15 DRW Wheel Width
#32
The size can vary based on air pressure, but here are some quick reference numbers based on the RPM values you gave me.
The 60 and 65 numbers don't quite line up, but they appear to be true to the calculated size of 33.1" based on the 55 and 70 numbers.
I like the tires.
Speed - Gear - Tire Size - RPM
Keith
#33
It's difficult to get accurate RPM readings without digital, tires were aired to 75psi Front, 65psi rear. Outside air temp was 90 degrees so I had put about 10 mi on towing 19K and then another 5mi when obtaining those rpms and speeds so I expect tire pressure had risen by 10 - 15 psi do to temp.
#34
#35
#36
Right, I think you will be totally fine. You have the 440/860 motor which should handle 19k just fine, even at the "simulated" 3.55 ratio you essentially have now with the larger tires. I was just saying a 2017 dually with the 3.55 axle is still rated to something like 27k lbs.
#37
#38
My preference would have been 3.73 gears. But the only options were 3.55 and 4.10. Since I do a lot of highway driving, I took the 3.55 and lost 4k in maximum towing capacity. But so far, the 3.55 has been great. I think you're right...Ford figured with the extra 65lb-ft to play with they could offer that lower gear ratio. On the other hand, it is a brand new axle (Dana M300) compared to the old axle (Dana 80 / S110, not sure) so maybe it was a Dana limitation for that axle.
#39
1st loaded trip out on Toyo 255/80/17 Open Country AT 2.
I took the rig out for a longer loaded haul from SoCal to the Eastern Sierras and the handling change is impressive over the stock General tires, much more stable on the road; as far as the gearing change from taller tires barely noticeable. If you are thinking of a similar change of tires I say do it sooner than later, my Generals had at least another 5K of tread left (29K) but after I removed them and really started inspecting them closer they were cracking in the bottom of the tread on 2 year old tires. Lucky no blow outs as I had just returned from a 2500 mi. trip towing.
I took the rig out for a longer loaded haul from SoCal to the Eastern Sierras and the handling change is impressive over the stock General tires, much more stable on the road; as far as the gearing change from taller tires barely noticeable. If you are thinking of a similar change of tires I say do it sooner than later, my Generals had at least another 5K of tread left (29K) but after I removed them and really started inspecting them closer they were cracking in the bottom of the tread on 2 year old tires. Lucky no blow outs as I had just returned from a 2500 mi. trip towing.
#40
1st loaded trip out on Toyo 255/80/17 Open Country AT 2.
I took the rig out for a longer loaded haul from SoCal to the Eastern Sierras and the handling change is impressive over the stock General tires, much more stable on the road; as far as the gearing change from taller tires barely noticeable. If you are thinking of a similar change of tires I say do it sooner than later, my Generals had at least another 5K of tread left (29K) but after I removed them and really started inspecting them closer they were cracking in the bottom of the tread on 2 year old tires. Lucky no blow outs as I had just returned from a 2500 mi. trip towing.
I took the rig out for a longer loaded haul from SoCal to the Eastern Sierras and the handling change is impressive over the stock General tires, much more stable on the road; as far as the gearing change from taller tires barely noticeable. If you are thinking of a similar change of tires I say do it sooner than later, my Generals had at least another 5K of tread left (29K) but after I removed them and really started inspecting them closer they were cracking in the bottom of the tread on 2 year old tires. Lucky no blow outs as I had just returned from a 2500 mi. trip towing.
Having 4 worn out would make the upgrade easier to swallow though. I really want the bigger tire.
#42
#43
#44