Thanks all. I did check my oil level (embarrassed to say this is the first time I opened the hood since I have had it), and it is fine.

I am going to switch to using Shell. I have located a station that is not much further away than the cheapo Crown station. I used to be hesitant to use Shell cause in the 80s I had a Maxima that ran better when it did not use Shell. I will give it a try again. I still don't buy Exxon because I am still mad at them for what they did in Alaska.

Since I work at home, I fill up only once a month anyways.

I will report whether this continues to occur.

It's 85 for a reason, you are probably up very high (altitude wise). No need to retard detonation when the lack of oxygen already does that for you.

Exxon... me too... only I buy Mobil every now and then so I can't escape from them completely.

Very simple, try higher grade and see if it goes away. Another thing you could try is Italian tunning, step on accelerator and gun the engine to full RPM's few times, poor quality gas and low engine workload could put some deposits inside cylinders, high RPM could blow some of it away and make the pinging go away, if it is pinging.

Sunday I was driving around a residential neighborhood with the windows down and noticed rather loud engine pinging. The TCH was warmed up - I had driven about 10 miles. The temperature was only 70F and I have been using Shell gas for some time. Light pinging would not bother me, but this was bad. Normally I don't drive with the windows down, but it was a nice day and the ocean breeze was lovely.

I was going up a small hill, gently accelerating from a stop. As the car passed ~5 miles per hour the pinging started, and got rather bad by 10mph. Around 15 miles per hour it started to quite down. The engine rpm sounded just faster than an idle speed, but sounded like it was working - almost lugging. I tried the same hill a few times, and if I backed off the gas or accelerated faster, the pinging went away.

The TCH has 21,000 miles, and drives excellent. I'm thinking I may need to run some injector cleaner through the engine despite using good gas (mostly Shell and some Exxon) I'm going to try an re-create the pinging in a residential area near the dealer. If I can get it to ping consistently, I will have a Hybrid Tech from the Dealer ride along and see what they say.

Has anyone noticed any pinging on their TCH? I doubt I would have heard it with the windows up and radio playing...

Just got a bad batch of fuel, happens a lot lately! careless at the refineries. I test every drop in the aircraft and varies dailey, on the TCH the knock sensor should retard the spark when detonation is sensed may have a bad sensor also.

TCH-43mpg
VW TDI--48
08 LS 600 HL-20
08 LX 470-16

I have been advised by several mechanics not to use injector cleaners as it causes more harm than good. As far as pinging, add some hi octane gas when the tank get down to half full and see how it sounds

I've had no pings at 4800 miles, always using 87 octane.

My last little Corolla, and my wife's, needed premium or the engines would sound like a metal box full of loose nuts and bolts. We learned to avoid that quick!

Seems I heard of other earlier Toyota models acting the same way no matter what the mechanics tried. Sure is nice to have a big honking TCH running on regular! My wife's '06 Corolla likes regular gas just fine, too.

I've had what felt like lugging, but no pinging, on 87. I'm trying 2nd tank of 89 now, restarts seems much smoother and settled.

They haven't rated fuels recently but a few years back Consumer Reports did test the national brands and Shell came out as being crap. I've stayed away from it just for that reason.