Hey Scottie, I have seen your videos about this that premium is a rip off and run regular.
Just curious with the new 3.5L 11.5 to 1 compression piston do you still think that I can run regular unleaded gas 87 octane and the computer will compensate for the lower octane and not damage the engine?
It recommends “Premium gas”.
It is recommended, not required.
THank you Yaser
If the car calls for premium gas, you want to run premium gas 100% of the time to prevent engine knocking amongst other things. If it calls for regular gas, run that.
Cheaping out on gas when you buy a $50k+ dollar car makes zero sense. Use the gas recommended by the manufacturer. Everybody has an opinion on fuel, but unless they were on the engineering team that built your motor their opinion is irrelevant. If you use low octane in a car that calls for premium and you have an issue, the dealer will void any warranty repairs. And no, you cant just fill it with premium before going in as the PCM will record the octane tables and the fuel switch will be visible to the technician.
Bottom line: Do what the owners manual says. Some cars like Mustangs say you can use any grade, but premium for best performance. Some are premium only and usually say it on the fuel door, gas cap, or gauge cluster.
Mod man I am a mechanic and engineer. I just wanted an "experts" opinion. Thank you YASER
I asked for facts not opinions
Oh ok. Sorry bud. I worked for GM as an engine builder and currently own my own exotic/performance car dealership and build custom cars from NOTHING for people. EXCUSE ME for treading on the toes of a "mechanic" who has to ask what octane to use in his car. I'm glad printed data, included with every automobile from every manufacturer ever made, is not "fact". You didn't ask for facts. You just wanted someone to give you some justification that you are right. And you're not. Any idea how many people's cars I have had to fix because some guy ran regular fuel in his Ferrari and can't understand why he has an engine issue? At any rate, I say run whatever you want to bud...may as well throw whatever weight oil you want to in as well. By your own logic, what does the manufacturer know? People like you keep people like me in business, so thank you. Ask a question on a forum and serve up attitude when you hear something you don't like from someone with more experience than you. You'll go far.
Very well said @mod_man ! I hate it when people try to go against the manufacturer specifications to save a few extra cents. You bought an expensive car, and a performance one at that! Why would it even cross your mind to put a lower octane than what's recommended? You should have bought a Toyota or something if you really want to buy regular gas honestly.
When I had my Mustangs, I always used premium fuel. In those cars, the manual states it is ok to burn regular, but for best performance burn premium. I know I didn't pay for a near-500 HP car to not get the best out of it. As you said, it cost something like 20 cents or so more a gallon. If you have to split pennies that much, you need to buy a different vehicle. You and I are 100% the same opinion on this. As usual on most things I've noticed. Haha.
@mod_man
Haha, probably because we use our own experiences to make a point, not "hear say". I've experimented with octane before on my BMW. It recommends AT LEAST 91 octane or HIGHER. That's exactly what it states for this topic writer's car as well. Anyways, I wanted to see how the car would run with 87 octane...and sure enough it ran like crap to the point the engine light turned on for knocking. You learn things by experimenting around, and we were being nice enough to help this person out without suffering any potential consequences of running regular gas. Experience is always better than "hear say". Some people on this forum don't value our experience unfortunately and always want to argue with "technical facts". Thanks for sharing your experience btw, that's awesome!
Thank you very much for your input, Mod_Man. We appreciate you taking the time to answer this question and helping out.
I looked up the 2020 GS350 owners manual on the Lexus site in regards to the octane requirement.
page 519 under 8.1 specifications
Says...wait for it.....91 octane (research octane number 96) or higher
https://drivers.lexus.com/t3Portal/document/om-s/OM30J07U/pdf/OM30J07U.pdf
This is recommended not required. Although if someone wants to throw his money away, it is another story.
Why people fight the manufacturers requirements for fuel I will never know.
because people that save money build wealth
I'm just a car driver and don't know crap but every written instruction I ever saw had two choices. Like for oil weight they "suggest" to consider the condition the oil is used under. The same for gas grades. Octane can vary because of use. Hard driving asks for more octane. "easier driving" can allow for lower octane. If manufacturers deny warranty then they must also have some way to prove your driving conditions. For instance did your kid drive the crap out of the car when you put low octane in? Or, did you tow higher than recommended weights with high octane?
Instructions are lawyereese to save someone money. Find another lawyer to protect yourself. Use of gas is as optional as color.
IF you wanted to SAVE money you should have bought a Prius...
@jimz
You're comment is not true...whether you're driving easy or not you need the same required octane at all times. Driving easy or hard does not change the combustion inside the engine. It's the same amount of air, the same amount of fuel, the same amount of compression involved in the combustion process each power cycle.
If it calls for premium gasoline (91/93 octane), I wouldn't suggest running regular gasoline (87 octane). Higher octane gasoline is important for performance engines like that. Switching to a lower octane will give you less power and may even cause knock. Octane rating is not a gimmick.
If you want the maximum horsepower of your car, use premium gas, but you do not need for normal driving and your car computer will adjust for lower octane gas without any harm to engine.
sMerry Christmas Yaser! Thanks for the very quick reply! Not concerned about horsepower only reliability. I did not know 89 or 87 octane would cause any predetination to the pistons. It is great if if will not cause any harm to the engine if I use lower octane gas.
As I said, it won’t cause any issue.
Does the owners manual state specifically Premium is recommended not required ?
Exactly my point...recommended usually means required in terms of octane ratings. The only car I have actually seen use different octane ratings is Mazda's turbocharged engines. And who doesn't want to maximize the engine's full potential anyways? It's just $0.20 more for higher octane. My opinion.
All I asked was would it cause damage to the engine. I did NOT ask about the performance. Naturally anyone would know that an engine will not perform as well as high octane. I can read specification and RECOMMENDATIONS. I was asking Scottie for his experience. I did not need opinions or recommendations, I just asked a simple question. Thank you Yaser for your response very much appreciated.
Does Lexus say gasoline or ethanol will damage the engine? I could see more damage from ethanol than from octane ratings.
@jimz
Ethanol is used in pump gas at stations to increase the gasoline's octane rating...you don't get pure gasoline or pure ethanol at gas stations.
I found a video from Scotty with his opinion regarding premium fuel in a Lexus
https://www.youtube.com/watch?v=ouT-wkMeTa0
some time ago and I don't drink that much kool-aid now, you would get a small packet of cherry kool-aid and add your own sugar and water. Add more sugar for more sweetness. This may change the taste of the cherry kool-aid but the cherry flavor is still the same (almost) concentration. So appearances are deceiving in gasoline also. 87 octane in some states is 85 octane with ethanol added to average out to 87 octane. So, this type of averaging is completely elementary. The gas is still 85 octane. You dont want 85 otane gas in your car.
@mfgmarques
Nope, there is a BIG difference between octane ratings...to the point where using 87 octane in a turbocharged engine requiring 91 octane WILL cause knock.
https://nortexlubeandtune.com/2018/01/16/happens-put-regular-gas-premium-car/
"People who save money build wealth."
Here is one for you: "Don't spend a dollar to save a penny."
I'm going to say this one more time because it is talking to a wall at this point, but: YOU WILL, 100%, ABSOLUTELY, POSITIVELY DAMAGE YOUR ENGINE OVER TIME IF YOU RUN LOW OCTANE IN A VEHICLE THAT REQUIRES HIGH OCTANE. I don't know how many sources need citing for this to sink in. I see it all the time, but there's always "that guy" who says "Nope. saving $500 over a 5 year period will make me a millionaire and I WILL NOT put premium fuel in this $50k car I can not truly afford to maintain properly." Then I get $10k to rebuild his motor, which he puts on a credit card at 26% interest, so he can then drive the car straight to Carmax and sell the car he spent $50k on for $10k and go on preaching the ways of "How To Become Wealthy".
The damage is FACT. FACTS can not be argued or debated. So, continue to run Wal-Mart Regular in your Lexus and see what happens. A lot of us have tried to warn you. It is like someone who won't quit trying to touch the stove and you try to warn them. "Don't touch the stove. It's hot." "Hey, don't touch the stove." "Don't touch the stove." Until finally "Fine, you know what, lick it. Yup. Burns doesn't it? That's because it's hot."
See you in your next question thread: "HELP! Lexus Won't Start. Mechanic Says It Needs A Motor! (He's A Liar!)"
GS350 F sport 3.5 V6 DOES NOT REQUIRE high octane gas. This car is not an exotic car and I do not know anyone who owns a Lexus/Toyota with V6 engines and has issues because the premium gas has not been used in the car.
Don't bother @mod_man some people just never learn things or even take some advice. We've experienced it before, and I actually hope they experience it as well so they know what we're talking about. They think a scientifically established octane rating for gasoline is a joke and obsolete for the function of an engine. Let's ask this question...why is there octane in the first place lol?! Why bother if they all run the same right?! There's been like 10 posts regarding octane...they don't understand.
I think this discussion is starting to lose focus. It has been marked as solved so lets move on.
[ Topic closed ]
It's in the manual in plain English.
if it doesn't knock then what's the issue?
