rough road commuter...again...

4" wide cracks? You need big diameter and lots of sidewall. 

I'm voting Raptor. LOL! Big squishy tires and tons of suspension travel. 

Problem with using trucks or large vehicles that can carry a heavy payload is that their suspension has to be able to deal with it, so they're probably going to lose some compliance when lightly loaded. IIRC Ottawa found this with his cop Tahoe after the P71, but maybe he'll chime in.

In reply to Keith Tanner :

That can definitely be a problem.  But outright stiffness is far from the only issue in ride quality.  Good damping, especially with attention paid to low speed compression damping (so the suspension can start to move easily enough on small impacts), and low unsprung weight (relative to total weight) matter a lot.  Up to a point, high spring rates can still ride well if everything else is good.

Keith Tanner said:

Problem with using trucks or large vehicles that can carry a heavy payload is that their suspension has to be able to deal with it, so they're probably going to lose some compliance when lightly loaded. IIRC Ottawa found this with his cop Tahoe after the P71, but maybe he'll chime in.

Tire pressure helps a lot there too. Most trucks are delivered new with very high pressures with full load and towing in mind. Lower the pressures when not loaded.

In reply to rslifkin :

I have a street Miata with 750 lb front springs and shocks I valved myself :) I didn't specify just outright stiffness, the damping is designed to control a vehicle that can vary in weight by thousands of pounds. In order to make it work ok with a wide range of operating conditions, it will never work really well in any.

I run 45 psi in the rear of my Dodge 2500 when it's empty and 60 psi (or 70? I forget) when it's loaded, as per manufacturer recommendations - that's even baked into the TPMS monitors, you can tell if it you're in light or heavy load mode. I'm very familiar with the effect those pressures have on ride quality. Also familiar with how it rides with the airbags pumped up and thus a higher rear spring rate - you do not want to drive that empty if you can avoid it. But you're still dealing with tires that have a very high load rating and thus a stiff sidewall. A 4000 lb vehicle with a GVWR of 5500 lbs is going to have a very different tire on it than a 5500 lb vehicle with a GVWR of 7500.

In reply to Puddy46 :

Nope. It's the cheapo Sport.

In reply to bmw88rider :

Our E350 was a magic carpet at the time,  but honestly I would go with the Jeep. The Merc wins, but fails with many more dealer visits. 

Tk8398 said:

I'd try to find a W126 or W140 Mercedes.

This^  Getting pretty old now but nothing else rides like one.  

In reply to Keith Tanner :

Yeah, once you get beyond the 1/2 ton trucks and SUVs, the game changes a bit.  The loads carried start to become much larger relative to the empty weight, tires get stiffer, etc.  But most of the 1/2 ton trucks and SUVs ride quite well despite the not so good empty ride of the 3/4 ton and up stuff. 

Of course, I'm also of the opinion that many non-performance cars had their shocks valved by an idiot, which makes many of them ride pretty badly for no reason. 

In reply to Shadeux :

Well color me impressed.   My Gladiator rides nice as well, but it's a Rubicon, so I expect a bit of stiffness.  Sounds like whatever flavor you like is worth looking into.  

Interesting that the Jeeps show up so much here - at least the highways I've driven them on that have "rollers" in them, they seem very wallowy like the compression damping in particular was made very soft to compensate for the unsprung weight of those solid axles or something. May not have had stock shocks though.

I'm going to throw another vote out there for older Mercedes products. Even the W124 impressed me at a slightly less complex/cheaper level. My E34 525iT was also one of the smoothest daily drivers I've had; I loved that car and would have another if I didn't have so many E30s in my driveway. That era of Mercedes and BMW definitely has a good balance of suspension travel and tire sidewall. I remember being impressed by the isolation of the first gen Lexus LS as well.

In reply to rslifkin :

That 5500 curb weight/7500 GVWR example is a Tahoe :) It's gotta be set up to deal with nearly an ND Miata worth of weight variation. I agree that factory valving is, in large part, terrible. Even performance cars, like that 997 Porsche I was driving a month ago.

Our WJ Grand Cherokee rides reasonably well. It's no '60s Cadillac but it's sure a lot better than something like a "sporty" BMW X1. It's fundamentally handicapped compared to a well-tuned sedan so while it can be made to work, the same level of care will make a car work better as long as the car isn't compromised on sidewall or travel.

Our E39 works pretty well, but when I got it the bushings were toasty and the shocks were done. You've gotta evaluate these things in full health, not ragged. Even a set of old tires can have quite an effect.

Keith Tanner said:

In reply to rslifkin :

That 5500 curb weight/7500 GVWR example is a Tahoe :) It's gotta be set up to deal with nearly an ND Miata worth of weight variation. I agree that factory valving is, in large part, terrible. Even performance cars, like that 997 Porsche I was driving a month ago.

Our WJ Grand Cherokee rides reasonably well. It's no '60s Cadillac but it's sure a lot better than something like a "sporty" BMW X1. It's fundamentally handicapped compared to a well-tuned sedan so while it can be made to work, the same level of care will make a car work better as long as the car isn't compromised on sidewall or travel.

Our E39 works pretty well, but when I got it the bushings were toasty and the shocks were done. You've gotta evaluate these things in full health, not ragged. Even a set of old tires can have quite an effect.

I don't know much about tire construction but real life experience I have found the same. tires that are heavier duty ride worse when unloaded. Is it due to more plies? Stiffer sidewalls?

I'm thinking that what I'm looking for doesn't exist, that's tall aspect ratio in a 16" rim but low load rating (soft carcass) and a smooth street tread pattern. I think naturally as you go to larger diameter tires, they are only available in AT styles or HD commercial style. 

The other route is to try and upgrade the van's suspension. But I'm running into the issue of no aftermarket parts or no quality suspension parts even available. My lower A arms, front struts, swaybar links, and rear shocks have all been recently redone. The only thing left is to start replacing bushings which is a lot of work. I have good quality continental winter tires. Maybe I should just start airing them down 5psi on purpose. 

Years in the car business. Probably owned a 100. So many laps that my children may never pay off the parts bills... Still drive lots of miles.  I pride myself on smoooooooth and safe like a guy that has had a motor license for over 40 years... And the absolute smoothest ride EVER was in a female Chauffer driven Lincoln Town Car.      Lincoln Town Car (and that driver) for the win x 1 million.  

rslifkin said:

My E38 (740i sport) has 18" wheels and the factory sport springs.  I'd say it rides well on roads like that, but not great. 

Yeah, the 740iL (long wheelbase, non-sport) will ride a lot better.