DougW

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!

Jerry Bransford

12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
mpg all-around driving with obviously a bit more on the highway if I keep my
speed down. The big issue is the Wrangler's barn door aerodynamics which
don't help with fuel economy. Even the Grand Cherokee with the same engine
will get better fuel economy due to it's vastly better aerodynamics.

The bottom line is that it's a Jeep Wrangler that is built for offroading,
it's not an econo-box or car that has more going for it so far as having
more potential for better economy. Once again... if you can't live with
that fuel economy, it's time to get something else to drive.... Jeeps aren't
for you.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/
"DougW" <post.replies@invalid.address> wrote in message
news:lH2Wc.57830$wo.52540@okepread06...
> 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!
>
>

Jerry Bransford

12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
mpg all-around driving with obviously a bit more on the highway if I keep my
speed down. The big issue is the Wrangler's barn door aerodynamics which
don't help with fuel economy. Even the Grand Cherokee with the same engine
will get better fuel economy due to it's vastly better aerodynamics.

The bottom line is that it's a Jeep Wrangler that is built for offroading,
it's not an econo-box or car that has more going for it so far as having
more potential for better economy. Once again... if you can't live with
that fuel economy, it's time to get something else to drive.... Jeeps aren't
for you.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/
"DougW" <post.replies@invalid.address> wrote in message
news:lH2Wc.57830$wo.52540@okepread06...
> 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!
>
>

Jerry Bransford

12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
mpg all-around driving with obviously a bit more on the highway if I keep my
speed down. The big issue is the Wrangler's barn door aerodynamics which
don't help with fuel economy. Even the Grand Cherokee with the same engine
will get better fuel economy due to it's vastly better aerodynamics.

The bottom line is that it's a Jeep Wrangler that is built for offroading,
it's not an econo-box or car that has more going for it so far as having
more potential for better economy. Once again... if you can't live with
that fuel economy, it's time to get something else to drive.... Jeeps aren't
for you.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/
"DougW" <post.replies@invalid.address> wrote in message
news:lH2Wc.57830$wo.52540@okepread06...
> 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!
>
>

Jerry Bransford

12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
mpg all-around driving with obviously a bit more on the highway if I keep my
speed down. The big issue is the Wrangler's barn door aerodynamics which
don't help with fuel economy. Even the Grand Cherokee with the same engine
will get better fuel economy due to it's vastly better aerodynamics.

The bottom line is that it's a Jeep Wrangler that is built for offroading,
it's not an econo-box or car that has more going for it so far as having
more potential for better economy. Once again... if you can't live with
that fuel economy, it's time to get something else to drive.... Jeeps aren't
for you.

Jerry
--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.***.net/jerrypb/
"DougW" <post.replies@invalid.address> wrote in message
news:lH2Wc.57830$wo.52540@okepread06...
> 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!
>
>

Lon

Jerry Bransford proclaimed:

> 12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
> neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
> mpg all-around driving with obviously a bit more on the highway if I keep my
> speed down. The big issue is the Wrangler's barn door aerodynamics which
> don't help with fuel economy. Even the Grand Cherokee with the same engine
> will get better fuel economy due to it's vastly better aerodynamics.

Even with the aerodynamics of a brick, 4-5 mpg seems a lot
of difference between the Wrangler and the ZJ. What kind of
rpm does the Wrangler need to turn to cruise at 70 mph? The
ZJ is loafing along at 2000 at highway cruise range and gets
20-21 at that speed.

Dunno how much improvement the OP would get by boosting the
compression ratio a tad. Would bet not enough to pay for the
modifications, but not everyone's priorities are the same.

Lon

Jerry Bransford proclaimed:

> 12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
> neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
> mpg all-around driving with obviously a bit more on the highway if I keep my
> speed down. The big issue is the Wrangler's barn door aerodynamics which
> don't help with fuel economy. Even the Grand Cherokee with the same engine
> will get better fuel economy due to it's vastly better aerodynamics.

Even with the aerodynamics of a brick, 4-5 mpg seems a lot
of difference between the Wrangler and the ZJ. What kind of
rpm does the Wrangler need to turn to cruise at 70 mph? The
ZJ is loafing along at 2000 at highway cruise range and gets
20-21 at that speed.

Dunno how much improvement the OP would get by boosting the
compression ratio a tad. Would bet not enough to pay for the
modifications, but not everyone's priorities are the same.

Lon

Jerry Bransford proclaimed:

> 12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
> neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
> mpg all-around driving with obviously a bit more on the highway if I keep my
> speed down. The big issue is the Wrangler's barn door aerodynamics which
> don't help with fuel economy. Even the Grand Cherokee with the same engine
> will get better fuel economy due to it's vastly better aerodynamics.

Even with the aerodynamics of a brick, 4-5 mpg seems a lot
of difference between the Wrangler and the ZJ. What kind of
rpm does the Wrangler need to turn to cruise at 70 mph? The
ZJ is loafing along at 2000 at highway cruise range and gets
20-21 at that speed.

Dunno how much improvement the OP would get by boosting the
compression ratio a tad. Would bet not enough to pay for the
modifications, but not everyone's priorities are the same.

Lon

Jerry Bransford proclaimed:

> 12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
> neither low nor high. My own Wrangler, built, gets right around 12.5 to 13
> mpg all-around driving with obviously a bit more on the highway if I keep my
> speed down. The big issue is the Wrangler's barn door aerodynamics which
> don't help with fuel economy. Even the Grand Cherokee with the same engine
> will get better fuel economy due to it's vastly better aerodynamics.

Even with the aerodynamics of a brick, 4-5 mpg seems a lot
of difference between the Wrangler and the ZJ. What kind of
rpm does the Wrangler need to turn to cruise at 70 mph? The
ZJ is loafing along at 2000 at highway cruise range and gets
20-21 at that speed.

Dunno how much improvement the OP would get by boosting the
compression ratio a tad. Would bet not enough to pay for the
modifications, but not everyone's priorities are the same.

Andy

I agree with Jerry. I have a built TJ (35" tires) and I get the same as he
mentioned. I am between 2000 and 2800 RPMs' on the highway to keep the
engine in it's sweet spot. I run 488 gears. The slower I go on the highway
relates to better mileage. I'm planning a trip cross country and I've
factored in the fact that I will have to leave a day earlier. Go slower.

Andy
2001 TJ

"Jerry Bransford" <jerrypb@***.net> wrote in message
news:8S2Wc.125987$sh.71214@fed1read06...
> 12-14 around town and 16 on the freeway is NORMAL for a Wrangler. It's
> neither low nor high. My own Wrangler, built, gets right around 12.5 to
13
> mpg all-around driving with obviously a bit more on the highway if I keep
my
> speed down. The big issue is the Wrangler's barn door aerodynamics which
> don't help with fuel economy. Even the Grand Cherokee with the same
engine
> will get better fuel economy due to it's vastly better aerodynamics.
>
> The bottom line is that it's a Jeep Wrangler that is built for offroading,
> it's not an econo-box or car that has more going for it so far as having
> more potential for better economy. Once again... if you can't live with
> that fuel economy, it's time to get something else to drive.... Jeeps
aren't
> for you.
>
> Jerry
> --
> Jerry Bransford
> PP-ASEL N6TAY
> See the Geezer Jeep at
> http://members.***.net/jerrypb/
> "DougW" <post.replies@invalid.address> wrote in message
> news:lH2Wc.57830$wo.52540@okepread06...
> > 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!
> >
> >
>
>