Hemi Gas Mileage calculation - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK > Engine Performance/Intake/Exhaust

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 12-19-2014, 02:47 PM
Member
 
Join Date: Dec 2010
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2256
TheNoachSHO is on a distinguished road
Hemi Gas Mileage calculation

So I got a new job and am driving my 05 Hemi around much more than ever before. Little background, bought it 5 years ago with 56k on it and only now have 80k. Never drove it more than 50 miles from home and used it to mostly tow my smallish boat.

I've always got about 13 MPG and maybe i'd see 15 a few times if I was really lucky (not towing of course).

so I took it on it's first long trip and had something funny happen. About halfway into a two hour ride I was getting about 14.7 to 15MPG's. Then I felt a slight stutter and my MPG's shot up to 16.5 - 16.8. On my way home I got 14.2 for most of the trip then suddenly about 3/4 of the way back it shot up again, only this time I actually saw 17 MPG!!!

Clearly something is going on. I've always used Mobil 1, 5-20 and a Mopar filter every 5k. I'm thinking that maybe the MDS solenoid was gunked up and finally free'd???

Does anyone know how the EVIC calculates MPG's? Has anyone experienced this before or have theroies about it. I'm just trying to figure out what the cause was so I can learn how to drive it at maximum MPG.

Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 12-19-2014, 03:47 PM
Sleeps's Avatar
Senior Member
My Jeep: 2005 5.7L WK
 
Join Date: Oct 2013
Posts: 1,111
Thanks: 0
Thanked 71 Times in 64 Posts
Rep Power: 582183
Sleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond repute
Quote:
Originally Posted by TheNoachSHO View Post
So I got a new job and am driving my 05 Hemi around much more than ever before. Little background, bought it 5 years ago with 56k on it and only now have 80k. Never drove it more than 50 miles from home and used it to mostly tow my smallish boat.

I've always got about 13 MPG and maybe i'd see 15 a few times if I was really lucky (not towing of course).

so I took it on it's first long trip and had something funny happen. About halfway into a two hour ride I was getting about 14.7 to 15MPG's. Then I felt a slight stutter and my MPG's shot up to 16.5 - 16.8. On my way home I got 14.2 for most of the trip then suddenly about 3/4 of the way back it shot up again, only this time I actually saw 17 MPG!!!

Clearly something is going on. I've always used Mobil 1, 5-20 and a Mopar filter every 5k. I'm thinking that maybe the MDS solenoid was gunked up and finally free'd???

Does anyone know how the EVIC calculates MPG's? Has anyone experienced this before or have theroies about it. I'm just trying to figure out what the cause was so I can learn how to drive it at maximum MPG.
Avg of 300 miles for the evic. My 05 gets about 17 to 18 at 73ish.. drop down to 70 or a little below its at about 19. Given i have a air intake and a modded exhaust but dont have a proper tune to get the full advantage. Can also reset your evic when you get on the highway to really see just highway mileage. The city and idle kill the avg fuel on the hemis.

Look at your spark plugs, pcv valve and map sensor. Get some seafoam cans to further clean out your engine and pipes. The seafoam will put out alot of smoke but it really does help the engine breath.
Reply With Quote
  #3  
Old 12-19-2014, 04:17 PM
Premium Member
My Jeep: 2014 5.7L WK2
 
Join Date: May 2013
Location: Colorado
Posts: 3,997
Thanks: 73
Thanked 277 Times in 244 Posts
Rep Power: 46293
lstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond reputelstowell has a reputation beyond repute
Re: Hemi Gas Mileage calculation

Quote:
Originally Posted by TheNoachSHO View Post
So I got a new job and am driving my 05 Hemi around much more than ever before. Little background, bought it 5 years ago with 56k on it and only now have 80k. Never drove it more than 50 miles from home and used it to mostly tow my smallish boat.

I've always got about 13 MPG and maybe i'd see 15 a few times if I was really lucky (not towing of course).

so I took it on it's first long trip and had something funny happen. About halfway into a two hour ride I was getting about 14.7 to 15MPG's. Then I felt a slight stutter and my MPG's shot up to 16.5 - 16.8. On my way home I got 14.2 for most of the trip then suddenly about 3/4 of the way back it shot up again, only this time I actually saw 17 MPG!!!

Clearly something is going on. I've always used Mobil 1, 5-20 and a Mopar filter every 5k. I'm thinking that maybe the MDS solenoid was gunked up and finally free'd???

Does anyone know how the EVIC calculates MPG's? Has anyone experienced this before or have theroies about it. I'm just trying to figure out what the cause was so I can learn how to drive it at maximum MPG.
It could be a good guess that the MDS is misbehaving--it should be almost undetectable when it switches from 8 to 4 and back.

I dunno if a Seafoam flush followed by a new refill of Mobil1 would help degunk it--I wouldn't try it until someone with your same year engine chimes in.

As for how to get the max mileage from the Hemi.... forget it is a Hemi until you really need or want a Hemi. As in, pretend there is a bottle of nitroglycerin between your foot and the gas pedal. Keeping a steady speed as opposed to moving speed up and down and up and down helps. Easing off just a small bit on uphills can help, depending on the hill.

Oddly enough, taking it too easy from a stop can hurt, as the quicker you can get up into the higher gears the better your mileage will be UNLESS in the process of getting there you hit the gas so hard that it enriches the fuel mix. Somewhere just a bit between half and 3/4 throttle tends to work best for most engines.

'Course the real method is to get a 14 or newer with the 8 speed that can put you in the low 20's at cruise--but even those suck gas in slow traffic. Thats why diesels exist.
Reply With Quote
  #4  
Old 12-19-2014, 06:32 PM
Sleeps's Avatar
Senior Member
My Jeep: 2005 5.7L WK
 
Join Date: Oct 2013
Posts: 1,111
Thanks: 0
Thanked 71 Times in 64 Posts
Rep Power: 582183
Sleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond reputeSleeps has a reputation beyond repute
Quote:
Originally Posted by lstowell View Post
It could be a good guess that the MDS is misbehaving--it should be almost undetectable when it switches from 8 to 4 and back.

I dunno if a Seafoam flush followed by a new refill of Mobil1 would help degunk it--I wouldn't try it until someone with your same year engine chimes in.

As for how to get the max mileage from the Hemi.... forget it is a Hemi until you really need or want a Hemi. As in, pretend there is a bottle of nitroglycerin between your foot and the gas pedal. Keeping a steady speed as opposed to moving speed up and down and up and down helps. Easing off just a small bit on uphills can help, depending on the hill.

Oddly enough, taking it too easy from a stop can hurt, as the quicker you can get up into the higher gears the better your mileage will be UNLESS in the process of getting there you hit the gas so hard that it enriches the fuel mix. Somewhere just a bit between half and 3/4 throttle tends to work best for most engines.

'Course the real method is to get a 14 or newer with the 8 speed that can put you in the low 20's at cruise--but even those suck gas in slow traffic. Thats why diesels exist.
Seafoam helped me with my 05 hemi.. thats why i told him to do it.
Reply With Quote
Reply

Tags
hemi

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
Another Hemi Gas-Mileage Thread Jofus311 Engine Performance/Intake/Exhaust 29 12-04-2014 12:06 AM
Can I mix High mileage Full synthetic with regular High Mileage? sergioad89 Engine Performance/Intake/Exhaust 8 06-30-2012 07:38 AM
Hemi Gas Mileage johnsavarese Engine Performance/Intakes/Exhausts 35 12-18-2011 07:25 AM
Hemi Gas Mileage? kaflyboy Grand Cherokee - WK2 - 50 08-23-2011 04:33 PM
4.7L gas mileage... Bigdiesel74 Performance Modifications 15 10-22-2009 10:58 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 04:26 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.