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When I run 93 octane fuel my check engine light comes on after a couple tanks, dealer tells me too much alcohol. In the manual it says 91 octane and below.

Is there a way to optimize it to run on higher octane fuel? I'm assuming a tuner like Racechip, but I wanted to see what yall think about it.
 

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What OBDII code is set when your check engine light comes on?

I've run two tanks of 93 octane and did not have a CEL - I went back to 89 octane because I didn't feel any seat-of-the-pants difference.
 

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When I run 93 octane fuel my check engine light comes on after a couple tanks, dealer tells me too much alcohol. In the manual it says 91 octane and below.

Is there a way to optimize it to run on higher octane fuel? I'm assuming a tuner like Racechip, but I wanted to see what yall think about it.
Go to a different gas station? Racechip not a real tuner. You should never get a engine light running 93 on this car.
 

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Go to a different gas station? Racechip not a real tuner. You should never get a engine light running 93 on this car.
You might if the fuel is achieving 93 octane by running 25% ethanol or something, but that would be unusual, because I think they'd have to label the pump for that. Pretty much every car sold in North America can run E10 (10% ethanol) fuel, but beyond that concentration, ethanol would screw with the O2 sensor readings (and potentially damage seals in the fuel system), so it's a pretty big deal if the fuel has more than 10% ethanol without it being labelled on the pump.

Also, I'm pretty sure my Canadian 2021 Forte manual (there is no separate manual for the GT) states 87 octane or better fuel. It doesn't provide a maximum octane rating, and I have never seen that in any car ever. It does specify the maximum amount of ethanol allowed and that fuels containing methanol should never be used. There's also possibly no use in running 93 octane fuel. Has anybody been able to determine if the engine with a stock tune actually provides better performance above 87 octane? Most turbo engine do, but they always tell you in some way. Something like "87 octane acceptable, 91+ octane recommended" (like my Dodge Dart 1.4T did) or they actually provide the reduced horsepower rating with 87 octane (like the Ford Focus ST did). Kia just says "87 octane or better" on an engine they are advertising as 201hp, so they could be in hot water if it can't make 201hp on 87 octane fuel.
 

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You might if the fuel is achieving 93 octane by running 25% ethanol or something, but that would be unusual, because I think they'd have to label the pump for that. Pretty much every car sold in North America can run E10 (10% ethanol) fuel, but beyond that concentration, ethanol would screw with the O2 sensor readings (and potentially damage seals in the fuel system), so it's a pretty big deal if the fuel has more than 10% ethanol without it being labelled on the pump.

Also, I'm pretty sure my Canadian 2021 Forte manual (there is no separate manual for the GT) states 87 octane or better fuel. It doesn't provide a maximum octane rating, and I have never seen that in any car ever. It does specify the maximum amount of ethanol allowed and that fuels containing methanol should never be used. There's also possibly no use in running 93 octane fuel. Has anybody been able to determine if the engine with a stock tune actually provides better performance above 87 octane? Most turbo engine do, but they always tell you in some way. Something like "87 octane acceptable, 91+ octane recommended" (like my Dodge Dart 1.4T did) or they actually provide the reduced horsepower rating with 87 octane (like the Ford Focus ST did). Kia just says "87 octane or better" on an engine they are advertising as 201hp, so they could be in hot water if it can't make 201hp on 87 octane fuel.
I get what ya saying 🙂. At the moment Im running E40 and Water Meth soon not stock tune.
 

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Mine is stock, and I've run 93 almost exclusively since I bought it 4K miles ago. It's not the gas.
 
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I have a 2021 Forte 6MT with the naturally aspirated 2.0. Reading the specs on the engine, it has 12.5:1 compression ratio. Typically, once you hit 11:1 you require 91 octane if your engine does not have variable timing. This in and of itself suggests potential for effective utilization of higher octanes. In another thread I noted an odd acceleration curve, and after using 91, I can say that they has definitely smoothed out, although I can't say it has had actual performance gains. My next step is to boost the octane even further with additives, and then abruptly go back to 87 to see how much of a difference I feel.

Theoretically, if the engine has higher compression and variable timing and fueling, it should extract more kinetic energy with higher octane.
 

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I have a 2021 Forte 6MT with the naturally aspirated 2.0. Reading the specs on the engine, it has 12.5:1 compression ratio. Typically, once you hit 11:1 you require 91 octane if your engine does not have variable timing.
Sorry but that is not correct. Static compression does not take into account valve duration and timing. You will not see any gains by using higher than 87 on your stock n/a motor.
 

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Sorry but that is not correct. Static compression does not take into account valve duration and timing. You will not see any gains by using higher than 87 on your stock n/a motor.
Sorry, but I don't think you're correct. But thanks for chiming in.
 

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I have a 2021 Forte 6MT with the naturally aspirated 2.0. Reading the specs on the engine, it has 12.5:1 compression ratio. Typically, once you hit 11:1 you require 91 octane if your engine does not have variable timing. This in and of itself suggests potential for effective utilization of higher octanes. In another thread I noted an odd acceleration curve, and after using 91, I can say that they has definitely smoothed out, although I can't say it has had actual performance gains. My next step is to boost the octane even further with additives, and then abruptly go back to 87 to see how much of a difference I feel.

Theoretically, if the engine has higher compression and variable timing and fueling, it should extract more kinetic energy with higher octane.
This logic applies to the Otto cycle, but the 2.0 NU engine in the 2021 Forte uses an Atkinson cycle, which reduces the effective compression ratio (by keeping the intake valve open for part of the compression stroke) while still having an expansion ratio (during the power stroke) of 12.5:1. The net result is more complete and efficient burn, but with a reduced power output.

The measured "compression ratio" of an engine (in this case 12.5:1) is a static figure that merely shows the difference of volume in the combustion chamber from bottom dead-centre (BDC) and top dead-centre (TDC). It doesn't necessarily mean that the piston will compress the air in the chamber by a factor of 12.5, and in the case of an Atkinson cycle, it means it absolutely doesn't. I don't know what the actual effective compression ratio is of the 2.0 NU engine, but the goal with the Atkinson cycle is that at BDC of the power stroke, the pressure in the combustion chamber is equal to atmospheric pressure. If this is achieved, it means that all of the available energy has been extracted from the combustion process. The downside is reduced energy density. The real world effect is improved fuel economy and less waste heat, but at the expense of potentially more power.

You won't be able to extract more power by increasing the octane of the fuel, because the engine isn't de-tuning itself to accommodate 87 octane, it's actually tuned for optimal performance using 87 octane fuel. You would need to re-tune the engine to provide a higher effective compression ratio during the compression stroke (which may potentially also require a different intake cam profile) to take advantage of higher octane fuel's resistance to detonation during compression.

EDIT: Not to mention, this whole conversation is totally off-topic for this thread, since the OP is having an issue the with the 1.6 turbo, not the 2.0 NU.
 

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The car makes more power with better fuel even on the stock tune (GT). Enough to feel? No, Enough to make a difference? Sure if you fix all the other issues (the launch, shifting, DA, track conditions).

My car has made 195 whp uncorrected Map 0 (pass-through) on 91 octane. It's made 201 whp with 20% Ethanol.

I am really tired of this debate especially coming from the same guy who's car is stock, s-slow and is a typical Hyundai/Kia owner IE they don't really know it's strictly guessing.
 

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When I run 93 octane fuel my check engine light comes on after a couple tanks, dealer tells me too much alcohol. In the manual it says 91 octane and below.

Is there a way to optimize it to run on higher octane fuel? I'm assuming a tuner like Racechip, but I wanted to see what yall think about it.
Take it to the dealer, you shouldn't get a code at all.

Racechip? No
 

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I am really tired of this debate especially coming from the same guy who's car is stock, s-slow and is a typical Hyundai/Kia owner IE they don't really know it's strictly guessing.
Higher octane in on a stock N/A forte is doing nothing draining your wallet.You are getting zero performance increase. Period.
 

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Sorry, but I don't think you're correct. But thanks for chiming in.
Sorry to tell you but you are incorrect. There are thousands of engines running perfectly fine on 87 with higher than 11:1 compression.
Hyundai/Kia engineers have designed the N/A Forte to run on 87 octane fuel.
 

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And I’m really tired of asshole idiots like you that think they know everything. If you were so smart you would have bought a real performance car in the first place, not try to make one out of a basic transportation economy car.

Higher octane in on a stock N/A forte is doing nothing draining your wallet.You are getting zero performance increase. Period.
I was talking in the context of the GT and the OP car is a GT, reading is fundamental. You like last time around fuel quality was talked about jumped in with both feet because that's your personal gripe, hobby horse, soap box, etc.

It's really the only thing you know about and it shows since you have nothing to say about anything else surrounding the 1.6L GDI-T.

I don't disagree that in the case of the 2.0L engine that better fuel likely means little difference especially if you don't log it to find out.

My car has 50 dyno pulls on it, every time it's made the same numbers stock tune/Map 0 with the JB4 inline. That cannot be refuted.
 

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Do your research:
 

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Do your research:
The Forum Warrior is back in a thread he doesn't belong in again, doesn't even own the car, and does more internet search copy pasting. Most ppl have alrdy told you to leave threads and mods deleted ur nonsense and posts. Why bother patrolling here. Go find a different hobby. Another derailed topic for u to weasel ur way in.
This person who made this thread just needs to go the dealership and get the car looked at for a check engine light on when using pumped gas or go to a different station and see if its that's the issue. If mixing E blend to achieve a higher lvl he might want refigure his mix numbers. Ill be getting a mod in here to keep from back and forth nonsense that i see is happening.
 

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The Forum Warrior is back in a thread he doesn't belong in again, doesn't even own the car, and does more internet search copy pasting. Most ppl have alrdy told you to leave threads and mods deleted ur nonsense and posts. Why bother patrolling here. Go find a different hobby. Another derailed topic for u to weasel ur way in.
I was replying to two posts about the 2.0L engine, not your 1.6L turbo.
You’re a real tough guy driving an economy car thinking it’s a performance car. Let me know when you buy a real performance vehicle.
 
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