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I own a 2016 2500 PM high roof 159 WB stone stock. Has anyone added a rear sway bar? I was told that would help with the Van swaying in windy conditions. Any advice would be appreciated.
 

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It is available and not expensive. Rear sway bars will reduce the suspension’s ability to absorb the shock from one rear tire without transferring it to the other rear tire, as well as reduce sway. This is already a very stable vehicle as MsNomer is saying, so unless you have a lot of weight up high I doubt you are going to like the effect. If you think your van sways then try it and report back. The 3500 van has one as a factory fitment, and I don’t recall complaints.
See: https://www.amazon.com/Hellwig-7254...192849&sr=8-1&keywords=ram+promaster+sway+bar
 

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There's no need for a sway bar on the PM unless you plan on pushing its load capacity to it's limits.


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To a crosswind, a van is a sail. The ProMaster already has better stability than most, because Fiat paid attention in the wind tunnel when designing these, and because of the front wheel drive.

A rear sway bar is very low on the list of things that would affect crosswind stability.
 

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I installed airtabs on my van, it helped slightly with crosswinds. It also increased fuel mileage some and keeps the rear of the van a little cleaner.
 

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I installed airtabs on my van, it helped slightly with crosswinds. It also increased fuel mileage some and keeps the rear of the van a little cleaner.
I'm considering adding Airtabs as well, so thank you for the report. Can you please post some pics?

Cheers,

Dave
 

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I have to say I am a skeptic on both counts. If it were that simple wouldn't EVERY trucker have them? Or the automakers could put a little air disturbance wave in the body? This van has amazing airflow management already. I wonder if some stuck-on plastic dart can help? You both do it and let us know. Find a way to measure it please because most of what I read about them sounds like placebo effect. I don`t have those deer whistles on my vehicles either. LOL. NASA who knows a bit about aerodynamics retrofitted an 18 wheeler to improve aero mileage and did not use them, as far as I can tell. They opted for a tail extension which we are seeing on long distance trucks. I`d wonder how long it would take to save enough fuel to pay for them at $250? Let us know. Thanks.
 

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I'm skeptical of the air-tabs, too, although there are a few vehicles that have something of this sort - I believe there is a version of the Mitsubishi Evo that had them, I know I've seen them in an application that looked OEM. Problem is that just because the OEM puts them on there, doesn't mean they are effective ... they do things for styling, too (a lot of spoilers fall into this category). I tend to suspect that optimum placement, IF they accomplish anything at all, would have to be fine-tuned in a wind tunnel for each different application, and that only some body shapes would benefit. The Evo has a sloping roofline and the "flow disturbers" are on the roof just above the rear window. A van has a rather enormous flow-disturber in the shape of a sharply cut-off roofline. On the other hand, it's unlikely that they will do anything "bad".

Air dams work. The underside of most vehicles is extremely "dirty" aerodynamically, and up to a point, it's better to divert air around the outside of the vehicle rather than letting it get underneath. Look at newer GM vehicles, in particular. Manufacturers can have their own reasons for NOT putting on big air dams - styling, they can be prone to damage, may not be worth the cost in specific applications, etc. Air dams are most effective when combined with side skirts that stop air from getting back in from the sides. But most people don't want to drive a van or truck that scrapes the ground on every kerb, so there is a trade-off involved. (Look at the skirts they are putting on tractor-trailer rigs now. Same reasoning.)

Grill-blocks work IF you can spare the airflow through the radiator. Again, the radiator and the engine compartment are aerodynamically "dirty" and it's better to send this flow around the outside ... BUT ... you obviously need a certain amount of airflow for engine cooling, air conditioning condenser performance, etc.

This discussion prompted me just now to go take a few pictures of what I did to mine. New thread on aero tweaks coming up in a few minutes ...
 

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the factory bar on the 3500 routes in front of the rear axle beam. Doesn't the aftermarket ones go to the rear? My factory bar measures just a tick over 20mm. So far the only time I have noticed any sway when passing a semi is when the van was completely empty and I was towing about 3K pounds, in a corner, lift throttle. That was the only "Oh SHEET!" experience. After the initial adrenalin rush, it collected itself and got on thru the corner. Other than that it's mostly felt about the same as driving any family sedan or minivan in a cross wind. There is something to be noticed but nothing much white knuckle about it. Mine is a gas 3500 hi top, extended

Will look a the aero tweaks thread. I have looked on ecomodder and not really sure I have seen a dedicated Promaster thread. Think it has been mentioned tho. I've wondered about a lower front air dam along with long running boards helping aero. Belly pan between the running boards?? The only thing I'm not 100% happy with is the mpg with my gasser. But then, I do know it is perfectly stable at 80+. Sometimes my foot is made of tungsten, not lead... Accelerates and stops better than my ole 97 suburban tow/heavy lift vehicle, getting same or better mpg, all while holding LOTS more.
 

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I hear you. I opted for the diesel because I had heard such good things about its ability to pull and not shift down etc. Lots of early estimates on what it would get for mileage suggested the payoff for the $4,000 extra I paid would essentially never happen. Predictions of 22-23 mpg. In reality it is easy to get 26 or a bit more, a bonus to me and a payoff of about 100K miles. For my van the high 60’s are the point where it begins to have aerodynamic drag sufficient to really affect mileage. I try to stay in the mid 60s as I am frugal (cheap is such a dirty word). Air resistance increases as the cube of the speed all else being held constant, so the drag rises very fast. If thirty produces a certain drag= “D" then 60 produces 8D! Going from 60 to 80 DOUBLES the air resistance. The best aero tweak is to slow down even a couple of miles per hour! 78 instead of 80 should save over 7% fuel! Perhaps more than the airtabs even if they do work. At the end of 10 hours of driving you would have gone 20 miles less in nearly 800 miles! Our right foot may be the best fuel saver we have.
 

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there are some pics on my thread "I installed air tabs" on the promaster picture forum. I cant seem to load any of my new ones tonight
 
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