strategy. One can choose to use the mitigation everyday to get by with 87 octane by riding the knock sensor, slowly adding microscopic deposits, etching, and fatiguing the combustion chamber. Then that mitigation strategy may just very well come up short one day.

I apologize to everyone if they are offended by the word layman. The negative connotation was not the intent. It was only to say that people are making strong recommendations to others without specialized knowledge on this topic. Just as everyone of us has our areas of expertise, I wouldn't try to step into someone else's domain and tell them how to put out a fire for example. That would make me a layman on that topic.


From the horses mouth:

Per Lexus LX 570 instruction manual, p 684.

"Premium unleaded gasoline only"
"91 (Research Octane Number 96) or higher"

p 692:

"If 91 Octane cannot be obtained, you may use unleaded gasoline with an Octane Rating as low as 87 (research octane number 91). However, use of unleaded fuel with an octane rating lower than 91 may result in engine knocking or drastically reduce output to protect itself while driving a heavy load. Persistent knocking can lead to engine damage and should be corrected by refueling with higher octane unleaded gasoline."

p 692:

"Premium unleaded gasoline with an octane rating 91 or higher required for optimum performance."

If there were a money saving strategy that I would adopt for the LX, is to perhaps use 89 everyday. 91 only for heavy use. 2 points of octane is probably within the margin of safety. 4 points is a pretty big stretch. Timing numbers from the ignition maps I have tuned in various vehicles vary dramatically between 87 to 91, which would definitely cause an engine to ride the knock sensor on load.

 

[Rando Kuruza]

Wasn’t this a thread about why the Lx is cheaper than a land cruiser lol...

anyway I agree with teck. Your car will not run as good on 87 as it does on 91... Ughhh when your engine senses knock is retarding timing and adjusting fuel ratios for sure it’s going to effect power and performance... how much, ughhh I don’t know??? sure wish someone would just go dyno their suv on both 87 and 91 so we can stop arguing over octane already... but what makes more power a spark before dead center, a spark at dead center, or a spark substantially after dead center... it’s just science

But I will tell you this in the 5.7 it has so much power are you really going to tell a difference?? Probably not. On my 05 470 when trying to crest a mountain pass I can really tell a difference with 87 vs 91... that old 4.7 liter doesn’t have a ton of extra power.

That being said I throw 91 in both my vehicles.

When I had a 2016 Ford F-150 Platinum that recommend 87 I put in 87...

just remember prior to knock sensors...if you put in the wrong octane your engine would just blow up... so does octane make a difference yes. 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.

 

[slipkid13]

I would hardly call an extra .50 cents "High Dollar, it's not 100 octane racing fuel. I can't definitively say it doesn't provide any value as I don't have 300K with 87 on my LX nor have I driven 10 tank fulls with 87 to see if my mileage changes. Of course if measuring value is equal to "I dive Land Cruiser" then that seems a pretty poor measurement.

I assume most folks are paying by CC for gas. So if you pump in 15 gallons are you really noticing or thinking about the extra $7.50 it cost you? It's the psychology of purchasing we fret over small prices and don't give a 2nd thought to large purchases because the money doesn't seem "real" $2.80 vs. $3.30 for a gallon of gas is real. We look at that .50C and can immediately calculate the difference.

$58,750 vs. $59,600 doesn't have the same psychological effect because the numbers are big enough to seem theoretical. (most) folks are not counting out 100 dollar bills when making purchases like that. Same with a house purchase, I hear folks moaning all the time about the $400 title fee or whatever on a 450K house they just indebted themselves in for life. Makes no sense.