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Discussion Starter · #1 ·
Hello all,
I am running a KTuner V2 in my 19 accord 1.5T with CVT trans and I know Ktuner recommends 91 octane or above. Does any one have any experience with running 87, 89 or 93 and which is best and why?

It seems on start up and shut down I see 1-2 knock count go up, but with all three grades of fuel that hasn't changed. I would expect I should be running 93 if I was going to the track for more power, but for normal commute to work, would running 87 really be that big of a deal? Doesn't ECU continuously correct for fuel anyway with O2 sensor and knock sensor by pulling timing?

Thanks
 

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Don't have any experience to answer your question but have a question for you. Why put an aftermarket performance tuner w/a performance tune on/in your car and not put the recommended fuel in it? There is the saying... "If you want to play, you have to pay"... feed that beast and enjoy it. 馃榿
 

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Discussion Starter · #3 ·
I suppose I have already fallen into the trap of modding my car... I dont mind paying more to have the proper fuel in it but im just being conservative as it only has 11k miles and I dont want to destroy the CVT before 15k miles lol

After conteplating, I just called Ktuner, and here is the answer for anyone. For computer controlled cars suchs as mine. The ECU is able to adapt to the common fuel grades (87, 89, 93 for me). It is based on elevation (Oxygen content of air), and fuel. Running 87 does no create any inherent risks from their opinion. I am just not optimizing my engine as the tuner was mapped on a 91 octane fuel and was recommended to run 93 as its is even better optimized than what they run at. So in conclusion running 87 is perfectly fine for my car it is after all what Honda recommneds you run for the stock car anway. So if you want to be cheap it shouldnt bite you... its just not a full optimization of your capability. :)
 

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I'm not going to get too much into this considering there are practically a million articles and other discussions about this. The ECUs nowadays are very sophisticated and will pull timing, boost, ect if you use a lower octane fuel. You will loose power, but it will protect your engine from exploding. Furthermore the lesser grades have less detergents to clean the engine, which can be useful on direct injection engines.
 

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...

After conteplating, I just called Ktuner, and here is the answer for anyone. For computer controlled cars suchs as mine. The ECU is able to adapt to the common fuel grades (87, 89, 93 for me). It is based on elevation (Oxygen content of air), and fuel. Running 87 does no create any inherent risks from their opinion. I am just not optimizing my engine as the tuner was mapped on a 91 octane fuel and was recommended to run 93 as its is even better optimized than what they run at. So in conclusion running 87 is perfectly fine for my car it is after all what Honda recommneds you run for the stock car anway. So if you want to be cheap it shouldnt bite you... its just not a full optimization of your capability. :)
Exactly... no risk, but you upgraded for performance... get the full benefit of your choice. (y)
 

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Discussion Starter · #7 ·
Per his quote, lesser grades have lesser detergents. More detergents is better- clearing up carbon build up or deposits on pistons, valves etc and helping you gain efficiency. The problem is no companies release their secret formulas for whats actually in them for premium fuel. Most places go on a "Top Tier" standard based off research done by AAA. Post below for more info if you believe nytimes that is. As well a link to top tier brands in the US.


 

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Per his quote, lesser grades have lesser detergents. More detergents is better- clearing up carbon build up or deposits on pistons, valves etc and helping you gain efficiency. The problem is no companies release their secret formulas for whats actually in them for premium fuel. Most places go on a "Top Tier" standard based off research done by AAA. Post below for more info if you believe nytimes that is. As well a link to top tier brands in the US.


Per his quote..
Furthermore the lesser grades have less detergents to clean the engine, which can be useful on direct injection engines.
Is what is confusing me as what you stated regarding the "more detergents" being better (as what I would've thought) is contrary to his statement. Maybe I'm confusing "useful" with "better". :unsure:
 

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Sorry I can see how that was stated could be confusing. Lower grade of octane has less detergents and less cleaning power. Having more detergents can be more useful/beneficial not necessarily better per se. So lower octane fuel has less of the useful detergents and additives than a higher octane fuel which is why the higher octane fuel can be more beneficial. All fuel has to meet certain federal standards octane, renewable, ect. But when you get an actual MSDS sheet for the business year from an oil company, it's makeup can vary vastly from batch to batch because many chemicals listed have a range of varying percentages(and I'm not just talking about ethanol during summer and winter months). For example toluene used to have a range of 1-4% in Shell fuels on one given year. Now I'm not putting atkinson and other engines in this because I have read that with an Atkinson a lower octane/faster burning fuel can be more beneficial to them but that is a different topic. I was always taught by people in the car industry this: "For the extra couple of hundred you may spend a year on a better octane, you will save in the long run on maintenance issues from a cleaner better running engine." Again all relative but you get the idea.
Edit: in this case we are talking about a tuned turbo engine which can have some nice gains just going from 91 to 93 octane. But besides the gains a turbo car is going to run better with higher octane imo, especially after being tuned and having the stock cooling system.
 

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Sorry I can see how that was stated could be confusing. Lower grade of octane has less detergents and less cleaning power. Having more detergents can be more useful/beneficial not necessarily better per se. So lower octane fuel has less of the useful detergents and additives than a higher octane fuel which is why the higher octane fuel can be more beneficial. All fuel has to meet certain federal standards octane, renewable, ect. But when you get an actual MSDS sheet for the business year from an oil company, it's makeup can vary vastly from batch to batch because many chemicals listed have a range of varying percentages(and I'm not just talking about ethanol during summer and winter months). For example toluene used to have a range of 1-4% in Shell fuels on one given year. Now I'm not putting atkinson and other engines in this because I have read that with an Atkinson a lower octane/faster burning fuel can be more beneficial to them but that is a different topic. I was always taught by people in the car industry this: "For the extra couple of hundred you may spend a year on a better octane, you will save in the long run on maintenance issues from a cleaner better running engine." Again all relative but you get the idea.
Edit: in this case we are talking about a tuned turbo engine which can have some nice gains just going from 91 to 93 octane. But besides the gains a turbo car is going to run better with higher octane imo, especially after being tuned and having the stock cooling system.
Thanks for clearing that up for me.
 

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Dexos found out, that too much calcium in the engine oil was the culprit for pre ignition. it builds on the top edges of the pistons. And sets off the piston damaging pre ignition. thats, why we have a SN Plus rating now. and a Dexos 2
 
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