uphill, with a/c, high altitude, & a trailer: use premium gas?
07-31-2004, 01:38 PM
#41
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
A Colorado Cherokee has this in the build list: "Emissions - High
Altitude Tracking".
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
twaldron wrote:
>
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
Altitude Tracking".
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/
twaldron wrote:
>
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
07-31-2004, 02:37 PM
#42
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
On Sat, 31 Jul 2004 05:07:53 UTC handywired@aol.com (Handywired)
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
07-31-2004, 02:37 PM
#43
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
On Sat, 31 Jul 2004 05:07:53 UTC handywired@aol.com (Handywired)
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
07-31-2004, 02:37 PM
#44
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
On Sat, 31 Jul 2004 05:07:53 UTC handywired@aol.com (Handywired)
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
07-31-2004, 02:37 PM
#45
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
On Sat, 31 Jul 2004 05:07:53 UTC handywired@aol.com (Handywired)
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
wrote:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
Strictly anecdotal, but I would seriously consider going up one grade
because of a simple test. The older 4.0 MPI included a knock sensor,
which essentially retards the spark when it signals the computer of a
knock. If I leave Colorado Springs and head over to the western slope
over some 10-11,000 foot passes I can see a definite difference in how
I pull the long grades. That indicates to me that the computer is
detecting some amount of ping and retarding the timing to some degree
resulting in a little less power with the 85 octane - but it's enough
to have me down shifting pretty often. Of course, having 3.07 diffs
doesn't help in the least, but I see a definite difference. One grade
in particular shows a consistant difference that grabs my attention:
the pull up the west approach to Eisenhower tunnel. There are places
where I will wind up in 3rd to hold speed with regular (85 octane)
while using the midgrade (87) I pull the whole climb without lugging
in 4th (forget 5th if there is a hill in sight once you get above
about 3000 feet).
Now, the higher octane does not provide any more energy, it simply
allows the engine to work a little harder without pinging. The only
way I'm seeing better power with the higher octane pretty much has to
be the knock sensor effect. I think that some owners manuals do, in
fact, suggest using the higher octane for towing and moutainous
terraine - at least the 88 manual does.
--
Will Honea
07-31-2004, 07:37 PM
#46
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
Ford manuals have the notation on not using the low (86 and less) octane.
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
07-31-2004, 07:37 PM
#47
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
Ford manuals have the notation on not using the low (86 and less) octane.
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
07-31-2004, 07:37 PM
#48
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
Ford manuals have the notation on not using the low (86 and less) octane.
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
07-31-2004, 07:37 PM
#49
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
Ford manuals have the notation on not using the low (86 and less) octane.
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
twaldron wrote:
> Which owner's manual and what octane are you talking about?
> DC recommends 87, Reg. Unleaded or "low" octane (compared to MID and
> SUPER) for the newer Jeeps.
>
> RoyJ wrote:
>
>> The owner's manual doesn't reccomend the lower octane for late model
>> engines. Something about the various sensors not givng the computer
>> the correct info. Not sure which one might be involved, the O2 sensor
>> should be happy no matter what. Might be the MAF sensor.
>
>
07-31-2004, 08:50 PM
#50
Guest
Posts: n/a
Re: uphill, with a/c, high altitude, & a trailer: use premium gas?
Handywired proclaimed:
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
You can probably lower the octane. Less chance of pinging at high
altitude--actually ran into some "regular" this last trip that was
only 85 octane. However, I've noticed a bit more ping with "bush
gas" and regular, so tend to use midgrade on cross country trips.
> .... in my 4.0L TJ?
>
> Manual says use 87 octane and that's just great. Should I up the octane any as
> I head up to 6K feet with my family, a camping trailer, the A/C blowin', etc?
You can probably lower the octane. Less chance of pinging at high
altitude--actually ran into some "regular" this last trip that was
only 85 octane. However, I've noticed a bit more ping with "bush
gas" and regular, so tend to use midgrade on cross country trips.