Poor Highway mileage - Ford Powerstroke Diesel Forum
6.0L Performance Parts Discussion What has or has not worked for you?

Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-05-2008, 12:58 PM
Member
 

Join Date: Jun 2008
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Poor Highway mileage

I've been running Innovative Aggressive Street tune for a few months now and average 17.5mpg city driving (21 stoplights in a 24 mile commute). The best tank I've seen in the city with a VERY LIGHT FOOT was 19.8mpg. 17.5mpg average is up 1.5mpg from my complete stock city driving average.

I averaged 11mpg with the aggressive Tow tune taking the camper back and forth to the beach (mostly flat). That is 2mpg less than my stock average when towing the camper.

Yesterday I needed to drive back and forth to Richmond VA from Raleigh NC for business. It was about 360 mile round trip. It was all highway at approx 70mph. I had 3 passengers and our average weight was probably 200 so I had about 800lb load in the cab

I expected to get >20mpg on the highway mile round trip but only got 17mpg. I filled just before and refilled immediately after the trip and had filled up to the neck both times.

I'm disappointed with the mileage. I used to get 18.5mpg on the stock tune on unloaded highway trips.

So my average city driving is 1.5mpg better than stock but 1.5mpg worse than stock on the highway.

Any ideas?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 09-05-2008, 01:04 PM
Member
 

Join Date: Aug 2008
Posts: 77
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Do you ever run a fuel treatment or cetane boost?
Reply With Quote Quick reply to this message
  #3  
Old 09-05-2008, 01:04 PM
Member
 

Join Date: Jun 2008
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Yes I run the stuff in the silver bottle... Power Service I think it's called
Reply With Quote Quick reply to this message
  #4  
Old 09-05-2008, 01:09 PM
Member
 

Join Date: Aug 2008
Posts: 77
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I been using amsoil fuel treatment and cetane boost and I can tell a difference in milleage when I dont use it thought that might be a factor in your situation.
Reply With Quote Quick reply to this message
  #5  
Old 09-05-2008, 03:22 PM
Compression Ignition Addict
 

Join Date: Jul 2007
Posts: 1,314
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
You could have gotten some bad diesel. I seem to lose 2 MPG when I get mine from Walmart. How long has it been since you've changed fuel filters and oil? My mileage starts tanking once I hit the high 5k range on oil changes and in the 15k range or so with fuel filters. On my last trip to Florida, I thought I could make it back home before changing, but I ended up doing it on the side of the road in my mom's old folks trailer park since the economy got so bad. LOL I was down to 16 something on the road. Once I changed the oil/filter and fuel filters, I was back up to high 19s.
Reply With Quote Quick reply to this message
  #6  
Old 09-05-2008, 03:26 PM
Compression Ignition Addict
 

Join Date: Sep 2007
Location: Kill Devil Hills, NC
Posts: 4,439
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
What speed are you runngin exactly? when driving 65-68 i got around 19.3 when going 75-76 i got 17.2
Reply With Quote Quick reply to this message
  #7  
Old 09-05-2008, 05:10 PM
Member
 

Join Date: Jun 2008
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by tech10002 View Post
You could have gotten some bad diesel. I seem to lose 2 MPG when I get mine from Walmart. How long has it been since you've changed fuel filters and oil? My mileage starts tanking once I hit the high 5k range on oil changes and in the 15k range or so with fuel filters. On my last trip to Florida, I thought I could make it back home before changing, but I ended up doing it on the side of the road in my mom's old folks trailer park since the economy got so bad. LOL I was down to 16 something on the road. Once I changed the oil/filter and fuel filters, I was back up to high 19s.
The fuel filters were changed less than a 1k ago. I'd gone 45k on the frame mounted filter before the change

The Diesel was from an Exxon station that sells a lot to truckers so I think it was good.

I've never noticed a mileage change during an oil interval but I'm at 6600 miles on this change (I change at 7500mi).

The highway mileage definitely seems to have dropped with the new tune even though the city mileage went up.
Reply With Quote Quick reply to this message
  #8  
Old 09-05-2008, 05:11 PM
Member
 

Join Date: Jun 2008
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by Harohunter View Post
What speed are you runngin exactly? when driving 65-68 i got around 19.3 when going 75-76 i got 17.2
Speed was about 73-75mph for half the trip and 68-70mph the other half (VA has a 65mph limit).
Reply With Quote Quick reply to this message
  #9  
Old 09-05-2008, 05:13 PM
Member
 

Join Date: Jun 2008
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
One other note is that I'm running a slightly larger Ham radio antenna (a Tarheel antenna) now that I used to but I wouldn't think the increase in drag would account for 1.5mpg.
Reply With Quote Quick reply to this message
  #10  
Old 09-06-2008, 03:15 PM
Compression Ignition Addict
 

Join Date: Jul 2007
Posts: 1,314
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Wow. I can't believe the truck still ran with 45k on the FICM filter. LOL

You might try cleaning your EGR valve. That can cause poor fuel economy if it's getting sticky. I'd also go ahead and change the oil. I definitely start losing economy at around 5K.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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.



Thread Tools
Display Modes

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 01:09 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors