Newbie needs assistance with tire choice for new to me 2020 F550 4x4 Overlander

Vampergt4

Member
My wife and I are planning a 20,000 mile trip from Atlantic Canada to Alaska, then Baja and South America. I recently purchased a 2020 Unbound Freedom Overlander F550 4x4 Diesel with 11k miles. We looked at many vehicles but my wife's only requirement was it needed to have a dry bath and this one was chosen. Most of our trip will be 90% on paved roads with 10% on dirt or fire roads. Our goal is to try and make the ride smoother without compromising fuel economy. After 3 plus weeks of research, I am looking for feedback on my 3 options and other suggestions I should consider.

Option 1 - Order 7 new 19.5 x 6.75 steel wheels and install new 265 70r19.5 Toyo M608z tires
Pros - No lift required, may be a smoother ride (can someone confirm), extra ground clearance
Cons - I have read mixed reviews on the Toyo's that they sway in this configuration, costly option if no ride improvement

Option 2 - Order complete DBL kit with new 20 inch wheels, MPT 81's, small lift, new gears and new Fox shocks
Pros - Looks cool, smoother ride??? Better resale? Ability to air down
Cons - Costly. Will the additional height induce sway? The MPT 81 seem hard to balance and do not last very long. Harder on fuel

Option 3 - Stick with the stock wheels/tires and install a new Autoflex full rear air suspension (similar to Kelderman but based in Canada)
Pros - Smoother ride???? The existing ride is very planted but harsh
Cons - Not crazy about the look

Looking forward to your input.
 

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mog

Kodiak Buckaroo
Option 3 - Stick with the stock wheels/tires and install a new Autoflex full rear air suspension (similar to Kelderman but based in Canada)
It would be useful to know what your current wheels/tires are. The factory website lists The military-grade 41” tires offer maximum off-road capabilities without comprising highway use. A raised suspension on Fox 2.0 shocks handles even the toughest terrain.
 

Vampergt4

Member
Present set up is Ford OEM steel wheel 19.5 x 6 wide running 225 70 r19.5 Continental HDE all the way around. They are the stock tires from Ford. They are mud and snow rates.
 

ExpoMike

Well-known member
From what I read, most 19.5" wheel/tire combos are for OTR trucks with very high weight. They are more for supporting the load than ride comfort. I have never used anything in the 19.5 (or big truck world) but my guess is you are going to be fighting a losing battle. Ride comfort from tires tends to be from having sidewall flex. 19.5" tires don't have much flex. Suspension tuning is really where ride comfort should be setup from. My buddy who was R&D manager at Bilstein showed me that. Just a change in shock tuning completely took a rough riding vehicle to being buttery smooth, with no other changes in anything else. Just changed shock valving. BTW, this was my vehicle he showed me on. :)
 

Srpat

Observer
You will want input from Java's F450 build. He has had a lot of changes made to try and make his Toyos a smoother ride off pavement. He hasn't had as much success as he would want due to the Toyos being about the only tire choice to carry the weight on a 19.5" rim. If you want comfort on road, the 19.5" rim is not going to provide it in any configuration of suspension, kelderman or otherwise.

I went with the DBL design setup. It was expensive. Very. But the ride is good and I notice no problems with an increase of ride height from 10'10" to 11'4". MPG was affected. Maybe 13 mpg to 11 mpg. And that is with the diesel and going fairly slow. It does have the coolness factor to it. And it is significantly more comfortable on road and off. My MPT 81s are balanced with centramatic wheel balancers, so not much of a problem there.

Option 1 is cheap and gives you single tires with a decent payload. Option 2 is a better way to go for what you want, but maybe not a good enough reason to spend that much money. Option 3 seems like you will be going down a rabbit hole trying to find a comfort level that won't be found.
 

Vampergt4

Member
From what I read, most 19.5" wheel/tire combos are for OTR trucks with very high weight. They are more for supporting the load than ride comfort. I have never used anything in the 19.5 (or big truck world) but my guess is you are going to be fighting a losing battle. Ride comfort from tires tends to be from having sidewall flex. 19.5" tires don't have much flex. Suspension tuning is really where ride comfort should be setup from. My buddy who was R&D manager at Bilstein showed me that. Just a change in shock tuning completely took a rough riding vehicle to being buttery smooth, with no other changes in anything else. Just changed shock valving. BTW, this was my vehicle he showed me on. :)
Great input, I was thinking about reaching out to Icon, Bilstein and others with my final weights and look at getting a set of custom shocks.
 

Vampergt4

Member
You will want input from Java's F450 build. He has had a lot of changes made to try and make his Toyos a smoother ride off pavement. He hasn't had as much success as he would want due to the Toyos being about the only tire choice to carry the weight on a 19.5" rim. If you want comfort on road, the 19.5" rim is not going to provide it in any configuration of suspension, kelderman or otherwise.

I went with the DBL design setup. It was expensive. Very. But the ride is good and I notice no problems with an increase of ride height from 10'10" to 11'4". MPG was affected. Maybe 13 mpg to 11 mpg. And that is with the diesel and going fairly slow. It does have the coolness factor to it. And it is significantly more comfortable on road and off. My MPT 81s are balanced with centramatic wheel balancers, so not much of a problem there.

Option 1 is cheap and gives you single tires with a decent payload. Option 2 is a better way to go for what you want, but maybe not a good enough reason to spend that much money. Option 3 seems like you will be going down a rabbit hole trying to find a comfort level that won't be found.
Thanks, I always seem to come back to the DBL option but I am concerned that the tires will wear quick as most of my driving will be on pave.
 

Srpat

Observer
Yeah, I am happy so far with my setup. It was mediocre customer service with DBL design, but no issues so far other than the balance beads they put in the tires that caused a slight shuddering between 40 and 60 mph. I cant speak to premature wear. I have put maybe 2,000 miles on them. You can find posts on how great the mpt81s are and posts on how terrible they are, so good luck. But if your goal is comfort, any of the 20" custom rim choices will be the most important step to get it.
 

OverlandFT

Well-known member
I had the Toyo M608z tires in 225/70r19.5 and really hated them. They would catch the road and pull me in different directions randomly. Also, they did cause a sway feeling that made a very white knuckle experience. Those tires came with my truck and I used them for 500 miles before swapping to super singles. I went with Stazworks 20" with Pirelli PS22 335/80R20 and the ride/stability is much improved. They're smooth on the hwy and no louder than the Toyos. I only have about 2K miles on them though.

Honestly it's hard to recommend a 41" tire for 20K miles of mostly hwy. How heavy is your rig? I didn't have much option considering my truck is a Ram 5500 with a steel box. I remember there was someone in CO that built a truck camper and used 4,000 rated light truck tires. The tires would wear faster, but easily replaced at a tire shop and would be a cheaper setup overall. I'll see if I can find more info on that camper, because I don't remember the chassis size...
 

Vampergt4

Member
I had the Toyo M608z tires in 225/70r19.5 and really hated them. They would catch the road and pull me in different directions randomly. Also, they did cause a sway feeling that made a very white knuckle experience. Those tires came with my truck and I used them for 500 miles before swapping to super singles. I went with Stazworks 20" with Pirelli PS22 335/80R20 and the ride/stability is much improved. They're smooth on the hwy and no louder than the Toyos. I only have about 2K miles on them though.

Honestly it's hard to recommend a 41" tire for 20K miles of mostly hwy. How heavy is your rig? I didn't have much option considering my truck is a Ram 5500 with a steel box. I remember there was someone in CO that built a truck camper and used 4,000 rated light truck tires. The tires would wear faster, but easily replaced at a tire shop and would be a cheaper setup overall. I'll see if I can find more info on that camper, because I don't remember the chassis size...
Thanks for the reply. The chassis is a 2019 F550 4x4 and by the time I have all my mods done and stuff loaded, I will probably be close to 16k lbs.
 

OverlandFT

Well-known member
Ok, your truck weight definitely rules out the light truck tire suggestion (long shot anyways). Me personally, I would go for the super single setup and give your rig more capability for the far northern and southern roads. Like I said before, it's not an ideal highway setup, but definitely more versatile. The roads in Mexico alone can be terrible and would be more comfortable with the larger tires / super singles. As far as the driving quality concern, if MPT81s are too harsh, consider a less aggressive tire like the Goodyear G275 MSA or Pirelli PS22. Lastly, if you go this route, have a plan for where you're going to mount the heavy spare tire and how it will be mounted/dismounted from that location.
 
Forgive me if I have already said this in this thread:
If you go with the 335s, in addition to the secure mounting of the spare, try to figure out a place to store a (second) unmounted tire. 20” MPTs of any brand don’t grow on trees, and the vast majority of tire dealers in or out of North America will look at you like you’re on hallucinogens or from another planet if you ask them to quickly come up with one.
 

Vampergt4

Member
Forgive me if I have already said this in this thread:
If you go with the 335s, in addition to the secure mounting of the spare, try to figure out a place to store a (second) unmounted tire. 20” MPTs of any brand don’t grow on trees, and the vast majority of tire dealers in or out of North America will look at you like you’re on hallucinogens or from another planet if you ask them to quickly come up with one.
Correct, the tour guide to South America is recommending 2 spares. I was thinking of having 1 mounted and one loose.
 

Vampergt4

Member
So I have decided to stick with the 19.5 stock wheels and tire size, just can't justify spending 12k for DBL set up and end up with worse MPG and short tire life for this trip. Will be adding Sumosprings front/rear and replacing the OEM shocks. Now just need to decide on which shocks, I am considering either Fox or Bilstein. I've read the Fox and more off-road focused and Bilstein are move for on road. Anyone know of anyone doing custom shock valving or a better option. Thanks
 

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