Higher octane gas for fuel pinging

I was reading in a South Dakota newspaper this past week about refineries out west producing 81.5 & 85 octane gas. They are trying to force South Dakota to switch from 87 octane to one of the lower grades gasoline. I have a sneakin suspicion that you are getting into some of that low grade gasoline. No way will 92 or higher octane gas hurt your motor. Run what you want in the car. It will even run on E57 blends but many will say your fuel system will rot away and fall off the car so don't do it I run the good stuff in my car, it cost too much to use cheep gas in it.

Mike

 

Start using Shell or 76 gas for a few tank-fuls, keep using these if you can. Chevron has Premium won't harm anything, but it will have more detergent agents for cleaning fuel systems. Also try the Berryman Chemtool cleaner. You may have some water in your tank from a bad load of gas to the Circle-K, and you'll have to flush the contaminant out.

Altitude doesn't help, but I haven't noticed any knocking noises crossing passes here higher than 2500 ft. I think your problem is contaminated gas.

 

I've had slightly poorer mileage with Chevron, fyi. I mostly use Shell.

 

I have never heard that sound before. It is definitely not engine pinging.

 

That sounds more like a loose/worn belt, but you don't have any belts.

Does it make the noise when you rev the engine in Park or Neutral?

Does the noise change if you're accelerating around a corner, either left or right?

 

I have talked with Toyota about gas to use and apparently the Prius can be very finicky. Have to use good 87 grade gas. They told me that anything above 87 the Prius won't use as efficiently I used Citgo for awhile. Things weren't bad. Made a mistake of putting some generic truck stop 87 in and omg!!! Not good!!! Ping ping!! Took many good fill ups of Sunoco and car runs beautifully. Now I make sure to stick with good stuff. Also heard Shell and Mobile are good. BP gas is a ok one in a pinch

 

Dudes, all gas for your city comes from the same terminal. They dump the brand specific additives in there as the tanker hauls it off to a station. There is some varibles in how well a station is run (freshness, clean tanks, water leaks, filter changes, etc). Other than that, gas is gas, sans the little additive they put in.

Personally, I stick with WalMart / Murphy USA, because they are cheaper and move a lot of gas, so their gas is more likely fresh and tank cleaner, compare to some mom and pop shop in the woods.

 

...lost a post, but the chirping sound may or may not be knocking.
If you put Premium in there and you still have the sound, then it is probably not knocking.
Octane rating should be listed on the pump.

 

If your car is pinging, like my old cars did back in the old days, your computer
controlled emission system should flash a warning light on the dash. If
no check engine light was activated perhaps it may not be a emission
control issue.