Any harm in using higher octane?

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My Accord has a ping here or there occasionally when going up hills, moderate acceleration etc. I use our local Shell station and its stays very busy, so it always has "fresh" fuel. About a month ago it was pinging almost any time you would accelerate rapidly or go up a hill, but I am thinking that was just a bad tank of fuel. Now its just a couple pings even now and again. My question is, would there be any harm in using a higher grade of fuel than recommended? This should stop the occasional pinging, but I have read that higher octane than necessary can leave more deposits behind and will not burn as clean as it should due to being more resistant to ignition. Can anyone confirm this?
 
Just found this in the owners manual: Your vehicle is designed to operate on unleaded gasoline with a pump octane number of 87 or higher. Use of a lower octane gasoline can cause a persistent, heavy, metallic rapping noise that can lead to engine damage.

Is says its designed to use 87 or higher, I just have to wonder, if deposits are truly an issue then my short trip driving style wont help matters any.
 
Originally Posted By: andyd
Just to your wallet. Wabbout trying another gas station?


Well, the thing is the only other top tier station in our area is a Exxon station that was just converted from an old no name place. It has like two pumps and doesn't stay busy. And I dont want to use any non top tier stations. In fact, I have NEVER used any non top tier stations.
 
If you can hear the pings then your knock sensor may be defective. It should be retarding your timing before they're even audible.

Also, I'd start looking for an air leak on the intake area/vacuum system.
 
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My wife has the same car.

RaceTrac 87 octane + a bottle of Techron once a year is all we do. No top tier gas necessary in that Honda.
 
My truck, despite being flex fuel, does not seem to like high octane gas. Odd, because it runs beautifully on roughly 105 octane E85, and runs beautifully on 87 regular. I put a tank of 93 octane Shell in it not too long ago, and I could feel it pull the timing (I think that's what was going on). It still ran smoothy, but definitely did not like the 93 octane compared to either E85 or 87. It knows (I guess based on the O2 sensors, no "ethanol sensor" on this one) whether or not it has ethanol in the tank. I didn't run the 93 because of pinging, just out of curiosity to see what kind of MPG I would get (no noticeable difference there).

If you have abnormal pinging, I would try to figure out the cause rather than try to band aid it with higher octane fuel. Some sporadic pinging is normal on many modern engines. Maybe you are noticing it more now since you had that one bad tank and are looking for it?
 
The only gas I have ever purchased since getting my S60R in August of 2007 and now my GT is Shell V-Power. it is only an extra $3 or so a fill-up for 91 octane vs 87.
 
Use the highest octane needed to stop ping. It is false that the knock sensor will hear it and retard the timing before you do. If its only faint it might but generally if it pings you will hear it briefly also.

If it is pinging and retarding timing you are giving up power for the sake of running low octane fuel and it might be causing the fuel economy to take a hit.
No deposit issues from running higher octane. Try 89.
 
If its pinging at all running 87 in that car you need to fix the problem, not mask it by running higher octane fuel.
 
Originally Posted By: Trav
Use the highest octane needed to stop ping. It is false that the knock sensor will hear it and retard the timing before you do. If its only faint it might but generally if it pings you will hear it briefly also.

If it is pinging and retarding timing you are giving up power for the sake of running low octane fuel and it might be causing the fuel economy to take a hit.
No deposit issues from running higher octane. Try 89.


I agree try a tank of 89..if same trouble try a full tank of 93..it wont be expensive to test that out, even if you go back to 87 octane after. Sometimes I run the odd tank of 93 for kicks or when im going on a drive thats hilly etc..granted the 4 in the Corolla is weak to start with. Might make no difference at all but i dont care.
 
Originally Posted By: Jimzz
If its pinging at all running 87 in that car you need to fix the problem, not mask it by running higher octane fuel.

What problem???
 
It's not unusual to have engines tuned to extract as much as possible from a particular octane to build up enough carbon over time to raise the requirement a point or to. The timing reduction caused by the knock sensor may not be noticed by the aveage driver. Going from 87 to 89 is usually enough on an 87 octane engine to correct the slight hesitation caused by timing retardation. Having to go from 89 to 93 is a big enough jump that it suggests something more than carbon buildup is at work.
As an aside, I'm seeing 30 to 40 cent price differences between 87 and 89 in these parts. I doubt the cost making 89 is THAT much higher, profit margin included.
 
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You don't have to go all super. You could just try a few gallons of super with regular to bring up the average octane in the tank. That's how they make plus anyway, they mix regular and super. Mix would be 1/3 super to 2/3 regular with 93 super.
 
I am betting you have some carbon to burn off.
I would run a tank of 89, with a (Big......20oz) bottle of Techron, and give it a daily "Italian tuneup" while running through that tank. Then, back to 87, and continue the daily "Tuneups".
 
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