Windy driving conditions

[eason]

Hi. I have a 2015 airstream extended grand tour and I love it. My question is about driving- on a recent trip we had crosswinds for hours which created white knuckled driving. I'd go thru an underpass and have to hold the steering wheel one way, come out of the underpass and quickly have to jerk it the other way. I would appreciate any suggestions to solve this problem without having to go to an air system- example: any away bars that may work or shocks that might work.
P.S.- also i tow a 2015 jeep rubicon 4 door which can feel at times like the tail wagging the dog.
Thanks for any help.

[Boxster1971]

How fast are you driving with heavy cross-winds? These vans are a big sail area and the best solution I can offer from experience is to slow down a bit to about 55-60 in high cross-winds.

That Jeep Rubicon is just another box behind you adding to the problem.

- - Mike
2013 Lounge EXT on 2012 Sprinter

[DaveFL]

I found my air bags for the front springs, tire pressures, and speed amplified wind movements. In previous van mh I solved it by installing a steering damper or shock absorber. Looking at the sprinter profile I would suggest removing all weight from high cabinets, filling the water tanks. Maybe Protag as an engineer can offer better solutions.

[UKDUDE]

It's a problem with all Sprinters, and I think I remember my local dealer telling me they are installing some technical wizardry to reduce the effects of cross winds. Applying braking to the diagonally opposite rear wheel, or something like that. More to go wrong in my opinion. Just drive slower.


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[DaveFL]

Just noticed it is your first post, Welcome to the land of information.

[Ron_CA]

Let me guess...New Mexico or Texas?

I have experienced major winds for hundreds of miles and it definitely takes a toll on the driver. Like others have said, just slow down a bit and you should be fine.

[Protagonist]

Originally Posted by eason

P.S.- also i tow a 2015 jeep rubicon 4 door which can feel at times like the tail wagging the dog.

Okay, let's see… A Jeep Wrangler Unlimited Rubicon has a GVWR of 5700 pounds, in excess of a Grand Tour's towing capacity. The curb weight is 4500 pounds, so if you're carrying any cargo more than than a full tank of fuel in it (fuel is considered part of curb weight) you're pushing the limit of your Grand Tour's towing capacity.

The Jeep has a very boxy shape, and is long enough that it doesn't fit entirely within your Interstate's slipstream. Meaning that the rear end of the Jeep is always in turbulent air. That would certainly contribute to the "tail wagging the dog" syndrome you mentioned.

One thing that should help is to get a front-end alignment done on the Grand Tour, especially if you haven't done one since buying the van. When Airstream bought the vans from Mercedes, the empty vans had the correct alignment. But that's before Airstream added a bunch of weight that may or may not be a balanced load. And Airstream does not do alignments on the vans they sell. Since a bad alignment can contribute to directional instability, getting the van realigned is pretty much the first step toward a fix, and is cheaper than other suspension improvements you could try.

From a safety standpoint, there are two "best practices" for high crosswind situations. (1) Park it and wait for the wind to die down; and (2) if you have a second driver with you, unhitch and drive each vehicle separately until the winds die down. Each vehicle by itself will be better-behaved in a crosswind than will the combination hitched together.

Given the shape of a Jeep and the shape of a Sprinter, each one will catch crosswinds more strongly at the rear of the vehicle than at the front, and they will both have a tendency to want to weathervane (point up into the wind), meaning the rear will want to veer farther than the front and steering corrections are not too difficult or scary because the van will actually help you steer in the direction you want to go.

Pin the two vehicles together at the towbar and it no longer becomes possible to predict how the combination will react to crosswinds without putting them into a wind tunnel and/or on a skidpad, but I'm thinking the Jeep will be more stable than the Sprinter because of having no overhangs to speak of, and having less surface area to catch the wind. That means the rear of the van will veer less than the front if both vehicles catch a crosswind (the exact opposite of weathervaning) as the Jeep serves as an anchor, and you need more steering correction to stay in your lane; the van will have a tendency to fight your steering corrections.

Ballasting by filling the fluid tanks and emptying the overhead lockers will not help much, except to reduce the tendency of the van to roll over as it veers. Suspension improvements other than the front-end alignment are the same. If you upgrade the rear suspension the van will not rock or lean and much as it veers, but that won't keep a crosswind from making the van veer out of its lane because you're still at the mercy of the van's surface area acting as a sail.

I have not crunched numbers on this, so everything I said is an opinion, not an analysis. If anyone out there has a different interpretation, I'd be glad to read it.

[eason]

Thanks for the information. On the real windy trip I wasn't pulling the jeep but I was averaging 65 mph. Slowing down would help I'm sure. I appreciate all of the input. When towing the jeep in optimal conditions it still feels like it wants to wander on me. Is that normal? Has anyone else found ways to correct this? I use a blue ox tow bar 4 wheels down towing.

[InterBlog]

A picture tells a thousand words. Here's one of Bastrop Texas taken earlier this year. See the orientation of that jumbo flag relative to the highway? This was a 45 mph max trip for me, all the way back to Houston. No way to deal with cross winds like that, except to drive slowly.

Since that time, we have replaced our shocks and sway bar, which has improved our performance envelope somewhat. But still, we don't pretend it's a car.

[c21]

Wind has been a consideration for me although a minor one along with the sway when angling out of a driveway. I am having the Koni FSD rears installed as I write this. We just did a week long trek to San Diego (320 miles each way) and averaged 19.6 mpg down and 20.0 comming home. (63mph all the way) Needless to say I am very please with the mileage.

[Mjgman]

We hit really bad crosswind going through Kansas.. The wind was so bad it set off the ESP (electronic stability program).. I thought great, we are in the middle of no where with this alert flashing on the dash.. We called a dealer in Denver and she said that it would reset as soon as we turned it off.. She said many people pull into the dealership late at night and spend the night only to find out in the morning all they needed to do was get of the windy condition and reset the system..

[joemikeb]

A set of Koni shocks and struts did wonders for the cross wind handling of my 2013 AI. But sudden heavy gusts can still be surprising and/or challenging.

[c21]

So, I picked up my AI with the new Koni FSD's and intentionally angled across the driveway and into the street and what an improvement. Very little rocking compared to experience with the stock shocks. It also cornered noticeably flatter. Very worthwhile investment.

[LB_3]

The beefier sway bar works wonders to reduce sway on the highway. But on unpaved roads it actually magnifies the ocilations making some park roads a 5 or 10 mph affair.

[MILATV]

2014 Int Ext in high winds at 75 mph for about 100 miles across panhandle caused cruise to stop working and ESP to disengage (tech told me the varied inputs from the vehicle caused the computer to malfunction).

When i pulled in for fuel I shut down van to fuel, restarted engine 3-4 min later and all was good.

[BurntAsphalt]

My 2011 AI 22' rig was very susceptible to windy conditions. Every time I drove on the interstate in 15mph and higher winds, the ESP Visit Workshop message would show after the first gust. The first time it happened I was driving home from the dealership. The gust caught me by surprise and caused an acute case of buyer's remorse as I was blown into the passing lane. I wasted an hour at a truck stop Googling the error message and disassembled the brake light switch with an ink pen, which was one of the recommendations. It appeared to be functional, so in frustration, I started the Bus and lo and behold, the message disappeared!
After that episode I made it my life's mission to improve the handling in windy conditions. (I lead a very shallow life). First modification was front and rear SumoSprings which had no effect on wind but did improve body roll during cornering. Second mod was Koni Reds (100% dampened) in front and Koni FSDs in the rear. This produced dramatic results but high wind gust still kicked out the ESP. Third mod was Roadmaster anti-sway bar just installed today. Drove it in 15mph winds today and I wouldn't have known it was windy except for the fully extended flags along the highway. I can't wait for the next blustery day to see how much wind the Bus can take. The rear seat ride is still intolerable for adults but I don't plan on carrying passengers back there very often.

[Protagonist]

Originally Posted by BurntAsphalt

My 2011 AI 22' rig was very susceptible to windy conditions.

I wonder why our experiences were so different… My 2012 Interstate is nowhere near as sensitive to wind gusts. Even before installing the Koni shocks there has only been one time I was blown hard enough that I thought I would leave my lane, but I never did; my passenger-side tires crossed the rumble strip on the side of the road, but the driver's side wheels never left my lane. But that was scary enough because I was on a high-rise bridge on I-55 at the time.

And I've never had the ESP system konk out on me. Not yet, at least.

The windiest conditions I've encountered so far in my travels have been on US287 in the Texas panhandle. Which stands to reason judging from how wind-power turbines are cropping up like weeds all over that part of the country. You know it's really windy when the turbines stop spinning and go to full-feathering mode! But even then my Interstate was surprisingly well-behaved.

[iaqstuff]

Kansas winds bad. Texas panhandle winds bad. Navajo reservation winds terrible! ☺

[Nuvite-F]

It's always good to remember that aerodynamic forces are proportional to the square of the airspeed. For a ground vehicle the airspeed is the vector sum of the ground speed and the wind speed.

For example if you are driving 65 MPH with a 60 MPH crosswind the airspeed is close to 90 MPH. Slowing down a little helps, and slowing down a lot helps a lot.

A couple of years ago I went over the Blatnik Bridge between Superior, WI and Duluth, MN, (120 feet above the water) in crosswinds gusting to 65 MPH. No sweat--I just got in line with the semis, which were driving about 25 MPH.

[InterBlog]

Originally Posted by Nuvite-F

It's always good to remember that aerodynamic forces are proportional to the square of the airspeed. For a ground vehicle the airspeed is the vector sum of the ground speed and the wind speed.

....

The term "cross wind" is not precisely defined as it implies a range of scenarios, not just a perfect 90 degree wind situation. Empirically speaking, the Interstate is exquisitely sensitive to the *angle* of the wind. The absolute cross wind speed is only one variable in the equation (literally). A lower cross wind speed at a worse angle causes a bigger problem than a higher wind speed at a less consequential angle.

This is why, when I report to my husband how the Interstate is handling (I'm always the first driver of any given day), I always include words like "today" or "right now". As in, it's handling well right now, under the prevailing conditions.

It is humbling, to say the least, to get blown out of a lane of travel. There is one particular curve on Texas State Highway 6 between Houston and Waco where I know to slow down on general principle. If there's any significant wind, I know I'll transition through that worst-case angle, I'll catch the wind in a way that will amplify the forces associated with the curve itself, and I'll be catapulted out of the lane.