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2008 Ford E250 MPG

bikerpaul

bikerpaul

Expert Expediter
I'm getting 16.0 to 16.25 mpg with my E250. It has a 4.10 rear end gear, and the 4.6 liter engine. The only thing I've added is a K&N air filter, which didn't help much that I can see. I'm debating going to a 3.73, 3.54, or a 3.24 rear end gear to help the mileage. Does anybody have any helpful thoughts on this? I have been driving in the 60 to 65 speed range. Thanks in advance.
 
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skyraider

skyraider

Veteran Expediter
US Navy
I am in the same mileage range on my dodge one ton 318 v8 throttlebodyt,slowing down as u are doing is the biggest savings on mileage, works for me that way. changing rear ends will also affect ur computer presets. Just keep doing what ur doing, a friend of mine has the same ford engine, he gets 17 mpg most of the time,,run ur van at 62 mpg with ur GPS, u will still get there in the same amount of time if u do 70mph. It cost money to push these lead sleds thru the air:D
 
guido4475

guido4475

Not a Member
I have a freind who has a Ford gasser, and is getting close to 18 mpg out of it by changing the exchaust to a Flow master.

On a different note, I have another freind who has the exact same van as I do-year, engine, model,trans, etc.

He changed his rearend gears to the factory optional 3:55 from a 4:09. he is getting 21 mpg average.He has shown me his fuel record, and like me, keeps track of his mileage with each and every tankful.

I have the Factory 4:09 gears in my van, and am getting around 16 mpg.

So, yes, it is worth a gear change.Him and I both drive about the same, as we have figured out.
 
greg334

greg334

Veteran Expediter
The ration is picked for a reason - to give you the performance that people expect to get while returning the mileage within the range of the engine's Volumetric Efficiency.
 
piper1

piper1

Veteran Expediter
Owner/Operator
Greg is right. On any application, class 8 to a van you need to be very careful when you start talking about changing rear end ratio's. A van with a 4.6 will not react the same as a van with a diesel when you are talking ratio's. Dropping to a 3.55 will do you no good if all it does is lug the engine and cause a lot of downshifts on hills. With the small engine I would not want to drop that low.
 
guido4475

guido4475

Not a Member
I wasnt really coming out and telling him what gear ratio to put in, but merely giving an example of what it could do for a vehicle.
 
greg334

greg334

Veteran Expediter
Actually Guido, I didn't even see your post. I had the post box up for a bit before I started the reply.
 
Jack_Berry

Jack_Berry

Moderator Emeritus
my 4.6 has gotten as high as 19 a few times. regularly in the 15-17 range with the familiar reasons. driven at 2000 rpm. below is the last time the epa tested the full size e250 cargo van. your mileage is average.


Find a Car
 
bikerpaul

bikerpaul

Expert Expediter
Most of my loads are under 500 lbs. Just a few over that, with one at 1973 lbs. From what I understand from these posts, I should go with a 3.73 or 3.54, nothing below that. I am not looking for performance, just better gas mileage. The 4.10 gear was the optional gear for this vehicle, and it was a rental vehicle before I got it at 11,000 miles. The standard gear for this model was the 3.73. Any help is appreciated in helping with this decision.
 
skyraider

skyraider

Veteran Expediter
US Navy
They are right about increase in downshifting if u change rear ends and it can lug the engine. My 318 with 2500 lbs is not rocket sled when the cargo goes that high. I would leave it alone,,,just slow down to 62mph, works for me and mine is a one ton,,u should do better,,try it, and throw ur ego out the window on high speeds, ur wasting gas over 65mph,,62 is a good speed and u c the world go by.:D
 
Mike99

Mike99

Veteran Expediter
bikerpaul said:
Most of my loads are under 500 lbs. Just a few over that, with one at 1973 lbs. From what I understand from these posts, I should go with a 3.73 or 3.54, nothing below that. I am not looking for performance, just better gas mileage. The 4.10 gear was the optional gear for this vehicle, and it was a rental vehicle before I got it at 11,000 miles. The standard gear for this model was the 3.73. Any help is appreciated in helping with this decision.
Click to expand...
What is the cost to do this?
 
greg334

greg334

Veteran Expediter
But I think you may miss the point.

Volumetric efficiency is what the manufacturer strives for. That is where the engine does its best in both power and fuel consumption but they calculate the gear rations to achieve this while giving the expected performance.

For example some will say that at 62 mph, they get the best mileage - which equates to say 2250 rpm. Now if they change the gearing in the rear and they go to something that gives them 67 mph at 2250 rpm they can get worst mileage.

How?

The engine is working the same speed but the torque needed to keep the vehicle moving at a higher speed has increased. With this the needed torque to move a vehicle up hills has now increased because the gear ration is different.

I'm not against changing the gearing but because the engine is small, it may hurt things more and be a waste of money in the long run.
 
jw-bama

jw-bama

Seasoned Expediter
greg334 said:
But I think you may miss the point.

Volumetric efficiency is what the manufacturer strives for. That is where the engine does its best in both power and fuel consumption but they calculate the gear rations to achieve this while giving the expected performance.

For example some will say that at 62 mph, they get the best mileage - which equates to say 2250 rpm. Now if they change the gearing in the rear and they go to something that gives them 67 mph at 2250 rpm they can get worst mileage.

How?

The engine is working the same speed but the torque needed to keep the vehicle moving at a higher speed has increased. With this the needed torque to move a vehicle up hills has now increased because the gear ration is different.

I'm not against changing the gearing but because the engine is small, it may hurt things more and be a waste of money in the long run.
Click to expand...

not to mention wind drag.at 67 mph its much more that at 62
 
skyraider

skyraider

Veteran Expediter
US Navy
Im slow,,,so how many cubic inches is 4.6, I was raised on the cubic inch era of life,,,could someone tell me , and the number of cylinders
 
skyraider

skyraider

Veteran Expediter
US Navy
finally found the formula to convert cc to ci, ur rite 280c.inches, 225 hp, should do ok, dont know how good they hold up. My 318ci equals to 5,211 cc, and the ford is 4600 cc.

1 cc = .0610237441 cubic inches, so 1 liter= 61 cubic in.

probably way TMI :D
 
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Jack_Berry

Jack_Berry

Moderator Emeritus
i got 250k from my engine. had the mech take the cover off and check the timing chain. it was good but the crank was moving back and forth about .125/1/8 of an inch in an allowable tolerance of something in the tens of thousandths.

the 280 inch engines might look appealing but remember you will need power to pass sometimes on 2 lane roads and the 225 hp is a lot of sound and fury. takes a long time to get momentum going in a 2 1/2 ton brick. also the ford 4.6 has an issue with the lack of return journals in the back right side of the engine. coolant forces itself out of the bolt in the back of the intake gasket. design defect by design.

you want smaller cuz you think its good go ahead but buy bigger as greg pointed out in the 4.8 or 6.0 thread. i will next time.
 
Jack_Berry

Jack_Berry

Moderator Emeritus
one more thing.....had an 1800 lb load in back the other day from ky to maine. on cruise over the short smaller hills the cruise kicked on going from 2000 to 2500 for a spell. on the taller hills it went to 2500 then 3000. no torque at 2000 in the small motor. i really think 6 liters is the smallest engine requirement for a gas van.
 
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