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The manual recommends 87 octane but it also says research 91? Anyone know what that means? Anyone experience using other grades besides 87 without any problems?
 

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I think I remember reading on the Genesis forum some time ago it was said that the Genesis engine's potential horsepower maxed out with 91 octane rating. I believe (in the Genesis at least) that 87 could be run if that specific individual engine would behave with it, but a lower horse power would result. Engine ignition timing settings, compression ratios, etc. would be a big part of whether that would be fact.

I guess that would be a general statement for most engines, but I wouldn't bet on it for the Cadenza. Sometimes HP ratings are committed to on manufacturer statements under strange DOT or place of origin regulations and guidelines.

Any opinions out there? I guess this may not be the kind of answer murrwin is after.
 

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Discussion Starter #4
I think I remember reading on the Genesis forum some time ago it was said that the Genesis engine's potential horsepower maxed out with 91 octane rating. I believe (in the Genesis at least) that 87 could be run if that specific individual engine would behave with it, but a lower horse power would result. Engine ignition timing settings, compression ratios, etc. would be a big part of whether that would be fact.

I guess that would be a general statement for most engines, but I wouldn't bet on it for the Cadenza. Sometimes HP ratings are committed to on manufacturer statements under strange DOT or place of origin regulations and guidelines.

Any opinions out there? I guess this may not be the kind of answer murrwin is after.
Thanks for your response, it did help a lot! When my tank gets low, i will put a gallon of a higher octane to see how it runs.
 

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Like to know your process when modifying......

3.3 is ok with 87, the 3.8 likes 93
Thanks!

Can you keep me/us updated with your modifications? especially with the Headlights and Fog Lights. I bought new DSC1 HID Lights to change them from 4300K to 6000K. I want to do it myself but scared to because I don't want to break the clip. let us know how it goes and what to do if you don't mind. Hopefully everything will go okay if you are changing them yourself.
 

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...i will put a gallon of a higher octane to see how it runs.
Every three or four tanks I will fill up with the good stuff. I guess it's psychological but I feel that it helps to clean the crap out of the chambers and maybe even the injectors. Probably not so much, but it makes me feel that I did something nice for the car. The ECU no doubt compensates the engine performance to handle the added octane.

I also dump in a bottle of fuel additive once in a while...also probably more good for the psyche than the car.

John
 

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Thanks!

Can you keep me/us updated with your modifications? especially with the Headlights and Fog Lights. I bought new DSC1 HID Lights to change them from 4300K to 6000K. I want to do it myself but scared to because I don't want to break the clip. let us know how it goes and what to do if you don't mind. Hopefully everything will go okay if you are changing them yourself.
i'll prolly leave the headlights alone... i too am scared to screw something up, esp because of the articulating headlights. once i find some LED Fog replacements, i'll tackle that and hopefully mod them for DRL along with the existing LED light bar in the headlight fixture.
 

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Every three or four tanks I will fill up with the good stuff.

I also dump in a bottle of fuel additive once in a while...also probably more good for the psyche than the car.

John
John, it's not good to experiment with gas which is not recommended as it could damage your engine more than help....

However you are right about additives - it is recommended by KIA for your regular service...however they recommend to use only one they have...of course :)

Andrei
 

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...I'm a bit of a renegade...I'm thinking that if Kia used a properly written ECU logic/code that it would compensate for lower octane to an extent (knock sensor) and retard timing if the effects of higher octane were adverse (hot spots?). Also, I'm thinking that if their coding is regulated like most SAE specs, they design in some "fudge factoring" to account for rating errors of the fuel itself. The "fudging" is usually way off on the safe side. You're probably correct that the higher "proof" gas would not really help much. I know over the years there have been two schools of thought on running higher octane fuel. The basis in fact on the arguments is similar to "what oil is better?" or "is Ford better than Chevy?", i.e., we may never know the truth for sure.

Andrei, I just wanted to give you some [email protected] for a change. I'm always too nice to you. lol

John
 

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The manual recommends 87 octane but it also says research 91? Anyone know what that means? Anyone experience using other grades besides 87 without any problems?
You can read about octane rating on wiki:
Octane rating - Wikipedia, the free encyclopedia

basically in US pump 87 = 91 (RON) - Research Octane Number (RON)

"regular" gasoline in Australia, New Zealand, Canada and the US:
Research Octane Number (RON) = 91–92
Motor Octane Number (MON) = 82–83
pump ((RON+MON)/2) = 87

I'm concerned about premium gasoline because it contains 10% ethanol...according to WIKI:
"Premium" or "Super unleaded" gasoline in US (10% ethanol blend) 97 87-88 92-93

According to manual - if fuel contains more than 10% of ethanol it could damage your car and will void warranty...
However it also said that engine could use 87 or higher...

So we need clarification from KIA engineers what is safe to use except 87 :)

Andrei
 

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However it also said that engine could use 87 or higher...

So we need clarification from KIA engineers what is safe to use except 87
BINGO! I agree with that, Andrei.

Yes, the minimum recommended fuel is based on AKI (Anti-Knock Index) or the minimun grade that the vehicle will accept before pre-ignition symtoms. On the other hand, there is research evidence that running an octane higher than required can lead to exhaust valve damage over time due to the slightly slower burn characteristics of the higher octane fuel. In Asia, and I think in Europe they use a concept called RON or Research Octane wherein they base all of the engine's performance characteristics on, say 91 octane, and then recommend the AKI grade fuel. So there is some confusion, and as you say Kia would be the final word as to what they recommend for the Cadenza.

Now, let's go and have a fun day!

John
 

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Discussion Starter #13
i'll prolly leave the headlights alone... i too am scared to screw something up, esp because of the articulating headlights. once i find some LED Fog replacements, i'll tackle that and hopefully mod them for DRL along with the existing LED light bar in the headlight fixture.
Oh okay, yeah I'm on the same boat. I already bought 6000K HID replacement bulbs. The car takes DS1 Bulbs, they are really easy to replace usually but in this case the car has one chrome bracket around the bulb which is making me scared to try and remove. Other wise it is a simple swap. The bulbs only cost $100. The fog lights take H8 which are standard and should be an easy swap hopefully, i'm going to get the 120 SMP LED Bulbs for the fog lights. After that I will get 2357 Front Turn Signal LED Switchbacks. The whole front of the car will be at 6000K!
 

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Oh okay, yeah I'm on the same boat. I already bought 6000K HID replacement bulbs. The car takes DS1 Bulbs, they are really easy to replace usually but in this case the car has one chrome bracket around the bulb which is making me scared to try and remove. Other wise it is a simple swap. The bulbs only cost $100. The fog lights take H8 which are standard and should be an easy swap hopefully, i'm going to get the 120 SMP LED Bulbs for the fog lights. After that I will get 2357 Front Turn Signal LED Switchbacks. The whole front of the car will be at 6000K!
i CANT WAIT TO SEE THAT!
 

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Hi Everyone, weird story, today I filled up my four week old Cadenza and when I left the gas station the fuel gauge indicted EMPTY and my navigation system prompt me to the next Gas station. I called 24/7 roadside assistance since I'm worried the electronic may shut down the engine (if this would ever be possible). Not much help, the info was to leave the car (thanks god, at home). Anyone out there with the same issue?
 

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Why not just put 87 in?

I don't think clarification is needed past the manual recommending you use 87 octane.

If you bought this car for performance you were shopping in the wrong vehicle category.
 
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