I know the Fx4 package has skid plates for anyone who wants to go "off-roading" in a big King Cab truck!!! LOL Anyhow I bought my 2020 new in 2020 off the dealer lot. It came with the FX4 package. Great truck, hauls my 5 th wheeler great BUT empty it rides like an empty dump truck!! Some exaggeration but seriously it's the hardest riding truck I have ever owned....and at mid 70'2..thats a lot! half ton, 3.4 ton, one ton, single wheel, dually, you name it. My question, I have heard the FX4 shocks are stiffer than the 4X4 package. My dealer beats around the bush when I ask them. A friend has an F-350 but not the ZX4 package and rides like a dream. Can anyone verify if the FX4 shocks are stiffer than the 4X4, thanks. P.S. Tires are load Range E so I expect them to be stiff. Max cold air rated 80. Not towing I run 55-80 AP and it helps....a little but not much!

 

Both the standard and FX4 shocks are kind of crappy, go buy some new better shocks and enjoy the ride!

 

I can't verify the difference between the two but I do own an SD with FX4 and never found it to be as you describe. I have replaced the rear shocks with aftermarket mono tube shocks that are firmer and still don't find it to be overly firm. I doubt the FX4 shocks are much different than the standard 4x4 shocks and don't think the stiffness you are experiencing is shock related unless they have failed in some way.

When unloaded I would air down the rear much lower than that. I run 55 front and 50 rear.

 

I am curious. Maybe a stupid question, but how bad are the OEM shocks? In what way, over dampened? under dampened? fades easy? I am contemplating replacing my 21's FX4 shocks for a "better ride". At times and especially while driving at slower speeds it feels like the truck has no front suspension movement at all. Of course the lowered ride height (of MY 2020+) appears to have reduced up travel, and the sway bar in my opinion is way too aggressive.

 

Do you have the camper certification? Or plow package? I have the camper certification and mine rides extremely firm. I'm not complaining, but it is firm.

 

the fx4 shocks are supposed to be "offroad tuned" but no one has ever shown its any different than regular 4wd shocks.
when not towing you can get away with running 50 front and 45 rear in air pressue, that will help a ton in the ride. check here

https://tirepressure.org/lt275-65r18

when not loaded, the whole trucks weighs about 7000-8000 lbs depending on engine and cab size, 50psi can support 5000lbs per axle with two tires, so at most the rear axle weighs about 3500 lbs empty, no need to run anything more than 45psi empty rear and 50 front.

If you have a high payload, plow, or camper package then the stiffer springs are part of the culprit too.

My stock F250 with FX4 running 50psi front and 45psi rear when not loaded rides like a 1/2 ton and still extremely stable down the road, it has the standard 10k GVWR rating and ~2800 lb payload

 

Just re-read my original post. I run 55-60 Max AP no 55-80 when not towing 5th wheel. I consider my tire wear to be average to good. Have basically 38,000 miles and some would run them at least another 10,000. I'm kind of a tire nut and probably won't run the much more, maybe another 5,000. I do know the Wrangler Kevlar tires have very firm side walls. Rated at 80 MAX cold I only Ron 70 MAX with 2,500+ pin weight and truck settles only 2 1/2-3", no tire squat. I'll try 45/bs rear empty for a while and watch tire wear. General answer. No truck does not have the camper package or plow package.

 

sounds good to be, thats why I brought the subject up but when you say better shocks what do you recommend?? Not being a wise guy but are you speaking from experience??

 

Different generation super duty family platform, but on my ‘05 Excursion I like the Rancho 9000XLs much better than the OEM shocks.

 

As mentioned, nothing special about the FX4 shocks (or the package). They are just as bad as the standard shocks. I definitely wouldn’t pay for a set aftermarket. There has been plenty of threads about failures on both of them so many folks just upgrade to something better. Bilsteins, Fox and Ranchos are the popular options for stock trucks. I myself went with the Bilstein 5100’s on all 4 corners and I swapped the OEM steering stabilizer out for a Bilstein 5100 stabilizer as well. As far as ride, mine has the beefiest front and rear suspension you can put on a stock SRW Super Duty, as well as a rear sway bar. It rides like a truck, but I find it rather comfortable considering it’s a truck made to carry heavy loads. Of course it doesn’t ride like an F150, but if it did it wouldn’t be able to perform like a Super Duty. Like others, I do air down to mid 50’s when empty and that helps a lot too…

 

I just changed my FX shocks to Rancho 9000XLs at 57K. The difference is very noticeable. In addition, I lowered pressure to 55F and 48R on Falken tires. Combined together the ride is much much better.

 

One thing I haven't seen mentioned by those who air down into the 50's. Do you get the low tire pressure warning? I once adjusted the tire pressure warning threshold in on a previous Super Duty with FORScan. I don't recall doing it on my current truck. I normally run 5 psi or so below the recommended and it doesn't set off the TPMS.

 

I ordered my 2020 without the FX4 package mainly to gain some payload capacity. I'm not sure if it was enough to matter though. Anyway, before it came in I had a set of Fox 2.0 shocks waiting for it. The only driving it got on the stock shocks was about 40 miles. I really can't tell you if there was a difference in ride with the shock change but I do know that my long bed rides very comfortably for a big truck. We have taken it on several long trips without the fifth wheel behind it. Three of those trips were over 1600 miles each. My wife is pretty particular when it comes to comfort in a vehicle and she has no complaints if I say let's take the truck instead of her Subaru Ascent. I never adjust the tire pressure.

 

As I stated I have owned many trucks..1/2 ton to 1 ton. I do not expect it to fire like an F-150! Also the ride is not due to "shock failure" as many have suggested as ithe ride hasn't;t changed since it was new. Thanks for the suggestion for the 5100's! Although I wonder what the steering stabilizer has to do with ride quality. I'm not having the "death wobble" people speak of. Also my friends F-350, which has heavier suspension than my F-25 rides great! Differance being the FX4 package. I appreciate everyones input but the question of wether they are stiffer than the 4X4 shocks, again no one really seems to know. I really have no desire to "put on stock SRW Super Duty shock" if no one really knows if they're any different than the FX4 shocks. Again thanks for the input.

 

Yes, the lower rear tire pressure sets off the warning light. I think maybe the rear tire warning threshold is 55 on my F250, and below that gives you the warning. Change threshold with forscan, like you wrote.