Spark plug heat range question
 

I remember my old auto/body shop teacher used to say to use hotter plugs for
short-trip, around town driving and colder plugs for extended freeway driving.
I'm doing mostly short-trip around town driving w/my '91' XJ now and have
noticed a gas mileage drop, would going to hotter plugs make any difference?
Would the engine get up to operating temp faster w/hotter plugs?
-Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Use only the recommended plug. Going to a hotter plug without some
investigation of what would work first could result in serious piston
damage... as in burnt holes in the piston tops.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Use only the recommended plug. Going to a hotter plug without some
investigation of what would work first could result in serious piston
damage... as in burnt holes in the piston tops.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Use only the recommended plug. Going to a hotter plug without some
investigation of what would work first could result in serious piston
damage... as in burnt holes in the piston tops.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Hotter/colder plug ratings refer to the operating temperatrure of the plug,
they have nothing to due with the engine operating temperature.
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
> I remember my old auto/body shop teacher used to say to use hotter plugs
for
> short-trip, around town driving and colder plugs for extended freeway
driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Hotter/colder plug ratings refer to the operating temperatrure of the plug,
they have nothing to due with the engine operating temperature.
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
> I remember my old auto/body shop teacher used to say to use hotter plugs
for
> short-trip, around town driving and colder plugs for extended freeway
driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

Hotter/colder plug ratings refer to the operating temperatrure of the plug,
they have nothing to due with the engine operating temperature.
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
> I remember my old auto/body shop teacher used to say to use hotter plugs
for
> short-trip, around town driving and colder plugs for extended freeway
driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

I think plugs work (self clean without burning up) between 450-800
degrees. Hotter plugs have a longer nose into the cylinder and don't let it
transfer heat as fast. Short trips and low speed May keep the plug temp
lower and highway driving May keep the temp higher in the range. But, the
factory plugs should have a range that'll do just fine for both. Too cold
and it'll gum up; too hot and it'll burn up.
The best way to check is to pull a plug (checking all at the same time's
best) and "read" it. If it's black and sooty, it's too cold (can't get hot
enough to burn it off). If it's bone white, blistered; too hot (cleaned in
a blast furnace). Tan... it's a beautiful thing. This one's just right.
Here's a good link for a more in-depth explanation:
http://www.centuryperformance.com/spark.asp
Jim
P.S. See Bill? I do some homework before I ask how to gap a spark plug:)
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

I think plugs work (self clean without burning up) between 450-800
degrees. Hotter plugs have a longer nose into the cylinder and don't let it
transfer heat as fast. Short trips and low speed May keep the plug temp
lower and highway driving May keep the temp higher in the range. But, the
factory plugs should have a range that'll do just fine for both. Too cold
and it'll gum up; too hot and it'll burn up.
The best way to check is to pull a plug (checking all at the same time's
best) and "read" it. If it's black and sooty, it's too cold (can't get hot
enough to burn it off). If it's bone white, blistered; too hot (cleaned in
a blast furnace). Tan... it's a beautiful thing. This one's just right.
Here's a good link for a more in-depth explanation:
http://www.centuryperformance.com/spark.asp
Jim
P.S. See Bill? I do some homework before I ask how to gap a spark plug:)
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)

Re: Spark plug heat range question
 

I think plugs work (self clean without burning up) between 450-800
degrees. Hotter plugs have a longer nose into the cylinder and don't let it
transfer heat as fast. Short trips and low speed May keep the plug temp
lower and highway driving May keep the temp higher in the range. But, the
factory plugs should have a range that'll do just fine for both. Too cold
and it'll gum up; too hot and it'll burn up.
The best way to check is to pull a plug (checking all at the same time's
best) and "read" it. If it's black and sooty, it's too cold (can't get hot
enough to burn it off). If it's bone white, blistered; too hot (cleaned in
a blast furnace). Tan... it's a beautiful thing. This one's just right.
Here's a good link for a more in-depth explanation:
http://www.centuryperformance.com/spark.asp
Jim
P.S. See Bill? I do some homework before I ask how to gap a spark plug:)
"Wblane" <wblane@aol.combotizer> wrote in message
news:20041011122637.01525.00001827@mb-m17.aol.com...
>I remember my old auto/body shop teacher used to say to use hotter plugs
>for
> short-trip, around town driving and colder plugs for extended freeway
> driving.
> I'm doing mostly short-trip around town driving w/my '91' XJ now and have
> noticed a gas mileage drop, would going to hotter plugs make any
> difference?
> Would the engine get up to operating temp faster w/hotter plugs?
> -Bill (remove "botizer" to reply via email)