ro90u14
SDD Junior Member
I am trying to decide on a 2013 F350 or F450 (6.7 powerstroke). I will be pulling a 19K fifthwheel toyhauler. Does the axle ratio on the F350 vs F450 drastically change the gas mileage?
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DaveBen
SDD Senior Member
to SDD. Glad you joined up here. The axle it self does not make a difference in your mileage, BUT the gear ratio DOES make a big difference. The lower the gear ratio, the better mileage. 3.55 gears will get much better mileage than 4.10 gears. It is a trade off between towing and mileage.Dave
ro90u14
SDD Junior Member
thanks. So If I decide to go with the 3.55 and change tire size from the 17's to 19.5 will this make a difference in gas mileage also?
BIGMike
Full Access Member
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DaveBen
SDD Senior Member
The total DIAMETER of the wheel and tire are what determines the change in the ratio. Give us what you have and what you want, in total inches diameter, and we can tell you if your ratio is going up or down.
Dave
Dave
First you need to figure out is this a drive every day truck towing on the weekends, or towing everyday. You can change the rims size as long as the tire DIAMETER does not change. Other words smaller sidewalls. The newer trucks have no problem pulling with the 3.55 gears just use the tow mode on the truck. This changes the shift point in the trans. and can keep you in the power ban longer. It also uses the trans. as a brake for stopping with heavy loads.
02SilverStroke
Full Access Member
Welcome aboard!!!!!
ro90u14
SDD Junior Member
I will be towing a 19K fithwheel toyhauler most of the time.
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WD40
Full Access Member
19K is a load for a F350 and you would be over loaded. So it looks like the F-450 is what you
need to be looking at. I pull at 35 foot fifthwheel and it's right at 17 most of the time and it puts
my gross at 25,500, just under needing a CDL, but I already have that. LOL
