I tried to get an official answer from Toyota but it looks that they don't mind lying about this issue. Unfortunately, their answer is a complete nonsense. There may be a minor software difference in ECU, but I don't think so.


"Thank you for contacting Lexus Customer Satisfaction.
Despite engine specifications being similar to that of Toyota models, our current Lexus LX model was engineered to be a high octane gasoline engine. Octane is a measure of gasoline's anti-knocking properties. Knocking is a condition in which fuel burns too early in the combustion process, also known as "predetonation" or "pinging." It is the instability of lower octane gasoline that causes it to burn prematurely and unstably in a higher octane engine. The higher the octane, the more stable the gasoline, which in turn reduces knocking.
An important note is that high octane gasoline, which is more stable, has no more energy potential than lower octane gasoline. There is no more energy to be had from high octane gasoline, then from low octane gasoline.
Using low octane fuel in a high octane engine will result in severely reduced performance because the engine will attempt to adjust to the lower octane gasoline. In extreme cases, or with prolonged use of low octane gasoline in these engines, pinging or pre-detonation can occur and can eventually destroy your engine. Pre-detonation causes very hot conditions in your engine and can melt sparkplug and pistons.
Ultimately, our Lexus LX model's engine is designed for higher octane fuel for optimal engine performance and prevention of engine knocking, pre-denotation, and damage."

LX engine definitely was not designed as "a high octane gasoline engine". It was designed for Tundra/Sequoia and Land Cruiser. Although they are right, using low octane fuel in a high octane engine may cause severely reduced performance but not at this case. I would bet that the diffrence would be just 2 hp, which is the difference between Land Cruiser/Tundra/Sequoia and LX570.

 

Got to remember when you picked up your new LX, the dealer has filled the tank with regular as it is all they carry in their onsite tank.

 

I have never, rinse and repeat never put high octane fuel in any of my vehicles. 100% waste of money!

I have over 100K on my LX570, 35K on my GL550 and 60K on my CR-V. They all run as good as the day I bought them and I've never ever had an issue.

Today's vehicles have very complex fuel management system that monitors every millisecond of your engine running and adjustments are constantly taking place.

In the old days this was an issue as there was no such thing.

All of this is marketing between the manufacture and the fuel companies. You don't get any more or less mileage using the premium, mid-grade or regular fuel. It's all poppycock! Everyone's driving habits differ for many reasons.

 

Completely agree. 16 Land Cruiser I have just bought is rated for 87 and if you look at specs it has 2hp less than LX570. The difference is probably because LX was tested on higher octane gas. Lost of power is so small, that no one will ever notice, but with current gas prices you are saving at least 20% by going from 93 to 87. BTW I have BMW 435i which suppose to run on premium with its turbo charged engine. As well running on 87 without a problem.

 

I always understood that higher compression engines should use premium / high octane because of possible pinging.

However, the 5.7 is "high compression" but the tundra/other applications are fine with reg, so I guess I need to update my info or learn more!

I might venture a guess (after all, we are on the internet here my ignorance should be no object! ) that the high octane is a requirement when you are running at "maximum" to meet the published specs (of hp, top, speeds, towing). In other words, towing heavy trailers, or loaded to or near the max cargo weight rating, or running at extremely high speeds. But hey, really, how often is that happening, if ever?

I'm running premium for now, but I'm open. In my area we get some very low temps, I wonder if premium has any advantages to starting a low temps? Not that the LX has an issue, but my honda oddy is more sensitive to the very low temps...I should try to compare starting ability of reg v prem. Tough to get the comparison right, and tough if it doesn't work then the van is dead and wifey very unhappy!



J

 

If 87 is fine,it would be a plus for Toyota to recommend 87 in the LX but they don't.Why?

 

Probably just for marketing reasons. Premium car - premium fuel. But I would like to have this confirmed from Lexus, which of course will never do it...

 

Funny this came up yesterday while at the pumps at the local BJ's Warehouse store. I was filling up the Benz when the guy next to me was filling up his Hyundai Sonota.

He asked me what size motor was in the Benz. I told him a 5.5 liter V-8.

He asked if I liked the truck. I replied yes, but it's quirky on some issues and good on others and other than that I was pleased.

He asked why I was using regular vs. premium fuel. I replied it runs just fine on regular fuel and paying the 30 cents more per gallon was a marketing ploy. His reply was it has an aluminum engine. Aren't all engines of that type supposed to use premium fuel. No! Do you believe everything you read?

I told him this one has 35K, my Lexus has over a 100K and my Mitsubishi had over 250K and all ran fine on regular fuel. Yet the fuel door stated otherwise.

His reply, maybe it's quirky because you use regular fuel. Nope. It's because it does not support audio bluetooth and the fuel light coming on means fuel up now vs later! Neither one has nothing to do with the fuel type!

 

This is the first time I heard of this

 

Why does "why" even matter?

The engines are identical 3UR-FE's. Compression ratio on both is such that 87 octane will work. Were there an issue, you'd hear spark knock driving up a grade with the pedal to the metal.

After a few start-drive-stop cycles, the engine ecm should adjust the timing curve a bit.

Steve

 

I would also like to hear why from Toyota.
LX is the 3rd Lexus currently in my family and I also own 3 other Toyota vehicles now. I would like to know why Toyota wants me to spend more for the fuel than necessary. Why they lie to me in their answer for my question - they said that LX engine is designed for high octane fuel...

 

Why do they lie about premium fuel? Its all about maintaining luxury car segment image. Luxury car=premium fuel. Pure marketing

 

Yet other Lexus models that were premium are now regular.
I don't believe it's marketing.A regular fuel recommendation would always be welcomed by potential LX buyers.Especially with 13/18 MPG numbers.

 

And what else could be the reason? They are the same engines. There is no difference.

 

I believe premium was about $4 a gallon back when the '12 models of the ES and RX went from premium to regular...