So I've just fuelled a whole tank of premium gas after quite a bit of extensive research and all I can say is that I...

>he thinks his shitbox makes noticeably more power on premium when it isn't designed for it

p l a c e b o e f f e c t

Premium burns hotter and gets less mileage, nty.

If your car was designed and tuned to burn low octane, it will NOT make more power on high octane. It is physically impossible. If the car was tuned for low octane fuel, it has no way of detecting that the octane is higher so that it can advance timing and make more power, it can only REDUCE timing advance if it detects detonation.

The only possible way switching to higher octane fuel made a difference in power in your low-octane optimized car is if the low octane fuel you were buying is old stale shit or contaminated.

My car has a naturaly asprated engine with 1:10,5 compression ratio, every fuel available in germany is already too good for it.
Jow exactly should it benefit from 100 or even 102 RON fuel?
It gets 95 RON wich is already more than it needs.

My motorcycle runs worse (5% less top speed) on 100 RON V-power than on 95 RON, the only difference betweenboth fuels is in the additives.
The 100 octane fuel is so knocking resistant, it burns slower than 95 RON fuel.
Wich means that my 8000rpm bike engine looses power due to slower combustion.

MiTo
And as far as I can google this engine really hates ethanol additives.

It's designed for 95RON, not exactly shitbox too.

Indeed it does. Also due to the fact that the engine might be calibrated for normal gas it might pump inside much more than necessary thus making the mileage even worse...

But this is only valid if we talk about "gas with syntetic additives" which is what I fuelled. In Garmany and in other countries you will find "Gas + 5/10% ethanol" sold as "regular" gas. And since the ethanol burns differently it might fuckup the internal sensors so the engine just doesn't run properly. No?

The only reason to get that 100RON fuel for your car is a increased compression ratio or a huge manifold pressure.
Pretty much no stock engine can actualy use that knocking resistance,

>MiTo
>not exactly shitbox
Just because it's italian doesn't mean it isn't a shitbox. It's an economy car, which means by default a defacto shitbox. Not all shitboxes are economy cars, but all economy cars are shitboxes.

>"Gas + 5/10% ethanol"
That counts as "contamination"

>And since the ethanol burns differently it might fuckup the internal sensors so the engine just doesn't run properly. No?

Not really, if anything extra ethanol raises the octane rating a bit. E10 is really only an issue with older carbureted vehicles, where even 10% is enough to ruin fuel lines and carb seals over time, and the hygroscopic nature of ethanol pulls water from the atmosphere over time and promotes corrosion in the carb(s).

The whole "Multiair" stuff disqualifies it from the shitbox area IMHO.

That contamination can still sometimes give you a "check engine" light.

But ethanol burns differently, every single car needs a ECU update once you are above lets say 33% ethanol content. It it just raised octane rating we would all be happily running 100% ethanol trough our cars, flexfuel wouldn't exist and I wouldn't need new injectors in order to switch to it.

up the compression to compromise, you'll get more power and better milage

>this whole thread

except

If your car is built for standard, you run standard. Some engines simply run better and longer on standard octane.

>The whole "Multiair" stuff disqualifies it from the shitbox area IMHO.
No.

Fucking italaboos think their shit doesn't stink

t. bus rider

Wow that's a mature and reasoned argument. Congratulations.

I think that it's on the same level as "Fucking italaboos".

>fiat fanboys think a modern engine means their shitbox is no longer a shitbox

Dude you're driving a tiny economy car which is slow, poorly equipped and poorly styled. Yeah it has a modern engine in it, but the modern engine didn't make it well equipped or foast. It's still a shitbox.

>I know, I'll win the argument by stooping below the other person
kek
You deserved being called an italiboo, because you're a fanboy.

dude you're fucking R E T A R D E D

You literally have NO CLUE what the purpose of high octane fuel is

>""""""""""premium""""""""""
LOL you got jewed SO FUCKING HARD

It's for engines that are running at a higher compression rate than usual, so you need fuel that doesn't ignite easily - high octane fuel, so your engine doesn't detonate.

YOU ARE A FUCKING FAGGOT HAHAHA

>I definitely feel the difference
HAHAHAHAHAHAHAHAHAHAHA

unless your car is specifically designed/tuned to run on premium it'll be the same as running cheaper fuel

read the manual, use the minimum grade it suggests, or whatever you're tuned to -- higher quality fuel has increased knock resistance which the tuned cars to advance the timing and make more power.

econoboxes are designed to take shitty fuel and can't take advantage of the higher knock resistant qualities of the premium fuel

Stay in school, kids

There is objectively, proven zero difference if your car was not made for higher octane. Did you advance the fuck out of your timing? Then no you don't gain anything from it.

Fucking shill, get off our board. The ONLY difference in premium fuel is that it ignites SLOWER. That's right, it doesn't combust as easily as lower grade fuel. This is a good thing in cars that make a lot of boost, as the fuel will resist premature detonation a lot better. In all other cars, it's a bad thing. You want a faster, more violent detonation, not a slower one.

Also faggot, you live in Europe, the lowest grade of fuel you can get is equivalent to our second highest (highest in some places). Fucking get out you fagfucking independent local gas station owner's union shill.

Also, every really powerful car on the market today knows what it's being fed. If it senses low grade fuel, it'll adjust timing and boost accordingly. You're getting jewed if you buy anything higher than the lowest grade fuel unless you own a car where the manual recommends premium AND you actually drive it hard.

Faggot.

Octane is *resistance* to combustion.

Unless your car was tuned for it you may even be losing a minuscule amount of power by using a higher-than-necessary octane.

haynes manual says I don't need it

I can tell shitty 91 vs good 91 instantly

>If it senses low grade fuel, it'll adjust timing and boost accordingly.
This is wrong. Even hypercars can't detect fuel octane rating, they can sense ethanol content, but adjusting for octane is 100% due to knock detection. You don't want to put low octane shitgas in your high performance car which tells you to use premium because if for some reason you subject it to heavy load and go WOT, such as passing on a hill in a headwind, it could detonate enough to damage the engine before the timing retard has a chance to pull enough.

Jesus fuckign christ on a bike are you faggots really suggesting that it doesn't matter at all what fuel you put in your car? Really? And I thought that this is the least autismo board on Veeky Forums. Fuck me for wanting a normal discussion instead of the usual "Should I X or Y/anime/this car I can never afford sucks" shit. And fuck me for trying something before posting instead of the usual Veeky Forums IjusthadanideawhilejerkingtomyfaggymiatasoIwillpostit drill.

>you live in Europe, the lowest grade of fuel you can get is equivalent to our second highest (highest in some places).
Daily reminder that burgers and europoors measure octane differently.

>are you faggots really suggesting that it doesn't matter at all what fuel you put in your car?
Yes because it doesn't. There isn't a "quality chart" for gasoline. It's either gasoline or it's not. It's either 89 octane, 91 octane, etc, etc or it's fucking not. If you car says "put 89 octane in me" and it has not had a specific tune that says otherwise, YOU PUT FUCKING 89 OCTANE GAS IN IT. Putting anything else will either be a waste of money at best or actually make the engine perform worse. Regular, mid-grade and premium are just marketing terms. They mean jack shit other than "This is low octane, this is high octane." Some, SOME companies will use only gasoline in their premium pumps and be ethanol free. That is the only and singular benefit to using premium over regular in a normal car and it's often not worth the extra cost.

/thread.

They also get different grades of fuel. You'll be hard pressed to find anything lower than 95 RON in Europe, which is 91 AKI. Their "premium" is 98 RON, our 93.

>not being able to get 87
Stay jewed

Actually, knock prediction exists. Different from prevention.

>Actually, knock prediction exists. Different from prevention.
Your car CANNOT detect the octane rating of the gasoline you put in it. It can ONLY pull timing advance to compensate for knock it hears with the knock sensor, and keep said advance reduced for whatever length of time it is programmed to before trying to advance it again and see if there is still a knock condition.

Hello COfag.

I got a 2015 Mustang GT
Should I be running Regular or Premium?
I run my gas from Costco so price doesn't really matter. 5 buck difference at best

you should read the manual. in CO 'regular' is 85; my car says to run at least 87 (fiesta ST)

Not in the Volt. It's the other way around.

Open the owner's manual.
Read what octane it recommends using.
Use that octane.

You won't get better performance by running your car on higher octane gas than what it was designed for.
You will get shit performance and worse fuel mileage by running your car on lower octane gas than it was designed for.
The end.

What does the manual say you fucking twat?

My mileage went up considerably after switching to premium in my turbo shitbox

Your car gets nothing out of premium if it isn't tuned for it

It'll smell nice though

My E36 M3 got about 2-3 MPG less on average with non premium gas, ran like poop too

Then again it was designed to run on premium.

If your car was designed to run on premium, use premium. If it was designed to use regular, use regular.

If you are doing anything other than this you're both poor and retarded.

Automotive engineers know more than you do.

>1.6L
>t. Priusfag

Or your car can take advantage with extra timing = more power

Retard here. What exactly is the number measuring? % volume of octane? Molar concentration? I know some countries use the RON system.

en.wikipedia.org/wiki/Octane_rating
Dunno how the US test works but in here we use RON, so our "regular" is 95RON and premium is actually sometimes just 95RON without ethanol and with better additives or more recently 98RON ethanol-free gas with high quality additives. You can also buy 91RON in rural areas sometimes but it's really rare. Also these number are actually spot on (like 0.3RON difference is tolerated). I have yet to see 100RON gas in here, AFAIK even the amateur aeroclubs use 95/98RON in their planes.

Now ethanol gives higher octane rating but absorbs moisture from air so it's not really good when you use your car like once or twice a month or if you have a different car for winter and a different car for summer. Also the premium gas has like 10 times less sulphur in it so the engine life should go up a lot (especially stuff like the injectors etc.).

But it's common to just tank 95/91 even to new vehicles that require 98 when you plan to sell it after 2-3 years. That will fuck up the next owner tho. People are fucking thieving niggers.

IMHO just read what's in the manual and then look at the seals in the gas station and find premium gas with nice price (and from well-known seller hence the "check local forums) that has equivalent rating to the manual one and fuel that.

The gap between cylinder head and piston is 0,6mm, how should I increase the compresssion?
>inb4 piston
There are only normal compression ones available.

>AFAIK even the amateur aeroclubs use 95/98RON in their planes.
Not every plane can handle unleaded fuel, most older planes require avgas100LL, wich has at least 100 MON.

Tell me in your own words the difference between regular and premium

A shitbox with turbo that needs high octane fuel for optimal timing will lose power to prevent knock if it runs on lower octane...
Is this really Veeky Forums or is it /mlp/?

see
Sure but around here people fly as a hobby a lot and like 80% of their aircrafts are fairly new. And these people usually just buy fuel from the same gas stations as the fuel for their cars. The rest (old/big turboprop engines) have their own fuel delivery.

I like ponys tho.

Skim the head

in NZ normal fuel is 91RON
Premium is 95 and some stations have 98 instead if 95

Unless your black 95 Is the standard
91 is for lawn mowers

>inb4 ban
There is litteraly not a single pony in this video.

There is nothing there explaining why it would give you more power or performance tho

>oil leaking into cylinder 1
>have to use ron98 with the engine's ron plug set at 95 to stop it from pinking like a madman

I believe that it's the better additives, lower sulphur levels and lack of ethanol (which my engine hates with a passion) that causes the difference. Also I don't know if there is a power increase, but I do know that the throttle response is much better around 2-3K RMP...

Most states in the mountain west will have 85 octane as the regular or standard grade, with 87 and maybe 91 octane at a pump along with diesel. If you car's manual says to use a higher octane rating than standard, then use the higher one. For turbocharged vehicles you need a higher octane no matter the altitude. I always fill up with 85, but my tank is almost empty and tomorrow I'm going to try out 87 to see if there's a difference. 7200 feet above sea level by the way, so since my car seems to run just fine with 85, 87 should theoretically make no difference. I'll report back tomorrow.

While we're on the subject, is it true that rotary engines will run the best only on the lowest grade fuel?

lowest grade now, lowest octane yes kind of
an old carb'd rotary hates high octane and would rather suck down the lowest octane you can get
but a turbo rotary will go KABOOM if you put 87aki or whatever in it

Yes, as every engine does.
Run the lowes octane rating your engine is build for.

How fucking retarded are you?
ECU hears detonation so it pulls timing.
IT
CANNOT
DETECT
OCTANE
RATING

And detonation occurs when you run fuel with a too low octane rating for your engine, so the ECU can detect a low octane rating, but can not quantify it or detect a high octane rating.

No, fucking moron, detonation could occur for other reasons, the ECU CANNOT DETECT OCTANE RATING OF YOUR FUEL ALL IT CAN DO IS RESPOND TO DETONATION

Octane rating is a rating about knonking, not more, not less.
If you put a low octane fuel in a high compression or turbo engine, you will get detonation if your ECU won´t preignite your charge befor it ignites due to compression or detonates.

There are many reasons detonation can happen, fucking moron. Wrong fuel is ONE.
>combustion chamber deposits
>EGR malfunction
>wrong base timing
>spark plug range too hot
>mixture lean
>exhaust valve overheated
Git gud

As I wrote before the ECU can only tell if the fuel has a too low octane rating for the engine and can not quantify the octane rating.
It can do so due to the knocking sensor wich detects when the combustion is a detonation.

I drive premium because I have to, not because I want to.

You're retarded if you put above 87 in your tank unless you're using forced induction.

>tfw your engine requires premium

>The Year of Our Lord, 2017
>Not using forced induction

This desu

Dunno but in my '13 Focus when I put cheap ass gas I have to press the throttle a bit more when starting or else the engine starts knocking, with premium or midgrade that doesn't happen.

>his engine doesn't run happily on cetane 51