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The engine makes 180hp if you use premium fuel. If you use 87, it will be 174hp. It can use both, as Honda gives you that option. What is the engine really tuned to use? Nevermind the power, what octane is the engine tuned to use?
All premium fuel engines can run on lower octane, and be perfectly fine (let's not debate this). But it's OEM tuned one way, correct? It can adjust different kinds of fuel, etc, but there is still only "one tuned", no?
Some would feel that's sort of the same thing. And I hope you get the just of the question.
Tuned for Premium fuel... the reduced power comes from ignition timing retard detected by knock generated by the lower octane fuel. Less ignition timing makes less HP... and even on it's best moment, the engine will produce LESS than 174 HP. I have seen a reduction in power of greater than 20 wheel HP from the Knock sensors intrusion. Knock control is very protective of the engine.
So, knowing that basically what is happening while you operate the engine on lower than the recommended octane fuel is the engine knocks, ignition timing is heavily retarded from the tune, and then is slowly returned to the tune, until the engine knocks again, and the knock control pulls timing heavily again... keeping the engine in a constant state of reduced power and exposing it to long term extended engine knock. In my mind, this is not worth the savings in fuel cost unless you drive an insane amount of miles on an annual basis. The savings here in the US would be about $6 per tank. For me, that would be about $12 per month... not worth it to me.
All premium fuel engines can run on lower octane, and be perfectly fine (let's not debate this).
No debate, but...
The ECU will continue to try to use the high octane map and pull timing when knock is present. I don't think the ring lands will appreciate the knock and in the long run, better gas will cost less than an engine.
I would assume with the advent of technology like i-VTEC the ECU's were already 'adjusting' for people putting whatever gas in that they felt they could afford.
But it's trying to run at tune, relying on knock sensors, then cutting timing. I wonder what the tune octane is. I know my ILX runs better and gets better mpg's on 92 than on 91.
I'm assuming anything above the tune octane would be a waste.
But it's trying to run at tune, relying on knock sensors, then cutting timing. I wonder what the tune octane is. I know my ILX runs better and gets better mpg's on 92 than on 91.
I'm assuming anything above the tune octane would be a waste.
True. Some of you can get 93. My area is only 91. Never seen 93 at the station. We can assume 91, but is it really..
I would assume with the advent of technology like i-VTEC the ECU's were already 'adjusting' for people putting whatever gas in that they felt they could afford.
By the time a modern knock sensor picks up detonation strong enough to retard timing, you've already put quite a bit of stress on the motor. If they suggest you run premium, run it. If you somehow are so broke you can't afford an extra $2 a fill up, then don't run the car hard or use a heavy foot under load.
You sir, are correct, if $6 breaks your bank, you need to rethink your priorities!
I hope my thread is not a reflex of threads from 15 years ago where as young men, we debate about spending more, on gas. I wish manufactures would provide this info, straight up. Would you believe me if I said a Lexus product planner told me it was ok to use 87 on a IS250? We all know it can. That's how you do marking and product placement.
I hope my thread is not a reflex of threads from 15 years ago where as young men, we debate about spending more, on gas. I wish manufactures would provide this info, straight up. Would you believe me if I said a Lexus product planner told me it was ok to use 87 on a IS250? We all know it can. That's how you do marking and product placement.
Ok, I'll bite... so lets say that you and your Lexus buddy are correct. Last I checked, a Lexus and a Honda are two different brands... and are tuned differently... so making the leap that because it is "safe" for a Lexus, it will also be safe for a Honda is very presumptive. Multiple people with vast knowledge have told you how this particular system works... and you don't like the answers.
Scientifically, the engine CAN run on 87 octane fuel. Can it run at optimum performance and produce maximum power on 87 octane when rated for 91 or 93... absolutely not. The subsystems like knock retard were invented for dummies and cheap asses who ignored the warnings/recommendations from the manufacturer and put substandard fuel into their cars without understanding the damage this decision can inflict. These subsystems are necessary to save this legion of idiots from themselves. I suggest you put aside the blather from your Lexus pal and do some research on octane, knock, static compression and effective/dynamic compression. Once you fully understand these, I believe you will see the error in your hypothesis.
We own a Sport hatch, and on page 113 of the owner's manual it merely states minimum 87 octane, and no more than 15% ethanol. It does say that models that state "premium fuel recommended" should use 91 octane premium fuel.
Guess what?
Our Sport hatch says "Premium Recommended" on the inside of the gas door. I just went out and checked, and I'd not even seen it before. Good thing we've been using 93 octane, because the sales guys were pretty specific about it being able to run regular fuel LOL!
...none of this answers your question though - is it tuned for 87, or 91, or even 93?
I'd reach out to someone from Hondata or K Tuner, and ask if they could tell what the base map indicates. They'd probably have the best idea.
Why wouldn't we believe that? We are talking about a Honda 1.5 turbo motor with a quite a bit of boost. That's apples to oranges.
Good point as one is turbo and the other one not (2.5 V6).
Along that line, I wonder if VW's 1.8L Turbo (current Passat) is the same way. 87 is the recommended fuel (to be marketable), but it's really tuned for premium.
My 2016 Civic Turbo does make more power on Chevron 94. The performance increase is noticeable in the "S" transmission selection. My conclusion is there are energy differences between grades, particularly in the Ethanol blends. The effect is maybe at the 2 - 4% level. Also there can be an effect from oxydized fuel. The Chevron 94 that I use is very fresh, and is produced about 20 miles away in Burnaby BC, and is then barged by Chevron's own barge to a tank farm 5 miles away, and then delivered to the station by their own (captive) contractor. This fuel is very popular and is known for performance and for correcting driveability issues. The 94 pumps are just mobbed on weekends by motorcyclists (I use it in all my bikes including my collector Hondas), ATVers, boaters, snowmobilers, etc.
Not that old thread but, all crap of opinions. Facts are what matter, not opinions.
1. "Premium recommended" means 91+ is better but you can use 86 if you want to. Obviously you won't get the max power out of the engine. It won't break the engine or put any more stress on the engine. If you are always pushing it hard and high reving, that put a lot of stress on the engine, but even that the engine should support and hold entirely. New ECU's are tuned in a form that they can detect and "learn" what kind of fuel you are and adjust the tuning for that. Also, the ECU "learn" how you drive...
A true recommendation is don't change fuel type every time you fill the tank.
2. Higher octane rating does not mean that the fuel have "more energy." Is likely the same gasoline. It may be a higher quality because a premium product,, but it really means that it's less likely for knocking and detonation (self ignition).
E-85 or ethanol does have higher octane rating than gasoline, but also have less energy content. If you run a car with E-85 it will burn more gallons of fuel, lower mileage. Thats prooves that higher octane rating does not mean more energy.
3. Engines are not "rated" for an octane rating. The octane rating is a rating for the fuel. Engines are designed to use a fuel type and with certain octane rating.
Conclusion: these new engines/ECU's/cars are designed so you can use different fuels. Is safe to use 86,87,91,93. If you plan to use for normal driving use 86/87 or what you have for less $$$. If want to waste some $2-4 extra fill with 91-93. If some day you plan to go to the track, empty the tank, fill with premium and drive it in all conditions (idle, normal driving, high revs) so that the ECU can adjust. Then enjoy your day at the track.
Your opinions are full of ****. Saying that the engine will blow and using regular fuel put stress and a lot of other ****. If what I put is full of ****, well don't blame me. Blame the manufacturer who is the one that said that you can use regular gas on that car.
Nowhere did I say the engine will blow. I said you can put added stress on the motor. The new civics knock sensor will not adjust until it gets repeated knock signals. So if you run premium then throw in 87 it will take multiple drive cycles to change the map. Same holds true to going from 87 to 91/93. This is why they recommend premium fuel.
07-23-2017, 09:34 AM
1.5 Sport engine HB and premium fuel
