Mpg difference between 250 and 350

[Fordman2000]

Hey everyone. I am looking at two comparably equipped trucks. They both are SRW, 3.31 gears, and crew cabs. I was wondering if the 350 (11200# package), would get less moles per gallon than the lighter 250. They are both short beds as well. Thanks!

[Painted Horse]

No. I seriously doubt you will see any noticable difference in fuel mileage between two similarly equiped (F250 vs F350) trucks. The slight difference in the spring package doesn't really change the weight or wind resistence of these trucks.

I've driven several of these trucks cross country. Both F250 with the 3:31 & 18" wheels and F350 with the 3:55 and 20" wheels, and my freeway mileage has been almost exactly the same.

[gsxr1300]

they basically weigh the same
same truck just with an extra leaf spring

[BIG Laing]

Originally Posted by Fordman2000

Hey everyone. I am looking at two comparably equipped trucks. They both are SRW, 3.31 gears, and crew cabs. I was wondering if the 350 (11200# package), would get less moles per gallon than the lighter 250. They are both short beds as well. Thanks!

Same gears, same mpg. Why do you want 3.31 gears. Jw

[Fordman2000]

Thanks for the info. I was thinking about those gears because I am not going to be towing much weight. I will have a 16ft enclosed trailer weighing roughly 4-6000lbs. From what I have heard, these gears would give me the best chance at good fuel mileage.

[gsxr1300]

Both gears have the same tow rating
3:31 with 18" wheels
3:55 with 20" wheels
With the difference in tire diameter the ratios are basically the same

[BIG Laing]

Originally Posted by Fordman2000

Thanks for the info. I was thinking about those gears because I am not going to be towing much weight. I will have a 16ft enclosed trailer weighing roughly 4-6000lbs. From what I have heard, these gears would give me the best chance at good fuel mileage.

If your never plan on towing over 10k lbs or lift and tires, then the 3.31 is the right choice. I would get the 250 though as the cost of ownership is less.

Originally Posted by gsxr1300

Both gears have the same tow rating
3:31 with 18" wheels
3:55 with 20" wheels
With the difference in tire diameter the ratios are basically the same

He was looking at trucks with 20" rims, which you can get on all the srw axle trucks.
You are right though, if those were the variables.

Circumference / ratio = distance traveled per driveshaft revolution.
109.272" (34.8x3.14) / 3.55 = 30.781"
102.992" (32.8x3.14) / 3.31 = 31.115"

Very close!

[gsxr1300]

Oh i didnt know you can get 3:31 with 20's you couldnt when i got my truck

[Painted Horse]

You can't get 20" with the 3.31. They would have to be aftermarket.

As far as the cost of ownership. It depends on you state. Here is Utah the property taxes are based on the trucks value ($) not its weight.

It is interesting to see all the folks complaining about sagging with F250, Why didn't they just the F350 to start with if they knew they were going to tow.

[BIG Laing]

Originally Posted by gsxr1300

Oh i didnt know you can get 3:31 with 20's you couldnt when i got my truck

Originally Posted by Painted Horse

You can't get 20" with the 3.31. They would have to be aftermarket.

As far as the cost of ownership. It depends on you state. Here is Utah the property taxes are based on the trucks value ($) not its weight.

It is interesting to see all the folks complaining about sagging with F250, Why didn't they just the F350 to start with if they knew they were going to tow.

A co-worker of mine has 3.31's and fords chrome clad 20" rims. I will ask him how he got them, Next time I bump into him.

I would include insurance in cost of ownership, 3/4 ton has cheaper insurance then 1 ton. Well at least with state farm, it was less then $10 a month diff, but still a diff.