Bottom line why waste money on a truck that will never ride real soft. Simply trade for a lighter duty truck. World of difference in ride.

 

This is my situation. I won't ever use this truck to it's capacities, having gotten out of our rv. I'm ok with this with the caveat that I need to improve the non towing/lightly loaded ride, which will constitute 100% of my future use.

I'll swallow the size and mileage of this truck in exchange for the room, comfort, and storage as long as I can get this suspension dialed in.

 

You are very right - on 17-18" wheels with a tall profile (75 section or greater), probably somewhere about a 1/3rd of your suspension travel in high speed bumps will come through tire deflection at normal operating pressures. You can easily increase this (and effectively soften up your suspension) by dropping tire pressures. Obviously the TPMS may have to be recalibrated/ignored, you may get slightly worse milage on the hwy, and if you are carrying a heavy load you will need to bump the rear pressures back up.

I personally think Rim's need to be no larger than to clear the brake callipers (even if you do lose some stability). I like the look of the 20's on my truck (they came with it), but when it comes to replace tires, I'm thinking hard about a 17" steel wheel/tire combo.

 

I agree with BigF350 on the tire/rim combo, and/or going to a half ton.

 

I understand not everyone will enjoy the ride on road but I'm not buying it for its on road performance, I'm going Carli for their off road performance because I drive a lot of bad gravel roads. The suspension on my truck rides like crap already so it can't get any worse, and I already planned on lifting my truck so why not get a kit that's going to ride better than any skyjacker, bds, pro comp ect.? Also I'm not planning on running anything bigger than an 18" rim, most likely I'm going to wait till my current tires wear out and then replace them with some 35x12.5r17s or 37s on 17s. So I'm sure the ride may not be as impressive as most people think but off road it's going to be better than almost any other out of the box system.

 

Aha! Finally a voice of reason!

I have always said just that, the only reason for larger diameter wheels is to clear larger brakes. ( Which I strongly suggest. ) Other than that you are just driving up the price of your tires which are already stratospheric. Other than that you have just fallen into the "style trap."

 

Quote from BigF350:

You are very right - on 17-18" wheels with a tall profile (75 section or greater), probably somewhere about a 1/3rd of your suspension travel in high speed bumps will come through tire deflection at normal operating pressures. You can easily increase this (and effectively soften up your suspension) by dropping tire pressures. Obviously the TPMS may have to be recalibrated/ignored, you may get slightly worse milage on the hwy, and if you are carrying a heavy load you will need to bump the rear pressures back up.

I personally think Rim's need to be no larger than to clear the brake callipers (even if you do lose some stability). I like the look of the 20's on my truck (they came with it), but when it comes to replace tires, I'm thinking hard about a 17" steel wheel/tire combo.

Quote from Randy_270:

I understand not everyone will enjoy the ride on road but I'm not buying it for its on road performance, I'm going Carli for their off road performance because I drive a lot of bad gravel roads. The suspension on my truck rides like crap already so it can't get any worse, and I already planned on lifting my truck so why not get a kit that's going to ride better than any skyjacker, bds, pro comp ect.? Also I'm not planning on running anything bigger than an 18" rim, most likely I'm going to wait till my current tires wear out and then replace them with some 35x12.5r17s or 37s on 17s. So I'm sure the ride may not be as impressive as most people think but off road it's going to be better than almost any other out of the box system.

Quote from Bdox:

Aha! Finally a voice of reason!

I have always said just that, the only reason for larger diameter wheels is to clear larger brakes. ( Which I strongly suggest. ) Other than that you are just driving up the price of your tires which are already stratospheric. Other than that you have just fallen into the "style trap."

I agree again. I would run a 17" wheel but most aftermarket wheels won't fit around the newer 2013 caliper. There are a couple that will but have a backspacing or offset that I don't want. That is why I went with an 18" wheel. I have read on these forums that a load range D tire is advantageous for ride quality. I disagree as with most tires when it is time to pull a heavy load/boat/5er you can't safely air the tires up enough. Even if you do and then get into an accident it could potentially be a problem.

I have accidentally said the "R" word (Raptor) on a Ford forum that I am obviously new to and just want to say I think they are awesome. The reason I bring up the Raptor is because it is THE BEST half ton out there for off of the street performance. I have 2 friends that have them. They are great trucks especially how my buddies have theirs set up with aftermarket suspensions ($$) and one even has a roots style blower($$$$). They are completely capable off road and very nice on the highway. Here's the but. Buuuut...my buddy with the big boy Raptor (blower and wild suspension) also has a '06 F-150 2WD extended cab with a 5.4 (blown) and a Camburg suspension kit (not a true pre-runner in case that was what y'all we're thinking) that used to be the Camburg Inc.'s shop truck. That thing, while not as fast as his blown Raptor, can take the big stuff way better that his Raptor with 4-5k in aftermarket suspension. Also my aforementioned '07 Dodge with the KORE kit, Smarty, and a Gorend tranny, ran circles around both Raptors off road, hung with the F-150, and was almost 2000lbs heavier. I say that because I keep reading comments from real truck guys on good forums that these 8500lb Superdutys cannot be expected to ride like a half ton. They can, and depending on the build, do perform better in some cases but you have to be willing to take some info we all know/knew about trucks and chunk it out of the window. I know the Commuter kit I ordered from Carli is different from what I just mentioned. But all I have to do is buy King's (direct replacement) and full progressive leaf packs to replace everything out back and I'm back to the kind of performance I was getting from my Dodges minus the speed (not from the motor but the 10k i had in my Cummins not counting tranny) which is better that any stock "R" word. Last thing...I'm no Dodge or Ford fanboy. I just like what works, which is why I don't like chevy:-(0)

 

Yeah but for example my D-range tires are rated single 3750lbs at 50PSI... it doesn't need to be at 80PSI to get that rating. Even at that load rating you would be overloading every other part of the truck before the tires, assuming the weight is evenly balanced across the 4 tires of the vehicle.

I went through this thought process when specifying my tires which are 38 on 18s, there are few or no load range E options at that size, but then I realized ply rating doesn't matter when you can achieve the same load rating at a lower inflation pressure. Furthermore with my usage this truck will never meet its GVWR or GCWR.

 

That's true, but the load range of the tire means very little when it comes to ride quality. People like to talk of stiffer sidewalls, but they forget that the rubber sidewalls aren't holding up the truck. It's the air inside, and higher load range tires permit more air pressure.

 

I was talking about off road performance when I wrote this post.. Carli isn't all that its cracked up to be.. I drive more gravel road than most people I know. I guide all over the province, I run lease roads, I use my truck ! Drive one with a Carli before you buy.. That's all I suggested.

 

Does anybody know for sure if I can fit a 17" wheel over the calipers?

I'm going to snoop around for a set if I can to replace my 20" KR wheels.

I know when I went up to a 20" on my 2006 the ride quality dropped noticeably.

Thanks,
Kevin.

 

17" are the smallest that fit (they come standard on some models) on all 05+ trucks.

 

Thank you.

 

Wouldn't less air pressure cause the tire to wear funny. I thought I remembered from shop class in school that if pressure was to high the middle would wear faster and if tok low the outer edges would wear.

Also for a softer ride, why not get a softer front spring and remove a leaf or 2 from the rear pack.

 

It can, if you lower it too much and do lots of hwy work, gravel road use you won't.
The best way to check on road use is to run a chalk line across the tire tread, drive a hundred feet or so, and see if it wears across the entire line.

In my experience, Super Duties have a wide band of "operating pressure" with the stiff sidewalls of E range tires.