An SUV is really not a truck. Always get a chuckle out of that.
High octane will reduce engine knock, albeit miniscule. It will give you slightly more power and burn a bit cleaner. Does your manual say "required" or "recommended"? Higher octane will make small differences over time. If you are keeping your "truck" for the long-term, you might benefit from slightly less wear and tear using higher octane fuel. Check out the article in Car and Driver on this subject. Depends on the car/truck as to whether you will benefit. All four of them benefitted in HP and MPG. Moreso in power.
Do what makes sense for you. Buy a $100k SUV and ***** about a difference of $500-$1,000 a year in gas to ensure longevity? Seriously? Sucks for the used car buyer getting a high mileage rig that ran on 87 its entire life.
Who am I to say, I take my brand new LX off-road.

 

You're wasting your money. IDC who puts premium in their trucks, I just refuse to waste money, down to things like this. Especially now since the COL has skyrocketed. I saw the C&D article. The 5.7 is a simple under-stressed truck engine not a Mercedes V12, nothing fancy about it except VVT-i which is 25 year old technology. It doesn't need premium fuel. You think the fuel in the Middle East where these roam is clean 93?

I picked up 9.5/10 condition 2014 LX570 a year and some change ago that had seven years of premium fuel, it's seen nothing but 87 since the day I bought it.

.....the engine hasn't blown. It doesn't knock, it hauls ***, and that's that. Nice to see a fellow owner take theirs off road, I definitely do as well.

And gosh how depressing, this is an old thread when gas was $2.

 

We continue to use ethanol-free 91 or 93 octane. The LX has used that for the last 120K miles with no issues. The Land Cruiser has around 60K with no surprises. I'd say "feeling" judgements are more of a slight brain derail v. anything factual. Given what Toyota says is a 5 hp or so difference, at rpm redline, I't say differences are all in your head.

I've been on mud for around the last 10 years. I have yet to see an engine failure due to the use of a lower octane fuel v. what Toyota recommends.

If you've seen a failure due to octane, I'd love to see it.

 

I would not do it with these tires and wheels. I replaced my wheels with 18" Land Cruiser wheels and AT tires the first day I brought it home from the dealer.

 

I bought a new set of Tundra 18" take-offs from a dealer...new lug nuts and caps too. I mounted Toyo AT2's and the truck is now running Toyo AT3's.

OEM tires are definitely designed for on-road only, and that's on very good roads. No downside to an on-road/off-road tire. Little if any freeway groaning, better in the rain. Better wear. Definitely better on fire roads.

 

Did you keep the old ones? I'd like to get another set but keep the Lexus rims, they're way too good looking to get rid of. If you never had any fun with the 20s on, I can tell you it's still plenty capable with the 20s on. That said I want some Tundra rims too with fatter off road tires, to switch on and off.

 

21" factory wheel/tire is not ideal for off-road. The cool thing is you can still take it off the beaten path, over knarly trails, and is plenty capable. Not ideal. Waiting to put my 18" Tundra wheels on it but I was burning some tread over the Spring/Summer. This should not be able to do what I've done on 21's. I'm only saying it can and will blow your mind with how capable it is on a suboptimal off-road setup.

 

I don't disagree entirely. However, you would likely never see the minimal wear/tear differences in the engine from running low octane longer term, unless you break the engine down. Speculative, although very intuitive. I much prefer to run cleaner, get a small HP gain and slightly better MPG. I tow a lot and I can tell you the difference in towing was noticeable in my Tundra TRD Pro. Same engine. You don't have to use 91-93. But I do after a few trips with 87 towing a large load years ago. It is subtle, but does exist. Most people wouldn't pick up on it. Most people don't really care. That's fine too. For me, prefer to run lean and clean, **** away some Benjamin's each year for peace of mind.

 

Higher octane, when under load (especially when towing), will less likely cause engine knock...due to the detonation timing. normal driving you probably won't notice much...maybe u get to drive further distance when using higher octane fuel. To me, I always put in premium.... 30 cents / gallon diff each time 17-18 gallon fill up cause a diff of $4-5, to me the diff in price is absorbable. Similar speaking, some ppl say you can put in 5/30 regular engine oil...despite the manual says 0/20 syn.... I only put 0/20 every oil change on 5k interval though.

 

I wouldn't worry about a speck of damage. If your Toyota performs better (or if you're saying it's "worse" without it) then why wouldn't Toyota ask for premium? Once gas goes down I am going to run some tanks of premium and scrutinize the hell out of my LX. After these $110 fillups who gives a flip about $5 extra for premium lol.

You could put probably any oil out there in that 5.7 and it would be fine. Gas too. This is my issue with the downsized turbo V6, I would be much more careful and vigilant. It's going to be fragile compared to the 5.7.

 

87 all day. Unless towing then I’ll run premium. It’s the same engine as the tundra and LC. Zero reason to put premium in.

 

I tend to trust the engineers who build these engines over a bunch of clublexus dudes. Personal preference. If you want to buy a $100k vehicle and skimp on fuel, get worse mpg and slightly lower HP, knock yourself out. I tow too much to **** and moan about 91-93 octane recommendations.

 

It is the exact same engine that went into Toyotas, identical in every single way. You’re trusting marketers, not engineers. It’s not a Mercedes V12. It’s a meat and potato truck engine that would drink rotgut, third world fuel and be fine, let alone 87 here in USA. Remember these roam deserts and jungles. Shell V-power 93 ain’t gonna be the gas they get.

Funny this thread has been brought up because I actually filled up with premium last tank (why not, my gas bill is already so sky high) and can tell absolutely zero difference. Nothing Nada Zip. I’ve tested it in every way possible, including abrupt, surprise full throttle a foot against a building to listen closely. Absolutely positively zero difference. It’s not my money but LX570 doesn’t need premium fuel. Complete waste of money. Using 87 when gas prices are normal mitigates the horrible city MPG because some competitors really do require premium so the cost ends up being about the same as competitors that get better mileage.

But if you want to spend even more when gas is already $5 a gallon knock yourself out!!! But what do clublexus dudes know? I eat sleep and breathe Lexus especially trucks (Toyo too) myself. FYI it’s stupid to fall for Lexus marketing, as a “ClubLexus dude”.

 

I tend to trust 91 to 93 octane, ethanol free. Towing or not towing.

 

5.7 will gulp down standard 10% ethanol gas jusssst fine.

It's the new ones I'm a little concerned with. I'd have to do a lot of research before trusting 87 octane in a downsized, boosted motor.