I took delivery of a new 26 ft camper that weights just under 6,000 pounds. GVWR is 7,650, but it is empty right now. I live in Texas which has a lot of rolling hills. It rarely goes into over drive, so it stay sin 3rd gear and every time I hit a hill, it downs shifts to 2nd gear. Boy that motor can scream!


My truck has the 3.7? ratio. I remember someone here mention that don't spend the money for 4.10, go straight to 4.30 for better performance. If I do that, will it stay in OD longer? I got 8 MPG, but I was expecting better MPG. If I go for 4.30 will it get better MPG for not down shifting a lot?


Thanks


2001 F250 5.4 Crew Cab RWD.

 

Gear swap would be a good option for you since you only have one axle to change. The higher the ratio, the less milage you get, but you will gain pulling advantage. If I have it right, the engine will spin as high in OD with the 4:?? as it will spin a gear lower with the 3:?? gears so it may be a wash.

 

That was me and I'll say it again if you have stock tires go straight for f 4.30's there isnt enough of a difference between 3.73 and 4.10 to make it worth the cost. it should get you in to od and help you keep it there just don't expect it not to down shift ever and you still won't be turning as many rpms as you are in 3rd now these mod motors like gears they all should have come with 4.30's stock

 

How much do you tow vs non tow? You have a 3.73 rear end and with that tranny, you should not tow in OD, just shift down to 3rd and not be in a hurry. Moving up to the 4.30 range will inhibit top end when not pulling...severely, not to mention mpg.
I've towed a 10k toy trailer with our 5.4, 3.73 re and it wasn't pretty going uphills.
Most of the time prior to my 6.0, I'd pull our 6500 lb boat and I wasn't the fastest up the hills, but I got there.
I'd move to 4.10's if you want improvement for towing, knowing the downside. Unless you tow most of the time, 4.30's is too much IMO.

 

4.30's sound the way to go. Do you plan on upping the tire size any? If yes a deeper gear may be better to keep you closer to the 4.30 ratio. Thought about adding a limited slip like the Eaton Tru-Trac? Also may be time to entertain a SPD y pipe either through SPD or 5 star.

Y Pipe 2000 - 2005 for 5.4L / 6.8L/ Excursion EX0005AL - 5 Star Tuning

http://185.56.86.85/~five2/wp-conten...stall_pics.pdf

 

The 4R100 can tow just fine in OD. If you are hunting gears than turn OD off. With it on it will cool better. 4.30 and 4.10 ratio's were both factory options, at the same time some members who do tow with a 5.4 have said they could have gone deeper without an issue.

 

I have no plans to go with larger tire size. Stock size is 264 75 16