Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Engine Performance/Intakes/Exhausts

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 11-28-2012, 10:17 AM
Tussle's Avatar
Member
My Jeep: 2013 5.7L WK2
 
Join Date: Oct 2012
Posts: 60
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 21984
Tussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond repute
Something I noticed about gas mileage - READ THIS!

So I have a 2013 Altitude with the 5.7. I put larger or taller tires on it, and I expected my gas mileage to drop or at least appear as it did. So for two weeks now I have been getting gas mileage that ranges from a high of 14.2 to a low (yesterday) of 13 on the way home. All during normal driving, same route to and from work, same traffic and whatnot, so the average, should be a pretty good or accurate one. This morning, I started the car, warmed it up, reset the mileage guage, turned on the tow haul mode, and drove to work. 85% highway, or at least 50+ up to 70 on the way to work. Couple of stop lights and a stretch at 45, and by the time I went the 18 miles to work, my gas mileage had gone from 13MPG with the tow haul off in normal mode with the MDS functioning, to 15.9MPG and climbing with the tow haul mode on!!! Read that again, I turned the tow haul mode on, and in 18 miles, my gas mileage increased by almost 3MPG! To me this makes zero sense! Is there any way to set the car so the tow haul mode is on all the time, or do I have to poke the button every time I get in the car if I want the better mileage, and the quicker snappier performance?
__________________

__________________
Reply With Quote
  #2  
Old 11-28-2012, 10:21 AM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,419
Thanks: 55
Thanked 133 Times in 115 Posts
Rep Power: 542699
robpp has disabled reputation
Re: Something I noticed about gas milage - READ THIS!

if you FOOL the computer with bigger tires....it causes weird calculations.

Do your test with a pen and a paper and report back/
__________________

__________________
Reply With Quote
  #3  
Old 11-28-2012, 10:35 AM
Tussle's Avatar
Member
My Jeep: 2013 5.7L WK2
 
Join Date: Oct 2012
Posts: 60
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 21984
Tussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond repute
Re: Something I noticed about gas milage - READ THIS!

Not weird, the calculations are the same as they were before, only slightly off from the stock tire dimension. There is nothing wrong with the computer, I just think the different shift points in the tow haul mode, are actually better or more efficient for the cars gas mileage! Or at least better for the cars gas mileage with the taller tires on. I was just wondering if anybody else had tried it to see if it helped them out any? I like the responsiveness of the tow haul mode, and with it getting way better gas mileage (I will drive it this way for a while to confirm) I don't see me driving in regular mode unless I am on the freeway doing 75+.
__________________
Reply With Quote
  #4  
Old 11-28-2012, 11:06 AM
Senior Member
My Jeep: 2011 3.6L WK2
 
Join Date: Dec 2011
Location: Olathe, KS
Posts: 1,003
Thanks: 0
Thanked 17 Times in 17 Posts
Rep Power: 3738
kkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond reputekkreit01 has a reputation beyond repute
Re: Something I noticed about gas milage - READ THIS!

Means nothing unless all conditions are identical throughout the test. Average for a month with button on/off, and the report back. Make sure to always use the same pump, same gas, drive the same route, same style, etc. There are far too many variables when comparing MPG. Wind alone makes a huge difference, and we cannot control that.
__________________
2014 Durango Limited AWD in Granite: Premium Package, 2nd Row Captain Chairs, 2nd row Console.
Reply With Quote
  #5  
Old 11-28-2012, 01:11 PM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,419
Thanks: 55
Thanked 133 Times in 115 Posts
Rep Power: 542699
robpp has disabled reputation
Re: Something I noticed about gas milage - READ THIS!

show me how much TALLEr the tires are...use a tire calc and post the diff.

also, the EVIC is cumulative gas milage. it doesnt reset every time you filll up.

use the mileage, factor in the % of taller tire, then do it for 3 months and let us know your findings/

even a .2 or .3 % in rolling size will impact your mileage, as well as all the factors listed above/
__________________
Reply With Quote
  #6  
Old 11-28-2012, 01:26 PM
Tussle's Avatar
Member
My Jeep: 2013 5.7L WK2
 
Join Date: Oct 2012
Posts: 60
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 21984
Tussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond reputeTussle has a reputation beyond repute
Re: Something I noticed about gas milage - READ THIS!

It resets, every time you reset it in the trip computer which I do every time I fill up. I don't think you guys are getting the bigger picture. With the taller tires on there, I am getting 13. With the taller tires and tow haul mode on, I got 15.9 on the way into town. Real world, normal everyday driving, like always. Makes no difference how much taller the tires are, as they are the same during both mileage averages. I know a real comparison, would be in an air tight chamber, same temp, no wind, and burn 5 tanks of gas with and without tow haul on to eliminate any possible change in factors. But be real, every day driving is what you do, so none of that makes any difference. Tank to tank real world is the only thing that has any relevance. My point by making this post, and I just drove another 8 miles, and it's still 15.9, is that the car gets better gas mileage or seems to "so far" with the tow haul on. You people seem to squeeze and suck the life and fun out of everything. In any case, I am done posting about it.
__________________
Reply With Quote
  #7  
Old 11-28-2012, 03:21 PM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,419
Thanks: 55
Thanked 133 Times in 115 Posts
Rep Power: 542699
robpp has disabled reputation
Re: Something I noticed about gas mileage - READ THIS!

awww yourbutt hurt...LOL

sowwy /
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas mileage Redealmaker Grand Cherokee SRT - WK2 10 05-24-2012 09:27 AM
BS Gas Mileage 2005 WK Troubleshooting/Problems 19 01-08-2012 11:24 PM
gas mileage? 4.0 what can i do? boosted88coupe Engine Performance/Intake/Exhaust 39 12-21-2011 12:40 AM
V6 gas mileage bluetrude Engine Performance/Intakes/Exhausts 60 09-06-2011 10:21 AM
4.7L gas mileage... Bigdiesel74 Performance Modifications 15 10-22-2009 09:58 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 01:28 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by Chrysler Group LLC.