Question on Logic of Swapping 20” OEM Rims on Superduty for 17” Rims

[BarryandCassandra]

So, largely out of my depth here. I have a 2017 F350 SD, SRW, diesel, 4 door, long bed. Truck is 100% stock save for Timbrens, Bilsteins (OEM replacement 5100/4600), and a Helwig rear sway bar.

I have the 20” OEM rims, I foget the weight rating, but it is not what say Method Race Wheels for the SD are rated at. The BFGs on the truck are barely larger than OEM, and are rated 4,000 lbs per tire, approximately (3850?).

I carry a 2018 Cirrus 920 truck camper. The factory label on the unit shows the weight at 2905 lbs.

I WILL NOT be rock crawling with this camper on my truck. If the camper is off, we could do some off-road, I don’t see me rock crawling or doing crazy stuff even with the truck empty.

That said, my question is what do I gain other than a rim with a higher weight rating by going to a 17” rim/tire???d. My assumption is a stronger rim. And I realize that with more sidewall you can get better ride quality on/off road, but with the camper in the back I will NOT be airing down unless the truck is empty, thus i imagine no real improvement in ride quality unless I am driving the truck with the camper off. So I’m not sure that other than strength I’d be gaining anything by going to 17s. To me, the increase in the strength of the rims alone is possibly enough justification.

Thoughts???? Thank you in advance.

Barry

 

[bigeyedfish]

I think the steel wheels Ford offered were 18". Look around and make sure that 17s will fit with no brake caliper interference.

Aside from that, larger tires need less air pressure for a given load, so they often do ride softer than lower profile tires. They will be less stable laterally though, which is not good with a heavy camper. If I were in your shoes, I'd stick with the 20s. As long as you aren't blowing through the trucks payload rating, the wheels will be just fine.

 

[dstefan]

Will you ever be in sand or snow or muddy conditions? There are many situations where airing down and more rubber can help. In many cases it can get you unstuck where otherwise you’d need a tug.

Washboard roads are the thing that I air down for religiously. Saves my truck, camper, and occupants from shaking and vibrating to death. Airing down is definitely not just for rock crawling.

 

[RAM5500 CAMPERTHING]

I think the steel wheels Ford offered were 18". Look around and make sure that 17s will fit with no brake caliper interference.

Aside from that, larger tires need less air pressure for a given load, so they often do ride softer than lower profile tires. They will be less stable laterally though, which is not good with a heavy camper. If I were in your shoes, I'd stick with the 20s. As long as you aren't blowing through the trucks payload rating, the wheels will be just fine.

This.. All of this

 

[BarryandCassandra]

So, I have not run across scales. I am confident I’m within the OEM rim load rating. I could be in snow/mud, but I’d obviously be very aware of that and avoid if possible.

Given the concerns voiced over lateral stability with a taller sidewall tire, seems like maybe stick with what I have and get a good bumper mount winch as a safety net and tread carefully.

Lot of pros/cons to consider with everything.

-B

 

[vintageracer]

Hit the scale.

It's CHEAP to weigh and then you will KNOW your rigs weight rather than just being confident!

 

[dbhost]

Just something to consider and check out prices to verify this but I have had seventeens on my F150 since it was new and the one thing I noticed is in about 2010 the prices for 17" tires and 18 inch tires sort of flip flopped. You really will experience a smootherrive with the smaller diameter rim sure and that is a good definitely sooner have eighteen's than twenty's on a pick up but then again I'm not a 20 year old either. I want the sidewall. It may be easier and cheaper to find a proper fitment in 18" rim then in 17 is all I'm going for.

 

[tacollie]

The factory steel 17" rims have a lower load ratting than the 18"and 20". Method does offer a 17" HD rim with a 4500lbs weight rating. There are not many 17s rims that will clear the calipers. My truck came with 20s. I picked up some 18" take offs for $150 off Facebook and had some 286/75r18s mounted on them. The same size as Tremor tires. They are definitely better on washboard.

 

[alanymarce]

Adding to others' comments:

if you plan to travel in dunes you need to air down, the less difference between rim diameter and tyre diameter the less you can extend the footprint.

Airing down for corrugations is a matter of opinion - we've tried decreasing tyre pressure, increasing it, and leaving it at normal, and our experience is that reducing pressure doesn't help much, as long as you're running standard pressures to start with and your spring dampers are in good condition.

 

[montypower]

I'd be concerned about your loaded weight. That's a HEAVY camper for SRW truck. Get your front/rear loaded axle weights! Then you can look into wheel and tire options.

17s are popular for the taller tire sidewall profile. But tire availability and required weight capacity may dictate your ideal wheel diameter. I'm excited to see Toyo offering the RT Trail and AT3 in 37x12.5R17 with 3,970lb rating. 17" Method HD wheels will give you 4,500lb rating.

Need to work backwards to determine what will fit your needs.

 

[IdaSHO]

18's will likely offer a better selection of tires.

I went from 17's to 18's for my truck to get the 4080lb rated 35" Toyos

We roll at 11,500 to 12k loaded with zero worries.

 

[Todd780]

Just something to consider and check out prices to verify this but I have had seventeens on my F150 since it was new and the one thing I noticed is in about 2010 the prices for 17" tires and 18 inch tires sort of flip flopped. You really will experience a smootherrive with the smaller diameter rim sure and that is a good definitely sooner have eighteen's than twenty's on a pick up but then again I'm not a 20 year old either. I want the sidewall. It may be easier and cheaper to find a proper fitment in 18" rim then in 17 is all I'm going for.

Not sure about the Super Duties, but on the F150 it depends.
Factory 18's come with a 60 or 65 series tire. the 20's come with a 60 series. So either way, not a lot of difference in sidewall.

 

[dbhost]

Not sure about the Super Duties, but on the F150 it depends.
Factory 18's come with a 60 or 65 series tire. the 20's come with a 60 series. So either way, not a lot of difference in sidewall.

1" to be specific...