Observation on gas mileage - JeepForum.com
LinkBack Thread Tools
post #1 of 7 Old 03-13-2012, 10:26 PM Thread Starter
Registered User
2000 XJ Cherokee 
Join Date: Apr 2010
Location: MI
Posts: 771
Observation on gas mileage

This is not a typical gas mileage post, I am not complaining or asking questions as to why my mileage is poor. I know I drive a jeep.

Ok, on with the thread.

My Xj gets 17-21mpg all summer depending on my driving conditions. This is good enough for me. When winter hits I see 12-15mpg almost instantly and 9-11mpg when I use four wheel drive a lot. My driving is the same year round. Obviously 12-15mpg is pretty bad for an XJ that has 235's and isn't lifted.

Now I understand fuel economy will suffer in winter. The air is more dense, it takes a little longer for the engine to reach operating temp, the oil takes longer to warm up, some let their cars "warm-up" before driving, four wheel drive, and there is a supposed winter blend of gasoline.

So factor all of that in and you'd expect to see some decrease in gas mileage, no problem. Kind of sucks, but there isn't much you can do.

However, this year in southern MI, we've had an unusual winter. It has been in the 40's for the majority of the winter, we've had very little snow, and more recently it's been in the 50's and 60's.

So almost all of the reasons normally given for poor mileage during winter haven't applied to this winter, yet my mileage is still 12-15mpg. The winter blend is the only thing left that I could even think of to explain my horrible mileage.

Two days ago I made a 120 mile round trip to the Casino. I went 65mph and 55mph the whole way. It should've been an easy 19mpg at the very least as it was in the high 50's all day and the driving was perfect. I got 16mpg. This type of driving is when my XJ see's its best mileage.

As soon as I got back, I topped my tank off again. I noticed the station had just been re-filled as the tanker was just pulling away. I topped the tank off and have been driving my normal routine(55mph, 45mph and half of the driving was 35 or less) for the past two days. I filled it up today and found that I got 17mpg. It was in the 50's again and the weather was perfect while driving. This is when my Xj see's its average/low mileage.

This gives me reason to beleive that the winter blend of gaslone should be given much credit in the loss of our fuel economey. I think the station just received the summer blend of gasoline as winter is almost over here and that is why I got better mileage. Now I need to read about why some vehicles see this loss in gas mileage, and if there is a way to help.

Hopefully some of you that DD your XJ's find this interesting, when 1/4 of your pay goes into the tank, I can't help but try to find answers.

DerMeister is offline  
Sponsored Links
post #2 of 7 Old 03-14-2012, 03:28 AM
Registered User
1993 XJ Cherokee 
Join Date: Sep 2010
Location: Northglenn
Posts: 190
I 100% agree with the winter blend of gasoline making a difference; I see it myself as well. During the peak of summer when I run the A/C and once the gasoline changes in the winter my MPG drops dramatically. During the fall and spring I easily get 4-5mpg better than the harsher seasons on simple commute driving.

scavok is offline  
post #3 of 7 Old 03-14-2012, 08:14 AM
Registered User
1993 XJ Cherokee 
Join Date: Nov 2007
Location: Tyler
Posts: 42
The gas can make a huge difference on MPG. Back when they started using the 10% ethanol gas my car (2001 MR2) went from about 33mpg to 27-29 in one tank of gas and when I could find the "normal" gas it would be right back to 33.

I have no clue what winter blend gas is as I live in Texas and we don't get cold weather, but that could make a difference.
toaster is offline  
post #4 of 7 Old 03-14-2012, 09:26 AM
Registered User
2001 XJ Cherokee 
Join Date: Sep 2010
Location: Finleyville
Posts: 3,334
If you could get around the regulations, and actually open an ethanol free gas station, in almost any area, you would make a mint.


Both my motorcycles run great on straight up gas, when I can find it (usually out in rural areas) and drop easy 12% in mileage on E10.

Im the guy who makes new gauges, check out our gallery at Teamadw.com
Azzy is offline  
post #5 of 7 Old 03-14-2012, 10:13 AM
Registered User
1996 XJ Cherokee 
Join Date: Sep 2010
Location: Lynden
Posts: 298
I run 215/75/15 on my XJ and checked the mileage on a run up to Canada with a 5 minute wait going up and 20 minute wait coming back into the USA at the border and averaged 50 MPH and got 18.7 mpg. I only use Chevron regular.

1996 RHD XJ
Ratrod is offline  
post #6 of 7 Old 03-15-2012, 06:29 PM
Registered User
2001 XJ Cherokee 
Join Date: May 2011
Location: pittstown
Posts: 769
I just drove 257 miles from VT to NJ with avergae speed at 80 and about 50 degrees out. I got to NJ and checked my mileage and got 17.5 mpg. I was pretty happy with that. Stock 3.55 on 30s and about 150lbs of gear and myself.

2015 Ford F350 crew cab, gasser
2001 Cherokee sport "AGENT ORANGE"
1991 Ford 7.3L IDI- FOR SALE
IDIdiesel is offline  
post #7 of 7 Old 03-16-2012, 09:15 AM
jeepkid03's Avatar
2000 XJ Cherokee 
Join Date: Sep 2008
Location: Storrs
Posts: 6,247
The winter blend gasoline plays a big part. Some of the stations around me even have as much as 15% ethanol in the gas. With the combination of the winter blend and 15% ethanol I'm actually happy to get 14-15 mpg in a lifted jeep.

Honestly, MPG doesn't bother me much anymore. My Jeep has been reliable, and is completely paid for. I have a short commute, and it would be foolish to buy a newer car that gets better mpg in my case. The money I'd save in gas would be outweighed by the insurance and car payments. Plus it wouldn't be 4WD most likely in order to get better gas mileage.

Even some of the newer 4x4s get around 22-24 mpg highway for the smaller ones. That isn't all that good considering my 12 year old Cherokee with 120k miles and the aerodynamics of a brick wall can get 19-20 mpg if I drive 60 mph on the highway.


My 0331 Head Swap How-To Thread:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Build Thread:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
jeepkid03 is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


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.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Help with gas mileage Joshharris98xj XJ Cherokee Technical Forum 46 05-05-2011 04:28 AM
Interesting CPS Observation CDNXJ XJ Cherokee Technical Forum 2 04-23-2008 02:56 PM
I Need Better Gas Mileage!!! 87blkcherokee XJ Cherokee Technical Forum 19 01-18-2008 07:52 PM
4wd Question/Observation Dirty Pile XJ Cherokee Technical Forum 5 01-18-2006 06:28 PM
Front axle shaft removal/bearing questions/observation IndyXJ XJ Cherokee Technical Forum 3 02-12-2005 10:08 PM

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
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome