Dude your driving a J**P not a riced out Honda P.O.S., if you want better
mileage then take the advice of others and sell it, buy a Geo.

Snow...

"munchiechee" <munchiechee@sbcglobal.net> wrote in message
news:cb153bd2.0408212159.54b21140@posting.google.c om...
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

Dude your driving a J**P not a riced out Honda P.O.S., if you want better
mileage then take the advice of others and sell it, buy a Geo.

Snow...

"munchiechee" <munchiechee@sbcglobal.net> wrote in message
news:cb153bd2.0408212159.54b21140@posting.google.c om...
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

Dude your driving a J**P not a riced out Honda P.O.S., if you want better
mileage then take the advice of others and sell it, buy a Geo.

Snow...

"munchiechee" <munchiechee@sbcglobal.net> wrote in message
news:cb153bd2.0408212159.54b21140@posting.google.c om...
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

The short answer is no.

In my experience the aerodynamics are the mileage factor.

No matter the engine or the load they all get about the same mileage.
It depends on your foot and the speed you want to run and/or the 'RPM'.

If I am running at a GPS checked 'real' 65 mph in 5th gear, my 33" tires
keep my rpm down to about 1600 or so. It then sucks gas big time and I
get down near 15 or 16 mpg. If I drop down to 4th gear at 65 mph and
keep my rpm in the/my engine's 'sweet spot' of 2300 rpm, I get a
consistent 23 mpg or 11 L/100km. I checked this a couple weeks ago
running fully loaded for camping.

Then come gas differences!!!

If I run on 'real' gasoline, my mileage always stays up way over 20
mpg. If I run on any kind of alcohol or ethanol mix like my owners
manual warns 'not' to do unless in an emergency because you are out of
gas, my mileage is almost cut in half. The manual says the mix may
'degrade performance' before rotting out the fuel system. LOL! Yup, it
'sure' does degrade performance.

Have you checked your speedometer/odometer for accuracy?

Mine went 100% right on my CJ7 when I put 33's on it and it went 100%
right on my Cherokee when I put 235's on it. That make a difference in
the perceived vs real mpg....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

munchiechee wrote:
>
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

The short answer is no.

In my experience the aerodynamics are the mileage factor.

No matter the engine or the load they all get about the same mileage.
It depends on your foot and the speed you want to run and/or the 'RPM'.

If I am running at a GPS checked 'real' 65 mph in 5th gear, my 33" tires
keep my rpm down to about 1600 or so. It then sucks gas big time and I
get down near 15 or 16 mpg. If I drop down to 4th gear at 65 mph and
keep my rpm in the/my engine's 'sweet spot' of 2300 rpm, I get a
consistent 23 mpg or 11 L/100km. I checked this a couple weeks ago
running fully loaded for camping.

Then come gas differences!!!

If I run on 'real' gasoline, my mileage always stays up way over 20
mpg. If I run on any kind of alcohol or ethanol mix like my owners
manual warns 'not' to do unless in an emergency because you are out of
gas, my mileage is almost cut in half. The manual says the mix may
'degrade performance' before rotting out the fuel system. LOL! Yup, it
'sure' does degrade performance.

Have you checked your speedometer/odometer for accuracy?

Mine went 100% right on my CJ7 when I put 33's on it and it went 100%
right on my Cherokee when I put 235's on it. That make a difference in
the perceived vs real mpg....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

munchiechee wrote:
>
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

The short answer is no.

In my experience the aerodynamics are the mileage factor.

No matter the engine or the load they all get about the same mileage.
It depends on your foot and the speed you want to run and/or the 'RPM'.

If I am running at a GPS checked 'real' 65 mph in 5th gear, my 33" tires
keep my rpm down to about 1600 or so. It then sucks gas big time and I
get down near 15 or 16 mpg. If I drop down to 4th gear at 65 mph and
keep my rpm in the/my engine's 'sweet spot' of 2300 rpm, I get a
consistent 23 mpg or 11 L/100km. I checked this a couple weeks ago
running fully loaded for camping.

Then come gas differences!!!

If I run on 'real' gasoline, my mileage always stays up way over 20
mpg. If I run on any kind of alcohol or ethanol mix like my owners
manual warns 'not' to do unless in an emergency because you are out of
gas, my mileage is almost cut in half. The manual says the mix may
'degrade performance' before rotting out the fuel system. LOL! Yup, it
'sure' does degrade performance.

Have you checked your speedometer/odometer for accuracy?

Mine went 100% right on my CJ7 when I put 33's on it and it went 100%
right on my Cherokee when I put 235's on it. That make a difference in
the perceived vs real mpg....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

munchiechee wrote:
>
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

The short answer is no.

In my experience the aerodynamics are the mileage factor.

No matter the engine or the load they all get about the same mileage.
It depends on your foot and the speed you want to run and/or the 'RPM'.

If I am running at a GPS checked 'real' 65 mph in 5th gear, my 33" tires
keep my rpm down to about 1600 or so. It then sucks gas big time and I
get down near 15 or 16 mpg. If I drop down to 4th gear at 65 mph and
keep my rpm in the/my engine's 'sweet spot' of 2300 rpm, I get a
consistent 23 mpg or 11 L/100km. I checked this a couple weeks ago
running fully loaded for camping.

Then come gas differences!!!

If I run on 'real' gasoline, my mileage always stays up way over 20
mpg. If I run on any kind of alcohol or ethanol mix like my owners
manual warns 'not' to do unless in an emergency because you are out of
gas, my mileage is almost cut in half. The manual says the mix may
'degrade performance' before rotting out the fuel system. LOL! Yup, it
'sure' does degrade performance.

Have you checked your speedometer/odometer for accuracy?

Mine went 100% right on my CJ7 when I put 33's on it and it went 100%
right on my Cherokee when I put 235's on it. That make a difference in
the perceived vs real mpg....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

munchiechee wrote:
>
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.
>
> I'm basically annoyed by the gas mileage, so my question is- can I
> swap in an engine (or engine/tranny combo) that will give me at least
> the same performance (torque, power) and also has mpg in the 19-24 mpg
> range?
>
> Sure its a lot to ask, but if its possible I'd like to do it and
> figure it would be a fun project.
>
> thanks.

 

munchiechee did pass the time by typing:
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.

What you would spend on doing this would be much much much much much
more than what you would save on fuel. As Hesco says, "Speed costs
money, how fast do you want to go?"

Your 4.0 should be getting better than that. Let's start off with
the basics.

Plugs, Wires, Rotor, Cap

Clean the IAP http://members.***.net/wilsond/tb/tb.html

If the plugs show rich (excess carbon) then you should replace
the O2 sensor. Yes, it can set a code but the O2 sensor will drift
off long before any codes get set.

Depending on how long you have ran the cat might need replacement.

You should also check your exhaust header for cracks. The 4.0 header
is notorious for this. You know it's cracked when the engine sounds
like a diesel or you start getting what sounds like lifter noise.

Switch out to full synthetic if you haven't already, that's good for
a teeny improvement.

But by and far the best way to reduce fuel use is to take it slow and
easy. The goal on the highway is to not have to use the brakes. And
try not to beat folks to a red light. :) I tried driving like that for
a couple of tanks and it made a 4mpg difference in my city driving.
(then again my ZJ can gulp fuel)

--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

 

munchiechee did pass the time by typing:
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.

What you would spend on doing this would be much much much much much
more than what you would save on fuel. As Hesco says, "Speed costs
money, how fast do you want to go?"

Your 4.0 should be getting better than that. Let's start off with
the basics.

Plugs, Wires, Rotor, Cap

Clean the IAP http://members.***.net/wilsond/tb/tb.html

If the plugs show rich (excess carbon) then you should replace
the O2 sensor. Yes, it can set a code but the O2 sensor will drift
off long before any codes get set.

Depending on how long you have ran the cat might need replacement.

You should also check your exhaust header for cracks. The 4.0 header
is notorious for this. You know it's cracked when the engine sounds
like a diesel or you start getting what sounds like lifter noise.

Switch out to full synthetic if you haven't already, that's good for
a teeny improvement.

But by and far the best way to reduce fuel use is to take it slow and
easy. The goal on the highway is to not have to use the brakes. And
try not to beat folks to a red light. :) I tried driving like that for
a couple of tanks and it made a 4mpg difference in my city driving.
(then again my ZJ can gulp fuel)

--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

 

munchiechee did pass the time by typing:
> I have a 97 TJ 4.0/manual thats been great on road and off - the only
> consistent problem I have with the Jeep is the MPGs, way less than
> advertised, I'm averaging 12-14 in city and about 16 on freeway.
>
> I've checked everything out possible, and even taken it to the
> stealer; either I have a very heavy foot or I just have a thirsty
> jeep.

What you would spend on doing this would be much much much much much
more than what you would save on fuel. As Hesco says, "Speed costs
money, how fast do you want to go?"

Your 4.0 should be getting better than that. Let's start off with
the basics.

Plugs, Wires, Rotor, Cap

Clean the IAP http://members.***.net/wilsond/tb/tb.html

If the plugs show rich (excess carbon) then you should replace
the O2 sensor. Yes, it can set a code but the O2 sensor will drift
off long before any codes get set.

Depending on how long you have ran the cat might need replacement.

You should also check your exhaust header for cracks. The 4.0 header
is notorious for this. You know it's cracked when the engine sounds
like a diesel or you start getting what sounds like lifter noise.

Switch out to full synthetic if you haven't already, that's good for
a teeny improvement.

But by and far the best way to reduce fuel use is to take it slow and
easy. The goal on the highway is to not have to use the brakes. And
try not to beat folks to a red light. :) I tried driving like that for
a couple of tanks and it made a 4mpg difference in my city driving.
(then again my ZJ can gulp fuel)

--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!