Need help with MPG
Thread Starter
|
New User
Joined: Jan 2014
Posts: 5
Likes: 0
Need help with MPG
Just got this truck after Christmas. I am on the 3rd tank of fuel and have been averaging just 8.5 mpg. I let the truck warm up and drive it about 25 miles 4 times a week. but also around town on the weekend. Just had new oil, filter, fuel filters, and checked all fluids. It is not burning any coolant, no chip, stock exhaust. My 1990 f-250 7.3 IDI was getting 14?
Elder User
Joined: Apr 2006
Posts: 524
Likes: 0
From: Taylorsville, UT
Couple of questions for you. 1. How long are you idling to let it warm up? This is a big mileage killer. 2. Are you hand calculating the milage or going off the computers mileage? This will get things going in the right direction for you on future questions/answers.
Thread Starter
|
New User
Joined: Jan 2014
Posts: 5
Likes: 0
I will let it warm up for 8-10 min. Just enough time to get my lunch and tie my boots. and i am calculating the mileage off a app i have on my phone. it just basically keeps a record of fuel cost and mpg. Also it is a 2003, F-250, 4 Door, Short bed, 4X4.
Fleet Owner
Joined: Nov 2003
Posts: 27,872
Likes: 3,592
Things to check:
1. Codes (DTC's)?
2. Tire pressure?
3. Stuck brake caliper?
4. Hubs in 4x4 (if it is a 4x4)?
5. EGR valve clean?
6. FICM voltage (MPower)?
7. Air filter clean?
8. Key sensors clean (pull and check)? - MAF/IAT1, IAT2, MAP, EBP, etc
9. Is it slow cranking? (maybe the A/C compressor is bad and dragging)
10. Fuel pressure? (will need an add-on sensor and gauge)
Edit - just saw your answer to utjer's post ...........
That idling can definitely KILL your fuel economy (as utjer said).
1. Codes (DTC's)?
2. Tire pressure?
3. Stuck brake caliper?
4. Hubs in 4x4 (if it is a 4x4)?
5. EGR valve clean?
6. FICM voltage (MPower)?
7. Air filter clean?
8. Key sensors clean (pull and check)? - MAF/IAT1, IAT2, MAP, EBP, etc
9. Is it slow cranking? (maybe the A/C compressor is bad and dragging)
10. Fuel pressure? (will need an add-on sensor and gauge)
Edit - just saw your answer to utjer's post ...........
That idling can definitely KILL your fuel economy (as utjer said).
Mountain Pass
Joined: Mar 2009
Posts: 183
Likes: 12
So being new to the diesel world, now I'm confused. I was told to make sure to give these things ample time to warm up or your fuel economy will be horrible. So just like Kelley, I'm giving roughly 10 minutes to warm up as well.
So what is a good rule of thumb in normal, cold and frigid temps?
1 min?
2 min?
Start and drive, but take easy for X miles?
Just like Kelley, I'm seeing fairly low (12.65) economy.
I discovered my hubs were locked
("here's my sign..."), so that should help a little as well.
So what is a good rule of thumb in normal, cold and frigid temps?
1 min?
2 min?
Start and drive, but take easy for X miles?
Just like Kelley, I'm seeing fairly low (12.65) economy.
I discovered my hubs were locked
("here's my sign..."), so that should help a little as well.
Logistics Pro
Joined: Dec 2004
Posts: 4,138
Likes: 7
From: South Weber, Utah
I let the truck idle for 2-3 minutes and head out just keeping the RPM's and ICP pressure down while the oil heats up. Winter fuel yields lower MPG and the extended idling doesn't help your MPG. Short hops in stop and go style driving also hurts the mileage. Having larger than factory tires will show lower MPG as well. The best way to calculate MPG is to bust out the calculator every time you hit the pump and filling it until the pump clicks off, some guys like to top it off to where they cant get another molecule of fuel into the tank but I am not in this club, when the pump clicks off I call it good. 12.6 MPG on winter fuel in a cold climate isn't too bad, now 8.5 is way low. Running cetane boost is a good thing to do and running the block heater during cold weather isn't a bad idea either.
Trending Topics
Mountain Pass
Joined: Mar 2009
Posts: 183
Likes: 12
Also, this may sound stupid to some, but what about stop light behavior...
In gassers, it's better to ease up to speed. Is that the same with a diesel, or would it be better to jump up to speed and level out.
Common sense to me says same same...but better be sure.
The thought came to me this morning as I was easing off the line and took quite a while to get up to speed. Does it use less fuel to ease up to 55 over the course of (for conversations purpose) a city block, goose it and get there asap.
I've been focusing on keeping the RPM's below 2k when I accelerate. Jumping up to 3k makes a huge difference in acceleration. What about consumption?
In gassers, it's better to ease up to speed. Is that the same with a diesel, or would it be better to jump up to speed and level out.
Common sense to me says same same...but better be sure.
The thought came to me this morning as I was easing off the line and took quite a while to get up to speed. Does it use less fuel to ease up to 55 over the course of (for conversations purpose) a city block, goose it and get there asap.
I've been focusing on keeping the RPM's below 2k when I accelerate. Jumping up to 3k makes a huge difference in acceleration. What about consumption?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Elder User
Joined: Apr 2006
Posts: 524
Likes: 0
From: Taylorsville, UT
Here is what I experience. Summer time here in UT I run average 16mpg mixed driving/19 highway. Winter I am running 14 mpg mixed/17 highway (winter fuel). I plug my truck in each night so I dont have to warm it up in the morning. I let it idle about 30 secs to a min to get the fluids moving and go. 2 years ago I never plugged it in and in the winter with warm ups of up to 5 mins or so I was averaging around 12 mpg. I do use diesel kleen each tank for a cetane boost. I hand calculate my mpg since the meter on the truck is either off by a mile per gallon either direction or dead one (cant be trusted).
Posting Guru
Joined: Dec 2012
Posts: 2,169
Likes: 3
From: SW Florida
The only "accurate" way to determine MPG is to hand calculate...total miles driven divided by gallons used at fill-up. If you have larger or smaller tires than stock, that has to be calculated into it. (there may even be an app out there to show how to do this)
Do you have stock tires/wheels?
Mountain Pass
Joined: Mar 2009
Posts: 183
Likes: 12
I'm using a phone app to calculate as well. They don't calculate the same way the on board lie-o-meter does. It's just an automated version of the hand calculation.
You input the current odometer, the amount of gas it took to fill back up, and the cost per gallon. It keeps track of mileage and also expenses over time.
So every time you fill up, it tells you what your avg econ is since your last fill up.
You input the current odometer, the amount of gas it took to fill back up, and the cost per gallon. It keeps track of mileage and also expenses over time.
So every time you fill up, it tells you what your avg econ is since your last fill up.
Elder User
Joined: Aug 2010
Posts: 675
Likes: 1
From: NV
Also, this may sound stupid to some, but what about stop light behavior...
In gassers, it's better to ease up to speed. Is that the same with a diesel, or would it be better to jump up to speed and level out.
Common sense to me says same same...but better be sure.
The thought came to me this morning as I was easing off the line and took quite a while to get up to speed. Does it use less fuel to ease up to 55 over the course of (for conversations purpose) a city block, goose it and get there asap.
I've been focusing on keeping the RPM's below 2k when I accelerate. Jumping up to 3k makes a huge difference in acceleration. What about consumption?
In gassers, it's better to ease up to speed. Is that the same with a diesel, or would it be better to jump up to speed and level out.
Common sense to me says same same...but better be sure.
The thought came to me this morning as I was easing off the line and took quite a while to get up to speed. Does it use less fuel to ease up to 55 over the course of (for conversations purpose) a city block, goose it and get there asap.
I've been focusing on keeping the RPM's below 2k when I accelerate. Jumping up to 3k makes a huge difference in acceleration. What about consumption?
Lead Driver
Joined: Jan 2005
Posts: 7,782
Likes: 221
From: Huntington Indiana
We get 14 running around and 18-20 freeway. I would check to see if tires you have on are the same as what is listed on the door. If not then the mileage would be different based on the size of tire changed. Google tire ice and I remember finding a calculation from one size to another in mileage change.
Thread
Thread Starter
Forum
Replies
Last Post