aklim

Perhaps you are in the right direction. It has to have a certain intensity BUT also fall in that frequency spectrum otherwise it doesn't register. Makes sense otherwise it may pick up all kinds of engine and road noise.

84 4+3

I would guess a metal screwdriver is close to something knocking on a bearing... Metal on Metal and such.

AirForceOne!

I've been running premium gas with 10%methanol for 6 years now and never had any problems what-so ever

kenmohr

me too! since 2007

Tom400CFI

Finally got around to doing a little looking. This is on a '92 LT1, 85 octane -the "cheapest"/"worst" you can get. All photos were taken when climbing a hill, and in a high gear; 5th or 6th gear. I was able to see/capture one knock event....

JimLentz

A working principle to piezoelectric elements involves the transmission of an electrical current in response to detecting a change in pressure or vibration by these elements. The piezoelectric element inside the knock sensor is tuned to detect the engine knock/detonation frequency.Sep 6, 2012

RalfKramden

FWIW, the original owners manual states "Your engine is designed to operate on premium grade unleaded fuel,
However, with the electronic spark control system you may use either middle or regular grade fuel at slightly reduced acceleration performance.

84wuzmy1st

I only use non-ethanol 89 Octane from Wawa in my 85.

Tom400CFI

We know. The question was whether the OP could make it across the country w/o destroying his engine. I'm sort of kidding, of course he can, but would it use more fuel due to knock retard. Veteran posters here said to actually look for knock with a scanner. I did that, and basically had none. Seems like more of that "**** that ain't worth worryin' about." Especially for a guy (the OP) driving across country.

cdm747

Yeah - I posted that same quote from the owner's manual back in Post 26. It doesn't say it is going to hurt anything. In reality it says you can use what ever grade YOU want. Just use what makes you happy and keep on trucking.

pologreen1

Nice work, Tom!

The only time higher fuel octane is an issue is
-Real old cars with leaded in mind
-Cars with high 11.0+ compression
-Forced induction

That being said if I have a vette that is stock I still would run 91-93 that is just me. A cheapskate can, will, and do get away just fine with 87.

Imagine the lawsuits, warranty claims, and issues if manufactures actually made things designed for specific use? So many of these production cars would be toast. Consumers are proven idiots, manufactures take that in to account when engineering their products.

You can always count on people trying to do something to cheat at something, what ever the context.

Tom400CFI

THanks! Note that I was actually running 85 octane for this little test. On the one hadn't, I'm at high elevation -so less pressure at WOT...but the test wasn't WOT, it was regular driving, up hills mostly. Plenum pressure has to be the same, to achieve the same tq to go up a given hill, so atmosphere doesn't matter much under the conditions for this test.

kenmohr

My 2 cents. Even one knock is like hitting your valve and piston with a hammer. Premium is cheap insurance. Even though I never ever ever ever go more than 1/4 throttle.

aklim

If that is all you are doing, you are probably not going to hit detonation. That is over insured. OTOH, if multiple WOT runs are in your future, I would.

Mr. Bear

Thank you. I live in Md & up & down the east coast there's usually at least a $.60-$.85 per gallon difference between 87 & 93 octane. In some areas the difference is even greater. I wish I could find a 20 cent difference between 87 & 89 octanes.