low octane hard on knock sensor

[TG]

A friend of mine had his 3rd generation Outback's knock sensor replaced and
they told him to use higher octane fuel because the other stuff was hard on
the sensor.
I believe that the vehicle probably needs a higher octane fuel but I don't
think even the lowest octane available for sale in the states would actually
damage the sensor...am I wrong. Thanks. TG

 

[Nick Lamendola]

I don't think low octane fuel would damage a knock sensor. I guy I work with
used to work on high end european cars. He said they never saw knock sensor
fail. It was usually just corrosion causing a bad connection to ground. The
sensor only has one wire and relies a a good ground for the second
connection. A new sensor has a bright clean surface but the engine surface
where the sensor is bolted to may still be oxidized, so a new sensor works
for a while and then goes bad. How long between sensor failures on your
friend's car?

I just replaced my sensor, wish I had just tried sanding the bottom of the
old sensor, I would have saved $90. If the new sensor fails soon I will try
just cleaning the sensor and mounting point.

-Nick L

 

[Mark H]

A friend of mine had his 3rd generation Outback's knock sensor replaced
and

they told him to use higher octane fuel because the other stuff was hard on
the sensor.
I believe that the vehicle probably needs a higher octane fuel but I don't
think even the lowest octane available for sale in the states would actually
damage the sensor...am I wrong. Thanks. TG

you get what, 87RON fuel?
Unless the subies over there are significantly detuned, you'd need the best
you have.

We get 98RON in Aus, even 95 gets the Forester pinging - used once out of
necessity.
Our lowest is 91RON, wouldn't dream of putting that in, let alone lower.

-mark

 

[Jim Stewart]

you get what, 87RON fuel?
Unless the subies over there are significantly detuned, you'd need the best
you have.

We get 98RON in Aus, even 95 gets the Forester pinging - used once out of
necessity.
Our lowest is 91RON, wouldn't dream of putting that in, let alone lower.

Standard in California is 89-91-93 octane. I
don't know whether or not the numbers are directly
compatible wiht RON.

I've ran 91 since day one and haven't had any
problems with knock or performance. I do use
a brand known for quality and high detergent
levels though.

 

[the one and only]

I've ran 91 since day one and haven't had any
problems with knock or performance. I do use
a brand known for quality and high detergent
levels though.

And which brand is that?? may I ask??

 

[JD]

--
---------------------------------------------------------------------
Good health is simply the slowest way to die.

John

Standard in California is 89-91-93 octane. I
don't know whether or not the numbers are directly
compatible wiht RON.

Its not. The 98 RON in Aus is about 93 AKI (r+m/2). Their high test is the
same as it is on this side of the pond.

 

[JD]

--
---------------------------------------------------------------------
Good health is simply the slowest way to die.

John

you get what, 87RON fuel?
Unless the subies over there are significantly detuned, you'd need the
best
you have.

We get 98RON in Aus, even 95 gets the Forester pinging - used once out of
necessity.
Our lowest is 91RON, wouldn't dream of putting that in, let alone lower.

-mark

We don't use RON in N. America. We use AKI; which is (r+m)/2. 87 AKI, our
lowest grade, is about 92 RON, and 94 AKI, available in some parts of
Canada, is a little over 99 RON. Most places can get 92 or 93 AKI which is
very close to the 98 RON you have in Aus

 

[Mark H]

We don't use RON in N. America. We use AKI; which is (r+m)/2. 87 AKI,
our

lowest grade, is about 92 RON, and 94 AKI, available in some parts of
Canada, is a little over 99 RON. Most places can get 92 or 93 AKI which is
very close to the 98 RON you have in Aus

Fair enough.
I'd still only be putting in enough mid-grade to get to the next servo that
sells high-grade.

-mark

 

[hippo]

hard
on

you get what, 87RON fuel?
Unless the subies over there are significantly detuned, you'd need the
best
you have.

We get 98RON in Aus, even 95 gets the Forester pinging - used once out of
necessity.
Our lowest is 91RON, wouldn't dream of putting that in, let alone lower.

-mark

Why? My 91 Liberty wagon (332000km) and 99 OB Ltd
(135000km) are both labelled 90RON or better. Both run fine on 92 and no,
neither of us drive like grannies! Incidentally the OB gets marginally
WORSE mileage on 98RON than anything else - which is something I've never
encountered before! Cheers