Octane Levels

>tfw you drive a golf

Where do you live that 87 octane is E25??? The highest I've seen anywhere I've been in the US is E10 for Regular/Midgrade.

>If $300 is a game breaker in your life, you need to sort your shit out or stop getting starbucks every goddamn day.
This, or stop eating avocado toast

But if using 87 octane doesn't cause knocks and only sees a drop in performance numbers, why wouldn't you use 87 on the daily commute and then fill it up with 93 when you're ready to hoon?

You don't have the right to bitch about it when you could've just gotten a different car that is made for lower octane fuel.

Generally a decrease in performance is also accompanied by a decrease in fuel efficiency. One of my Miata friends reports that he only gets around 23MPG with regular fuel no matter how he drives, but gets 25-28 when using the recommended 91 octane (he owns an NC). In addition to uncucking your engine and not risking damage, it winds up costing about the same if your car behaves this way.

If your car does NOT suffer a marked decrease in fuel economy/performance/etc this way and also does not ping, the only other thing to consider is whether it is still under warranty. A manufacturer is not likely to replace your engine if it fails and you were consistently using the wrong fuel, especially since it's not hard to tell if an engine knocked itself to death.

If none of these things are a concern, or you just don't care and want to poorfag around, by all means use whatever fuel you want.

It's really fucking simple guys. If the owner's manual says it takes premium, then give it 91 octane at minimum unless higher is specified.

Putting a lower grade fuel like 87 in a car requiring premium puts your engine at risk of damage over long term. Yes the knock sensors back timing off, but you are still putting more stress on the engine by using the incorrect fuel.

My car can run on regular gas. However, it causes knocking and will slow the ignition timing. So to get the full use of my engine I use 93 octane fuel, that way it revs smoother and I can actually use the full powerband where all the power is. Plus, the extra additives will keep the engine healthier.

Sometimes this doesn't tell the full story. A car manual could say to use 87 octane and the car will run but what it doesn't say is that at higher rpms the car will have knocking issues. At that point, use higher octane fuel.

Also, lower octane gas burns hotter, which seems counter-intuitive but whatever, so running the cheap stuff in an engine that recommends premium will lead to more problems in the long run due to increased engine wear.

Higher compression or boost is more power. It's just the price you pay.

>But if using 87 octane doesn't cause knocks and only sees a drop in performance numbers, why wouldn't you use 87 on the daily commute and then fill it up with 93 when you're ready to hoon?
because thats not what the engine was designed for

Also you'll get worse performance and worse mpg because of it.

Can't you put RON 95 in it?

I'm pretty sure the minimum fuel for all the "regular" cars is RON 95 nowadays.

Here In Israel and Europe we have RON 95 wich equivalent to your 91 octane.
There is no lower that 95 here

Yeah, octane is basically a fuel's resistance to detonation. The more resistant a fuel is to detonating, the more air and fuel you can compress in a cylinder before it ignites. Higher octane gasoline typically also has more/better detergents and additives added to it.

>put 87 in the car
>smells of fuel when sitting in traffic
>put 89 in it
>smell goes away

>murricans throwing shit at each other in a 87 vs 91 debate
>i can't even go lower than 95 for my econo shitbox in yurop

you dont even know how good you have it for slaughtering sandniggers for their oil and not having stupid emission laws

bait

At least you Europoors have decent options for public transportation. I literally cannot rely on trains/buses/etc because I commute 35 miles to my job from an "upper-midde-class" suburb. I would rather be fucking sleeping or reading on my way to work, but because of shitty American urban planning 90% of the populace has to drive their own cars.

>At least you Europoors have decent options for public transportation.

>it's now infested with niggers and muslims bashing grannies to death for their wallets with 30€ in it

yeah... our superior public transportation... heh

Get an aftermarket tune and then run whatever gas the tune specifies so you don't feel like you're getting hosed and at least your car will perform better.

DIFFERENT FUCKING OCTANE RATING SYSTEMS THIS HAS BEEN SAID 100+ TIMES

Maybe in the West. Worst thing that can happen in Central Europe is some girl accidentally grinding your dick in a full bus.

>he lives in a shithole
seriously tho, where the fuck are you not able to find even 95 octane gasoline nowadays?

Ethanol gets condensation. The water sits on top of the fule at the gas station. When they get low you get water in your tank. I learnt it the hard way. I was filling my Harley Davidson up with 100% octane not knowing it was ethanol.it rusted out my tank. Rust went through the motor. $4,500AUD to fix it. I never use ethanol now.

87 all the way, so few octane levels doesn't make a fucking difference, this is no more than a marketing strategy

This is why you stick with Shell or other reputable stations. They don't let their tanks run to empty. It's not worth cheaping out on gas to save $3 a tank.

>crying about paying for 91oct

Try running 260GT

How much is the gas price? What gas does it use? 91 octane, 14gal for me is like 42 usd dollars.

8.99/gal for 100oct. Either that or meth or E85 to push 30psi.

PROTIP: don't park your sweet ride in front of a sign that says "community college."

Not filling up with the recommended fuel is like not changing your oil. You are abusing a very expensive machine. An alternative is adding HEET to your fuel tank every fillup.

you have to be honest with yourself to come to the correct answer. how much time are you spending in the engine's powerband at full throttle per tank? because thats when the knock sensor is going to start cutting timing and running richer. if you're on a track that could be 80%, if you're commuting that could be 0%. if you are cruising around town racing people its not a big enough difference to change the expected mileage, but you'll probably notice the difference in power

Often enough that when I romp on it, that's exactly when I want it to perform as intended and without danger.

Otherwise I would have bought an appliance car in order to deprive myself of a little ray of sunshine in my miserable life.

>we wuz educate

>he doesnt drive an appliance car in order to allocate more money for his insane toy
pfffffffttt hhahaha dadposter

The leaner burn of the 87 was causing a knock in your engine, so your ECU retarded the ignition timing to mitigate it.

>USA, the great land of the free
>standard fuel is 87 octane

europe laughs at you cucks

the average 18 year old america knows the difference between RON and AKI and laughs at you, because your parents only own a 1.2L Micra and you never drove until last year, so of course you wouldnt know

>Not having a 55g drum of VP 117 in your shed

Fair call. It was a shit servo chain. I don't go there any more

Is that what retards think the knock sensors do?

Its not a failsafe for ultra retarded operations. It makes the engine work just fine with retarded ignition.

It appears you also work retarded, by the way.

It's a reactive system. It won't pull timing until it detects unexpected detonation. It really is a safety mechanism.

The early USDM STi engines had timing that was too aggressive and it was too aggressive about turning the timing back up to the default when the knock sensor wasn't detecting knock. Consequently, it caused a large amount of concern among the early owners about the engines audibly pinging all the time, and concerned about whether or not this accounted for some of the unexpected early engine failures. In later years, Subaru revised the timing map and timing adjustment so it wasn't always banging against the knock sensor.

A single knock wont grenade the engine, user.

And many ECU's, even stock ones, after flashing let you remap the spark timing.

i run 98 (same as us 93) just because i get better fuel economy, works out cheaper in the end.

Right. I'm just saying if you think of the knock sensor as something you want to be riding the engine again, you're missing the point. It exists as a safety device to pull timing when combustion conditions manage to go outside of the designed expectations

You are correct. But your assumptions are that it makes a big difference that you run knock a few times. It doesn't.

Of course if you NEED the engine to live as much as possible, its a bad idea to have knock, or to run lesser octane, or to let the filters get dirty, or to not run oil changes all the time. But after distributorless computer controlled ignition the knock isn't as much of a scare as it was back before.

I personally only run 93 and up (US octane ratings). This is because I have breather mods and a tune so I’m positive that the car would run like absolute shit if I didn’t.

I usually run 91 octane in this (429 Thunderjet) because I heard that it compensates for the lack of leaded gasoline

That's why I gave the example of the STi where the ECU was always eager to turn the timing back up until it started knocking again because the default maps were unrealistically close to the edge for US conditions.

If you want to chronically run your engine outside of what the default maps are designed to tolerate, then you're fundamentally rolling the dice as to whether the ECU will just learn a long term timing correction rather quickly and keep you from any worrisome amount of knocking, or whether the ECU is going to keep trying to get back to what it thinks ought to be reasonable.

These are the power figures for Hyundai's Lambda II 3.8 V6 GDi.

344 hp @ 6400 (Regular)
292 ft-lbs @ 5100 (Regular)

348 hp @ 6400 (Premium)
295 ft-lbs @ 5100 (Premium)

>4hp/2ft-lbs difference
>inb4 throttle response/butt dyno/etc.

go be poor somewhere else, busrider

Whoops meant to put 3 ft-lbs

These are the power figures for Hyundai's Lambda II 3.8 V6 GDi.

344 hp @ 6400 (Regular)
292 ft-lbs @ 5100 (Regular)

348 hp @ 6400 (Premium)
295 ft-lbs @ 5100 (Premium)

>4hp/3ft-lbs difference
>inb4 throttle response/butt dyno/etc.

nice mad max poster

numbers aren't the point of running different gas in cars you dumb faggot bus rider

Because the engine will knock.
It will knock then the ecu pulls timing.
The ecu will put timing back in because it wants to run as advanced as it can, but it will always knock.

How much damage does that cause? I don't know, but I do know knocking on cast hypereutectic pistons is never good.

I get 93 my baby deserves it

My car calls for 87. I put 91 in it and then crashed into a pole. So i guess it didnt like 91.

Yeahhhh no it isnt you jealous cuck

>mfw engine designed for 78 octane (RON)
>mfw performance decreases at 100 octane
>mfw 95 octane is the worst fuel I can get

>americans dont even have 99

I put 97 in my car and its not even good.

How the fuck your burgerclap engines run on 87, I'll never know

Should you feel nervous or unsure of what fuel octane your vehicle requires, please consult the owners manual.

why would you have 55 grams of it?

They have a diffetent rating than we have.
95 in our rating is about 91 in their rating.

this really depends on the vehicle. 1983 buick GNX? better put 91/93 in it. those computer systems were very simple and did not take into account fuel type, or grade. putting 87 in this motor could grenade it in a very short time.

putting 87 in a 2017 zr1 corvette? no big deal the knock sensors will sense that the engine is knocking due to a lower octane fuel and adjust accordingly.

2000 honda civic type r? kind of iffy, it did have a knock sensor, and it did work pretty well. however it was less sophisticated than a simple "i see knock, im pulling timing till it goes away" device. however it is reliable, it also can easily skip a beat and allow a large window of knocking on your engine before correcting the tune making it a less than elegant setup for this question.

>Car takes 95 RON, which luckily is the lowest octane rating over here anyway
>always fill up at the cheapest gas station and use a decent 7% discount
I'm still doing an LPG conversion if petrol gets any more expensive though, propane is about half the price of petrol.

>Diesel with a black handle

plz don't tell me this is a thing.

Burgerclapistanese here

Yes. Petrol pumps have green handles and diesel ones black.
They also have different size nozzles so at least you can't fit the larger nozzle in the smaller hole.

It'll run on RON95 yes, however it will run more rough.
Actually had a check engine light come on after using RON95 for about a month, before I realised I was supposed to put in 98 rather than 95
The sticker in the gas hatch also says to only put in RON98 fuel.

What the fuck

Murrica' green is diesel

So I put 91 in my Pontiac Vibe (1ZZ FE engine) because fuck ethanol. It has 170k miles. My understanding is that there's more chemical energy in the fuel, so therefore I get better fuel economy.

My question is, should I change the engine tuning to take advantage of the fuel? If so, how do?

I usually see yellow for diesel and various colors but mostly black for gas.

>Murrica' green is diesel

Because farmers.

Actualy your ECU corrects that automaticly...

>Even worse offenders won't post their 91/93 octane prices on their signs,
t. every single fucking gas station in Canada
i was blown away when i went to the states and saw the price of every octane level on the signs, i had never seen that before in my life

That's fucking cool. Thanks.

americans use a fucking retarded system.
their 87 is our 91
their 91 is our 95
their 93 is our 98 i think? or it might be their 95 is our 98. not too sure on that one.

Man, you can't toast no avocado.

You must not understand what each number means. Both RON and MON are both (archaic) compression tests in different scenarios. They don't tell how the engine acts in many environmental conditions, just a couple.

AKI just takes the average of these because it gives a better idea of them as a whole. But you're so obsessed with how america must be inferior, you have to let everyone know on a Chinese cartoon board in spite.

Baiku thread isn't answering me so I'll ask here.

Ran a tank of 98 RON on my VFR and it ran rough and jittery. Fueled up with 95 RON and ran smooth through the rev range again although feels like there is a bit less power.

Is it just the tuning on it? It's a carbed bike so..

Really? In Canada diesel is yellow

lol calm down cunt just having a few friendly bants. don't get pissy just cause I insulted the system you use.

yes its the tuning. read what your manual says and use that.

The octane level indicates how hot the fuel needs to be before it ignites. The higher the number, the more resistant to igniting. Cars that require higher octane are cars that have a high compression ratio. Forced induction increases the cylinder pressure, which causes the teml to rise. Too hot too soon, and the fuel mixture ignites before the spark plug fires, which is detonation. Which is bad.

A knock sensor will tell the car to retard spark timing, but the car has a small range to correct for. Improper octane level will be very harmful for the engine. The spark timing retarding ability is mainly used for the every once in a while issues, not constant issues.

>tldr
Use the fuel the manufacturer tells you to use.

Manual says 86 or higher (equivalent to 95 RON) but apparently higher means shittier.

Those cars are designed to run a higher octane fuel to prevent pre detonation, this is importantly because the timing is advanced. By using a lower octane you are forcing the ecu to retard the timing a considerable amount just to not cause significant damage to the short block.

Granted the ecu can compensate for lower octane fuel, over time repeated fill ups with 87 octane will damage the engine. These cars are designed to continuously run on 91+ octane, not 87.

Tldr stop being a jew

*Important

Auto correct got me

People that don't use the correct fuel for their car are the same people who don't change the oil when their supposed to, rev their car when its cold, etc.... This is basic car maintenance, and is the difference between needing an engine rebuild at 100k and going to 300k on an original engine