Can pinging be caused by certain gasoline brands?

For a few months earlier this year, my '93 Accord LX (Canadian, similar to
American DX) would make a very audible metallic pinging sound when I
accelerated. I figured that perhaps the ignition timing needed to be
adjusted (but I just didn't have the time to get it done).

I had been filling the tank with 87 octane gasoline from Canadian Tire during
this time. Before, I used to fill up at Esso, Shell, etc. and had no
pinging. When the pinging started, I tried higher octanes, but that did not
help. But the last few times I went for gas, I filled up at a Sunoco station
(again, 87 octane). And to my surprise, the pinging has been almost
completely eliminated. Sometimes I can just barely hear some light pinging
if the radio is off, the fan inside is on low speed, and the window is open
(whereas before I always heard it regardless of these settings).

So can anybody tell me if this was pure luck, or if some gasoline brands
(like Canadian Tire) can cause pinging in some engines regardless of octane?
The car currently has 208,000km (129,000 miles) on it if that matters.

Thanks in advance.

 

Canadian Tire gas is about the cheapest gas on the market. It just runs
dirty. So yes, improper gas will cause this problem. Stick with the big 3
gas stations, and you should not have this problem anymore.

Rick

 

Oh yeah, I almost forgot. A friend at work also had his bank car 'skimmed'
as a result of going to 2 separate Cdn Tire gas bars. From what I
understand, these gas bars are purchased franchises of Cdn Tire, and are not
run by the 'mother-company'. Obviously, I'm not saying all of these gas bars
are crooked, but as if you needed a better reason not to go there than cheap
gas.

 

Some brands of gas are indeed worse than others. Use what works.

 

Especially with an older car, where there may be some carbon build-up in
the combustion chambers, you can be right on the "jagged edge" of
preignition with a gasoline which is just within spec. It can also be
affected by factors like temperature/humidity which can push it slightly
one way or the other. Gasoline is not a precision product and is a mixture
of many different chemical compounds, so there is some slop in whether it
burns right in any given engine under varying conditions. E.g. even though
the whole gasoline meets spec, the volatile and less volatile components in
the gasoline can have different octane ratings, one slightly above and the
other slightly below spec. and under certain conditions it will ping
slightly. There *are* tests/specs which measure the volatile component
separately but again due it's make up, those can only measure a specific
fraction... which may not be the one which fits your conditions/engine.

Not living in Canada, I don't know Canadian Tire but I assume they are not
a refiner so are buying in bulk from wherever they can get the stuff. It's
possible that they have their own additive package which is not as good or
they are less than fastidious about putting the right stuff in the correct
storage tanks. If the gas is oxygenated with alcohol where you live that
could also affect things - the refiners have found that it has a very short
storage life (the alcohol "draws" in water from the atmosphere) and only
add the alcohol at the very last minute before loading to the road-car for
delivery. Personally I'd pay the extra $ or so per tank to avoid
pinging... and maybe report this to your local Weights & Measures authority
if it exists... and maybe your local TV news consumer advocate.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??