Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum > Gas mileage problems

Join Wrangler Forum Today


Thread: Gas mileage problems Reply to Thread
Title:
  
Message:
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-21-2008 08:59 PM
Triple88a I just ordered a 29 tooth gear from ebay. The seller also says he has 27 tooth gear. I mentioned to him that some one i know "might" be interested in it. I'll see what he says and i'll let you guys know.

04-21-2008 08:41 PM
4point
Quote:
Originally Posted by juspimpin View Post
ttt..

condensation, anyone, anyone?
Yes, just as you described. But I believe it has to do with humidity in the air.
04-21-2008 08:32 PM
juspimpin ttt..

condensation, anyone, anyone?
04-20-2008 09:50 PM
juspimpin
Quote:
Originally Posted by Triple88a View Post
very funny dude.. i am getting MORE miles than my odo says. My oddo says 115!!! it turns slower so it reads slower therefore 115x1.17 as thats the ratio of the right speedo gear i need vs the one i have...

by that you're saying that after i install my 35s my axles are spinning faster even though i have a bigger radius tires? stock tires my speedo would read let say 60 mph and now when my speedo reads 60 i'm going slower? uuhhh no

impossible is a big word. Try it your self some time.. cruize around town on 2-3 gear and see what mpg you get and then cruize on 5th gear and see what mpg u get.
I just went from 33s to 35s and I get better mileage now. I always get gas around 200 miles and about 16 gallons. Last 3 tanks I made it past 210 and still put in about 16 gallons. That may not seem like much but without fixing speedo, i am actually driving more than that so the improvement is that much bigger. MPG went from around 15 to almost 17 on each of last tanks...impressive....and it looks so much better...

my question for all is on condensation. I get water from exhaust dripping from tailpipe and from right in front of muffler through transfer case skid...I think it is more than it should be while idling...I let it idle for about 4 minutes when I ran in the house and had 2 puddles of about 6 inches...whats with that?
04-20-2008 07:42 PM
4.0l sahara
Quote:
Originally Posted by nregas1 View Post
What kind of age/miles is common for the o2 sensors to need replacing? I'm a bit curious about this b/c I've started to gradually loose some mpg. But the rig only has 50K and is a 2004. Seem to have lost a little power too. Neither symptom is drastic, but power and mpg just doesn't seem to be what it was 6 months ago. And in that same time period the exhaust tip has developed a soot ring at the opening. Dealer just says, "if you drank fuel and then set it on fire in your belly, I bet your exhaust pipe would be black too". Gee thank a-hole. BUT, like the post earlier, I'm not getting any codes.
Just replace the upstream o2 senser as this is what controlles the air/fuel. But at 50k I could see them needing to be replaced. I need to pick up a new one as i have 100k on the original one.
04-20-2008 07:35 PM
richp
Quote:
Originally Posted by nregas1 View Post
What kind of age/miles is common for the o2 sensors to need replacing? I'm a bit curious about this b/c I've started to gradually loose some mpg. But the rig only has 50K and is a 2004. Seem to have lost a little power too. Neither symptom is drastic, but power and mpg just doesn't seem to be what it was 6 months ago. And in that same time period the exhaust tip has developed a soot ring at the opening. Dealer just says, "if you drank fuel and then set it on fire in your belly, I bet your exhaust pipe would be black too". Gee thank a-hole. BUT, like the post earlier, I'm not getting any codes.

Unless you are doing almost exclusively interstate hiway driving you really need to replace your plugs. My 98 XJ's plugs used to last about 80,000mi which for me was almost 2 years, when I would pull them the gap would be between .50 and .55 thousands vs the .35 they are supposed to be.
04-20-2008 12:07 PM
Triple88a
Quote:
Originally Posted by Smeghead View Post
PLus in England your about 1000% more likely to have some bastard put a knife through it just for fun, thats why i didnt have a soft top while I lived there
Same here in chicago. People like that deserve to be shot and if moving then shot again!!!
04-20-2008 12:05 PM
4point
Quote:
Originally Posted by Gerald View Post
Have just run through a tank of gas and got 280 miles, with a mix of city and highway cruising at 70. Much better since the new O2 sensor. Thanks
I was happy with mine on Friday, I left Las Vegas, NV and traveled to Fresno, CA a little over 400mi. and averaged 17.4 mpg.
04-20-2008 11:42 AM
Smeghead
Quote:
Originally Posted by Gerald View Post
Not too many here, mostly Cherokees. I think there are only about 8000 wranglers in the whole country. Parts are always damn expensive too and I work for one of the only wholesalers that even stock the parts. I find it cheeper to order direct from the states. For example a replacement soft top fabric is sold here for £575 ($1100) it's only $300 in the US!
PLus in England your about 1000% more likely to have some bastard put a knife through it just for fun, thats why i didnt have a soft top while I lived there
04-20-2008 11:37 AM
nregas1 What kind of age/miles is common for the o2 sensors to need replacing? I'm a bit curious about this b/c I've started to gradually loose some mpg. But the rig only has 50K and is a 2004. Seem to have lost a little power too. Neither symptom is drastic, but power and mpg just doesn't seem to be what it was 6 months ago. And in that same time period the exhaust tip has developed a soot ring at the opening. Dealer just says, "if you drank fuel and then set it on fire in your belly, I bet your exhaust pipe would be black too". Gee thank a-hole. BUT, like the post earlier, I'm not getting any codes.
04-20-2008 08:59 AM
Gerald Have just run through a tank of gas and got 280 miles, with a mix of city and highway cruising at 70. Much better since the new O2 sensor. Thanks
04-07-2008 12:00 AM
Triple88a
Quote:
Originally Posted by spanky View Post
haha youre getting LESS miles than your odo says. which kinda seems IMPOSSIBLE that youre getting BETTER gas mileage after your install of 35's. check your math again.
very funny dude.. i am getting MORE miles than my odo says. My oddo says 115!!! it turns slower so it reads slower therefore 115x1.17 as thats the ratio of the right speedo gear i need vs the one i have...

by that you're saying that after i install my 35s my axles are spinning faster even though i have a bigger radius tires? stock tires my speedo would read let say 60 mph and now when my speedo reads 60 i'm going slower? uuhhh no

impossible is a big word. Try it your self some time.. cruize around town on 2-3 gear and see what mpg you get and then cruize on 5th gear and see what mpg u get.
04-06-2008 11:12 PM
spanky
Quote:
Originally Posted by Triple88a View Post
how much gas does he put in? i get ~240 a tank before i added my 35s and now believe it or not i think i might be getting better. Currently i have a little more than a half a tank of gas left and my odo measures 115

i still have not corrected my speedo gear so thats 115x1.17=135 miles

I still need to run one tank completely as something always happens lol. My first tank after the 35s i took a trip so it was almost all highway. The tank after that my battery died so my odo reset, this is the 3rd tank of gas i think.
haha youre getting LESS miles than your odo says. which kinda seems IMPOSSIBLE that youre getting BETTER gas mileage after your install of 35's. check your math again.
04-06-2008 05:03 PM
Triple88a
Quote:
Originally Posted by rockstar4christ View Post
When my bro first got his Tj he got 175 to a tank. Now he gets 215! with our special additives. Like 18mpg I guess.
how much gas does he put in? i get ~240 a tank before i added my 35s and now believe it or not i think i might be getting better. Currently i have a little more than a half a tank of gas left and my odo measures 115

i still have not corrected my speedo gear so thats 115x1.17=135 miles

I still need to run one tank completely as something always happens lol. My first tank after the 35s i took a trip so it was almost all highway. The tank after that my battery died so my odo reset, this is the 3rd tank of gas i think.
04-06-2008 04:49 PM
rockstar4christ When my bro first got his Tj he got 175 to a tank. Now he gets 215! with our special additives. Like 18mpg I guess.
04-06-2008 02:15 PM
UNLIMITLESS O2s and a "Seafoam" cleaning may help. At 5 mpg replacing both O2s would still be less than a couple tanks of fuel.
04-06-2008 05:43 AM
Gerald Just fitted a new O2 sensor (what a simple job!!) and will monitor the milage. There was no fault showing on the diagnostic system (dealer level) but the lamda readings were not changing as quick as one would expect. Hope this helps, next thing is gonna be a map sensor (ouch) Hope your problem is easier to find than mine!!
04-05-2008 10:56 AM
richp
Quote:
Originally Posted by soupy1957 View Post
25.4 mpg in my 2008 Wrangler X (reading right off the gauge on the dash)!

-Soupy1957
Is that with the 4 or the 6 cylinder and have they improved it that much ?
04-05-2008 10:41 AM
Triple88a could some one hit soupy with a big book or something for coming here and bragging.
lol

As far as ur problem goes i believe its an O2 Sensor too...you can use a scanner and see what the ECU sees (as in data received from the sensors) I believe autozone will do it for free.
04-05-2008 09:02 AM
soupy1957 25.4 mpg in my 2008 Wrangler X (reading right off the gauge on the dash)!

-Soupy1957
04-05-2008 07:33 AM
richp O2 sensors can also get what my friend calls 'lazy' which will not throw a check engine light but will hurt mileage.
04-05-2008 12:18 AM
spanky
Quote:
Originally Posted by Jerry Bransford View Post
A sudden drop in fuel economy is often nothing more than the upstream (nearest to the exhaust header) 02 sensor has gone bad. When it goes bad, the air-fuel mixture turns full rich so the mpg immediately goes into the toilet. Older TJs have one upstream 02 sensor, newer TJs have two upstream 02 sensors. Being able to smell gasoline is often another symptom of this problem.

Another possible cause would be a clogged (bad) catalytic converter but my first thought is a bad 02 sensor. And they do go bad, they need periodic replacing.
would any of these O2 sensors you mentioned throw a CEL ?? My MPG has also gone to crap, but as of now, no CEL.
03-21-2008 10:09 AM
Jerry Bransford A sudden drop in fuel economy is often nothing more than the upstream (nearest to the exhaust header) 02 sensor has gone bad. When it goes bad, the air-fuel mixture turns full rich so the mpg immediately goes into the toilet. Older TJs have one upstream 02 sensor, newer TJs have two upstream 02 sensors. Being able to smell gasoline is often another symptom of this problem.

Another possible cause would be a clogged (bad) catalytic converter but my first thought is a bad 02 sensor. And they do go bad, they need periodic replacing.
03-21-2008 09:49 AM
richp The other biggie is the thermostat, if your jeeps engine does not reach 185F or above the ECU keeps the engine in cold loop which dumps twice the gas in. Our 97ZJ had a stuck open tstat that came out in pieces when I replaced it back in October. That ZJ was getting about 7mpg on the trip home from New Jersey to home in Pennsylvania.
03-21-2008 09:27 AM
Rawkon is there en engine light???? id say 02 sensor is the culprit. I have 33s a 3 speed auto, stock 3.73s and i just had a tank of 17 on the highway and 13 while wheeling
03-21-2008 05:31 AM
JCS05Rubi Most fuel system cleaners are similar, true, but there is a gentlemen on here (Jerry Bradsworth i believe?) that knows an old school way using water
03-20-2008 10:31 PM
branty Haha, as far as I know, there's no magic to which fuel system cleaner you use. I think they ultimately all do the same thing.

Your right, you cannot easily replace the fuel filter. As soon as I purchased my TJ I learned that you can only purchase it from the dealer and it comes pre assembled with attached lines. Not to mention what it takes to get to it.
03-20-2008 04:47 PM
JCS05Rubi One of the above posts is parially inaccurate. There is no replacable fuel filter on a wrangler, its a one piece fuel pump assembly inside the tank.

It sounds like your issue is an 02 sensor. Ive have that happen to a 4.0 before, with the same results.

After you figure out which 02 sensor went back, and fix it, you still may want to check your plug wires, air filter, and do a fuel system cleaner (the fuel system cleaning guru should chime in here soon) just for safe measure
03-20-2008 04:32 PM
Gerald Not too many here, mostly Cherokees. I think there are only about 8000 wranglers in the whole country. Parts are always damn expensive too and I work for one of the only wholesalers that even stock the parts. I find it cheeper to order direct from the states. For example a replacement soft top fabric is sold here for £575 ($1100) it's only $300 in the US!
03-20-2008 03:20 PM
juspimpin
Quote:
Originally Posted by Gerald View Post
mine's doing the same thing!!! has just done 30miles on 1/4 tank of fuel!!! At $2.20/litre in the UK that is tough
That is over $8 a gallon, and I only pay 3.15-3.20 now. Been to england, my Grandmother-in-law lives in manchester. Only paid 95p/liter then and that still sucked. Traffic accident on my birthday....My money does not go far over there. Never seen a jeep over there either.
This thread has more than 30 replies. Click here to review the whole thread.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -5. The time now is 10:39 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC