Higher octane gas for fuel pinging

My 2002 Camry pinged on climbs since new. I drove it for 160K miles until it was totaled by an uninsured driver last month. Motor still ran smooth as silk.

I would not worry about it. The manual does state some pinging under load is normal.

 

How long has this been happening? The reason I ask is that it could be poor quality of gas if it has been happening recently. Had this happen a few years back on my old Baja when buying gas at one of the cheap gas stations. A friend suggested getting better quality gas, and the pinging was gone!

 

That's odd. My G2 started pinging this year (filling with 93 octane at half-tank seems to have "fixed" it) but it has 91,000 miles on it and it never pinged before. I'm assuming that mine is partially due to carbon buildup, and exacerbated by hot weather. A 2012 shouldn't have had time for that to happen.

If anything my FE us up a couple MPG since the partial fill with 93. Higher octane shouldn't hurt anything mechanically. Pinging, on the other hand, isn't great for an engine. Uncontrolled combustion drives up cylinder temperatures and puts increased loads on just about everything. It shouldn't immediately grenade an engine, either, but I wouldn't just ignore it.

 

I hear the same thing in my 2012. I thought it was pinging at first too, but now I don’t think it is. I tried some higher octane fuel, and it made no difference. I noticed that it only happens in a narrow band of RPMs, in the middle of the PWR bar on the display. Pinging will normally get worse with load; this sound will go away if you increase throttle or decrease throttle when you hear it. This is not how pinging behaves. I think this is a natural sound from the lifters and valves that hits a resonant frequency in the engine compartment at a certain number of RPMs and travels into the cabin, but only at that frequency. If the frequency goes up or down it is no longer resonant and therefor it disappears. Also higher octane fuel is not recommended for the Prius as it is not a high compression engine.

 

The other thing to remember is that the Prius has a "ping" detector that is supposed to adjust the engine to stop pre-detonation if it is detected.

 

A knock sensor to retard the timing as needed. If the knock sensor is bad or disconnected, a code would be stored and the CEL would come on. Running an engine as advanced as possible improves efficiency, and also increases the possibility of light pinging under load.

 

There should be no problem with 91 high octane gasoline in the Prius, could help not hurt MPG.
The question is should you use it, from a cost perspective? I would try a tankfull to see if it solves the problem. If it does, that tells you something. I am sure you can buy a can of gaso additive with octance boost + detergents. Not sure what elevation you have there, mountain regions may have different fuels. If you see a benefit of higher octane then we can discuss what may be happening (possibly low M+0 octane in your region).

 

You might have a bad tank of gas; some water in it. You might try Berryman B-12 CHEMTOOL!! It's good for removing moisture, and it also cleans valves, injectors, ect.

 

Most octane boosters use ethanol to boost the octane, there is most likely more than enough of that crap in your gas as it is, I wouldn’t use it. If you think you might need some detergent in your tank try some Techron additive. While a tank or two of the higher octane gas won’t hurt as a test to see if your pinging noise changes, I wouldn’t use it unless you get an OK from a mechanic who knows the Prius. The Prius engine is designed to run on 87 octane fuel; 85 octane if you are at higher elevations. As I recall the manual doesn’t recommend using higher octane gas. The computer will just try and adjust for any changes in octane anyway. Higher octane fuel should only help when run in older high compression engines. By the way, higher octane gas doesn't mean its better, all it means is that it is less likely to combust early when highly compressed. The Prius engine doesn't use anywhere near the compression levels of older high performance engines, thus you don't need it. Also if you search PC you will find some folks who feel using higher octane gas has actually hurt their Prius engines. I don't knowif this is true, but if it is, it could void your warranty, as the manual says not to use it. Just my 2 cents FWIW.

 

OP should of course look in his Gen-3 Prius op manual for any octane limits.
My gen-2 manual says 87 minimum octane (R+M/2)
I'm sure I've accidentally used Premium more than once.
If Premium hurt the car we'd be in trouble for accidental .

 

FWIW I used 89 octane in my 2nd gen for the same reason.

PC36100 ? 2

 

Things might have changed, but in the past, when a place like Circle K would purchase it's gas from Union 76, Shell or Cheveron, they would be purchasing the gas without the additives. I have no idea how that otherwise affects the quality of the gas (which I think shouldn't).

Mike