Modular V10 (6.8l)  

7 mpg??

Thread Tools
 
Search this Thread
 
  #1  
Old 11-09-2012, 09:55 PM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
7 mpg??

Alright, let's get this right out of the way right up front. I realize I own a big, heavy 1-ton truck with 10 hungry mouths to feed under the hood. Thus, I'm not expecting miraculous mileage. But based on what I've read on here, it seems my mileage is sub-par. So I'm gonna ask for some guidance.

I took the ATVs into the woods last weekend -- probably the last trip I'll get this year, as there was already 10+ inches of snow on the road at the highest elevations. I was pulling a small NON-enclosed trailer with 2 quads. Total weight: about 2500lbs. And I reported 7mpg. I was stunned...in a bad way. I've heard of guys on here getting 7mpg, but it's usually been pulling 8k, 10k, maybe 12k pounds. This was <3000lbs. I'm very nervous about what kind of mileage I'm going to be getting next summer with the 4000# camper in the bed AND the ATV trailer in tow.

In town lately, I'm getting ~10mpg. I normally drive 40-50mph with few stop signs or stop lights, and I drive with OD locked out. I kinda expect more than 10mpg given these conditions. And on the freeway, running 70-75mph, I'm not much better than 10-11mpg. Again, based on others' feedback here, seems I should be getting better.

The truck is totally stock. It's not throwing any codes, and seems to run and idle perfectly. No misses or anything like that. I will say that first thing in the morning, the exhaust smells like it's running very rich. But I think that's probably typical of early morning starts around here, especially since the weather turned cooler.

Truck has a new air filter, new fuel filter, and I just cleaned the MAF sensor a couple of weeks ago.

What are some of the items I should go after next?
 
  #2  
Old 11-10-2012, 04:32 AM
CPaulsen's Avatar
CPaulsen
CPaulsen is offline
Senior User
Join Date: Apr 2011
Location: Southern Oregon
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
I changed my MAF and used Seafoam for the injectors. Lowest I have gotten is 8mph pulling my 5th wheel(18,400 gross truck and trailer) and back and forth to work is averaging 13-14. Have got as high as 16.5 before.
 
  #3  
Old 11-10-2012, 08:00 AM
mikeismadness's Avatar
mikeismadness
mikeismadness is offline
Posting Guru
Join Date: Aug 2007
Location: laporte in
Posts: 1,858
Likes: 0
Received 5 Likes on 5 Posts
Without more info on the truck I can't accurately give you info. Tire size, gear, chassis configuration, and weather play a factor. Although everyone else sees up to 14 highway, my average is right around 10.2 driving 60% highway at 60. I run slightly larger tires, have 4.10s, 4x4 CCSB. You said snow and spinning and slipping around is gonna net worse fuel mileage also. Plus I have a 3v which generally has a lower mpg rating than the 2v
 
  #4  
Old 11-10-2012, 09:09 AM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
My signature has a lot of that info, but it was missing tire size. I updated the sig this morning to include tire size.

As for the snow, I should've been more clear. We encountered snow while riding ATVs. NOT while driving. Snow was up above 7500 feet, and we parked around 6000 feet.
 
  #5  
Old 11-10-2012, 09:56 AM
rvpuller's Avatar
rvpuller
rvpuller is offline
Moderator
Join Date: May 2004
Location: Home Base Nebraska
Posts: 6,041
Received 428 Likes on 280 Posts
Your signature says your running 285/75/16 tires (32.8 dia) but stock is 265/75/16 tires (31.6 dia) that changes your final gear ratio and if your computer was not changed to that tire size your odometer will be off so your mileage calculation is off. Also pull all your wells and check the slide pins on all the calipers to make sure they are moving freely, dragging brakes will kill gas mileage.

Denny
 
  #6  
Old 11-10-2012, 10:39 AM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
What was your procedure for cleaning the injectors with Seafoam? Did you just add a bottle to a tank of gas, or did you use a method that's more potent/concentrated?


Originally Posted by CPaulsen
I changed my MAF and used Seafoam for the injectors. Lowest I have gotten is 8mph pulling my 5th wheel(18,400 gross truck and trailer) and back and forth to work is averaging 13-14. Have got as high as 16.5 before.
 
  #7  
Old 11-10-2012, 10:59 AM
galaxie641's Avatar
galaxie641
galaxie641 is offline
Postmaster
Join Date: Nov 2006
Location: SE Wyoming
Posts: 4,517
Likes: 0
Received 3 Likes on 3 Posts
Sounds like you are right in the ballpark, remember mpg quotes tend to turn into pissing matches. Your best mileage should come around 60mph in OD and with that camper and a trailer I wouldn't expect much over 10mpg.
 
  #8  
Old 11-10-2012, 11:20 AM
mikeismadness's Avatar
mikeismadness
mikeismadness is offline
Posting Guru
Join Date: Aug 2007
Location: laporte in
Posts: 1,858
Likes: 0
Received 5 Likes on 5 Posts
7 sounds perfect if he's climbing elevation
 
  #9  
Old 11-10-2012, 03:09 PM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
I would've been ecstatic with 10mpg at 60mph with the camper loaded. Based on last weekend's experience, I'm fearing it'll be half of that. With my current setup, anyway. I'm planning on swapping spark plugs and a can of Seafoam to start with to see if that improves things any.

I have long-term plans for 4.56 axles and a 5-star tuner. This beast is going to be a towing/hauling vehicle, so I may as well set it up for those duties accordingly.


Originally Posted by galaxie641
Sounds like you are right in the ballpark, remember mpg quotes tend to turn into pissing matches. Your best mileage should come around 60mph in OD and with that camper and a trailer I wouldn't expect much over 10mpg.
 
  #10  
Old 11-10-2012, 03:23 PM
bakon's Avatar
bakon
bakon is offline
Elder User
Join Date: Apr 2010
Location: Steeler Country
Posts: 619
Likes: 0
Received 5 Likes on 5 Posts
I think you are not going to see much or any improvement. Also ethanol in the gas kills milage, hills, trailer 2500lbs is still dragging 2500lbs uphill. Tire size is bigger... you are pretty much where you are going to be.
 
  #11  
Old 11-10-2012, 03:29 PM
AlaskanEx's Avatar
AlaskanEx
AlaskanEx is offline
Bleed Ford Blue

Join Date: Apr 2009
Location: Anchorage Alaska
Posts: 13,574
Received 128 Likes on 43 Posts
if you feel bad about that, i get 7-8mpg daily driving all winter long. idle time, running in 4x4, stop and go kill it. summer i get closer to 10 mpg.

sounds like you did just fine to me.
 
  #12  
Old 11-10-2012, 03:54 PM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
Ooh, good call on the ethanol. I know for a fact that the station I filled at on my way out of town has 10% ethanol mixed (stupid gov't mandates...). There are stations near me that sell 100% petro, though. I'll give that a shot and see what improvement, if any, I observe.


Originally Posted by bakon
I think you are not going to see much or any improvement. Also ethanol in the gas kills milage, hills, trailer 2500lbs is still dragging 2500lbs uphill. Tire size is bigger... you are pretty much where you are going to be.
 
  #13  
Old 11-11-2012, 12:27 PM
truckfella's Avatar
truckfella
truckfella is offline
Elder User
Thread Starter
Join Date: Jul 2005
Posts: 974
Likes: 0
Received 6 Likes on 3 Posts
I spent some time Google'ing this morning regarding ethanol blended gasoline.

While the EPA reports that only a 3% reduction should be expected with E10 (what the heck do they know, though, right?), most of the actual reports I've seen is that a reduction of at least 10% is to be expected.

Being the engineer that I am, sounds like a controlled experiment is in order!
 
  #14  
Old 11-11-2012, 12:43 PM
WestxSRT10's Avatar
WestxSRT10
WestxSRT10 is offline
Elder User
Join Date: May 2008
Location: SW Idaho
Posts: 574
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by truckfella
Ooh, good call on the ethanol. I know for a fact that the station I filled at on my way out of town has 10% ethanol mixed (stupid gov't mandates...). There are stations near me that sell 100% petro, though. I'll give that a shot and see what improvement, if any, I observe.
I can't find any stations here that sell 100% gas?

Going with a 5Star tune may be your best bet, it sure helped my truck get 1 mpg more.

I get 9.2 towing a 9K 5th wheel.
11.5 average empty
Just made a return trip from So Cal and got 14.7 mpg. (empty) My overhead monitor still reads 14.5.
 
  #15  
Old 11-11-2012, 03:43 PM
Snellville-Dave's Avatar
Snellville-Dave
Snellville-Dave is offline
Junior User
Join Date: Dec 2003
Posts: 95
Likes: 0
Received 0 Likes on 0 Posts
I think altitude is part of your problem. If you can't get ethanol free gas, get some stabil blue to mix in the gas. Also sometime try to run 60-65 mph for a while. Dave
 


Quick Reply: 7 mpg??



All times are GMT -5. The time now is 12:22 AM.