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Comfort Drive, A Steering Innovation

April 20, 2008 by Lug_Nut · 15 Comments  
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 Comfort Drive, what is it, and is it all they say that it is?  First, it is actually ColumnDrive, and was designed and built by the world leaders in hydraulic steering systems and electronic steering aids, TRW.   The name Comfort Drive is what it is termed by Newmar, the only motor home manufacturer that has to date been able to offer it.   This was the result of an exclusive arrangement for a given term between TRW, Spartan and Newmar.  It is believed that this contract will expire sometime in July of 2008.  For reference, going forward, I will use the term CD which is the initials for either Comfort Drive or ColumnDrive.

 

The CD product is an electronic steering aid that is located between the steering wheel and the steering gear.  It is not connected to, nor does it directly affect any portion of the hydraulic system.  It is a software-driven computerized device that utilizes an electro servo motor to react to user steering input, steering gear feedback and self centering predictability.  The steering input energy is substantially reduced requiring less force from the operator.  The needed input force is slightly increased as the vehicle’s speed increases, but still remains lighter than normally experienced.  More about this will follow a bit later.  Steering wheel kick from the road is virtually eliminated for the user and is totally handled by the CD.   Computing both the operator input and the steering gear feedback, the CD automatically predicts and corrects the steering center.  Once this is accomplished the steering weight does not favor either direction regardless of road slope or wind forces.

So, basically that’s what happens, but how does it feel to the operator?  Well, when I first drove a demo Essex in California in the spring of ‘06, I had mixed reactions.  The demonstration run was primarily through an urban area with speeds limited to 30 or 35 miles per hour.  The first thing that is really apparent is the super light feel of the steering, especially when the vehicle is stopped, or hardly moving.  There was little to no wind and the roads were relatively flat without much crown slope, therefore pretty well eliminating the need for the steering to self center.  Upon returning to the parking lot where the demo run started, I had the opportunity to turn and back it in a space between two other coaches.  This was a pleasant new experience.   I turned sharply as I backed toward the space.  Once the coach was nearly lined up with its parking place, I released the steering wheel.  It automatically tracked to center and guided the coach straight down an imaginary course line.  It was pretty impressive.  Even stopped I found the steering wheel would automatically turn to center if turned in either direction, even from a full hard over position, and released.

 

So, was it a must have after such a demonstration?  I my opinion, it was not.  It certainly was interesting, but I was not yet fully sold.  In some sense I wondered about such a steering, as it substantially reduced road feedback.     That is, assuming that in fact road surface feedback, is a good thing.  It must be, we’ve always had it, so it must be needed, right?  Well, as I later learned, may be we don’t need it.   In fact, perhaps it would be better not to have any steering feedback.  After all, what exactly am I really doing with the “feel of the road” feedback?   That sudden steering wheel kickback, as you cross an uneven section of road surface, may be well worth being rid of.

Well it seemed pretty good so I purchased a coach that came with this new innovation called Comfort Drive.  I soon found the answer to the feedback question. 

  While driving on an uneven road surface, as a result of a contractor doing some repaving,  the front tires met a multi-ridge pavement distortion at about 60 miles per hour.  This led to a quick coach body movement to the left and then back again.  No steering wheel pull was experienced using the CD during this event, and the coach sailed on without driver input or any noticeable change in lane position.  This was a far contrast to my previous coach, which, while it was an excellent driving motor home, steered about 8″ or so left to right when presented with the same challenge in similar circumstances with nearly identical tire deflection.   In analyzing it now, it would appear that the steering kickback felt in the standard non-CD equipped unit caused an unconscious reaction which led to instant driver input.  This, certainly in my case, and quite possibly others, displayed symptoms and results of over steer.

 

Over steer, seems to be the most common mistake of new CD drivers.  This is certainly not caused by steering gear feedback, but more than likely a reaction of the reduction thereof.  This may be amplified when a driver first drives a CD equipped unit.  There is absolutely no way it feels like a conventional motor coach steering system.  It feels far lighter, perhaps at first, too light. It does take time to get accustomed to driving with CD, but it’s a full control feeling, and as the name applies, it is Comfort Drive.

I had additional positive results using the CD equipped unit in varying weather and road surface conditions.  High winds, even gusty ones, required little or no steering wheel pressure as it automatically compensated to create a new wheel center.  Likewise, high sloped road crowns were corrected automatically centering the wheel and alleviating any driver input pressure.   An increase in safety margin in the case of a blowout is a feature that is not talked about, possibly due to liabilities involved of making such statements.  But, just think about it.  External forces of such things as road surface ridges do not cause any steering feedback pull.  A front tire blowout would have little affect on the steering wheel as the CD servo motor would deal with the majority of the steering pull involved.

After a number of trips, totaling several thousand miles, a great appreciation and respect grew for this unique feature.  So much so, that it was questionable that I would want anything less than CD on my next coach.  This feeling seems to be common among those that have this innovative steering aid.

The CD on Newmar’s 2009 coaches, are, and will come with an additional feature, an adjustment knob to vary the power sensitivity.  Personally I do not see the need for this add-on, however it may help some potential buyers overcome that “I need more road feedback” syndrome.  Hopefully, this is not used to partially defeat the benefits of this great automatic electronic steering aid product. 

Note: This article covers the basic operation and application of what we know as Comfort Drive, and is based on the opinion and product experience of the undersigned and that of other like owners.  Applications and results herein stated may vary do to many factors.  Those factors include, but are not limited to, coach weight and load, tire pressure, road surface profile, speed, curve radius if turning, etc. 

  

Keeping It Between The Lines         Lug_Nut              Peter Mercer

   

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Comments

15 Responses to “Comfort Drive, A Steering Innovation”

  1. Comfort Drive on April 20th, 2008 10:50 am

    [...] This post discusses a computer controlled steering system that actually improves handling on rough roads. The CD product is an electronic steering aid that is located between the steering wheel and the steering gear. It is not connected to, nor does it directly affect any portion of the hydraulic system. It is a software-driven computerized device that utilizes an electro servo motor to react to user steering input, steering gear feedback and self centering predictability. The steering input energy is substantially reduced requiring less force from the operator. The needed input force is slightly increased as the vehicle’s speed increases, but still remains lighter than normally experienced. More about this will follow a bit later. Steering wheel kick from the road is virtually eliminated for the user and is totally handled by the CD. Computing both the operator input and the steering gear feedback, the CD automatically predicts and corrects the steering center. Once this is accomplished the steering weight does not favor either direction regardless of road slope or wind forces. [...]

  2. gypsy John on April 20th, 2008 12:51 pm

    Sounds like with this CD product, we are just one step closer to that famous cartoon with the guy driving US Highway 50 across Nevada and puts his coach on Cruise Control and goes back and takes a nap.

    What will they think of next? Well lets see…they already have that laser that spots when you are to close to an object (front or sides) and will self correct. Now we have a gadget that will adjust your steering for you. YUP, I guess the time has come when we just put our 45 foot behemoths on Auto Pilot and let `er rip!!!

    Look MA…no hands & no brains!!! Thankfully the price of fuel (or where it is going) will keep most of these idiots off the road–eegads!

  3. Ray Palandri on May 10th, 2008 9:55 am

    I am very interested in this product for my rig. A 2007 Tiffin Phaeton 40 QDH. I have emailed TRW several times with no response. I realize that they have an exclusive arrangement with Spartan and Newmar until this summer, but I would have at least expected some kind of reply. I live in the Denver area and was interested in where I could obtain the product and how much it would cost. Do you have any suggestions???

    Thank you

  4. Lug_Nut on May 10th, 2008 10:30 am

    Ray, I don’t think that Comfort Drive is, or will be, available as an aftermarket product that can be added on. However, you never know. I think they will receive a substantially high request level for just that.

  5. Ray Palandri on May 10th, 2008 12:48 pm

    Lug_Nut,

    I’m sorry to hear that. It sounds like a great product and would be a welcome addition to my rig.

    Thanks for your quick response. Let me know if the situation ever changes.

    Thanks again,

    Ray

  6. Ray Palandri on May 10th, 2008 1:03 pm

    Lug_Nut,

    Are there any after market add-ons that will come close to the Comfort Drive in performance. (as you can see, I’m disappointed that CD won’t be available after market) Having just returned from a 500 mile and very windy day of driving, I would certainly welcome something that would aid in the constant job of correcting that one has to do when driving one of these big rigs.

    It’s the tension of having to constantly correct that really leaves me tired at the end of the day. I like driving and can, and have driven a car straight through for a 1,000 miles without being as tired as I have been in the motor home after only 300 or 400 miles.

    Thanks for your input,

    Ray

  7. Lug_Nut on May 10th, 2008 2:01 pm

    Ray, I’ve heard good reports on the Howard steering systems which are an after market add-on. Also, I wouldn’t give up yet as far as seeing if the ColumnDrive (TRW’s name for the Comfort Drive) is going to be offered as an aftermarket in the future.

  8. Ray Palandri on May 10th, 2008 2:28 pm

    Thanks Lug_Nut,

    I’ll try TRW again and look into the Howard Steering System also.

    Thanks,

    Ray

  9. Ray Palandri on May 12th, 2008 11:07 am

    Hey Lug_Nut,

    FYI. I just got off the phone with the local Camping World and they tell me that River City Products maker of the Howard Power Center Steering is out of business. I just now talked to a gentleman who is taking their calls and he confirms that the company is for sale and they are no longer, at this time, supplying systems. Bummer!

    I also finally did hear from TRW and they currently have no plans to offer it as an after market add on. He does say, however, that things could change and he woul let me know.

    In the meantime, what have you heard about the Safety Plus system?

    Ray

  10. Lug_Nut on May 13th, 2008 5:38 am

    I’m not fully familiar with the Safety Plus system. Perhaps you could post a request on rv.net for comments.

  11. John on May 27th, 2008 11:14 am

    I am in the process of researching my next motorhome and came across the “comfort drive” offered in Newmar coaches. Newmar mailed a DVD to me that goes into a very good overview of this latest creature comfort product. I can see the advantage of having this system on my next coach as a retired professional driver recalling the many corrective steering maneuvers I’ve had to use over the years. My arms and shoulders are not the muscle mass they used to be but I can live with that knowing that this steering assist system will make driving more of a pleasure.

    Lug_Nut,
    it is apparent how relaxed and effortless steering is in the photos you’ve included in this article. You appear to be very relaxed and are not white-knuckling the wheel with trucks on both sides. We know how turbulent the air can get in this situation. I will be test driving some coaches this summer and will make a point of driving a Newmar coach and experience first hand this innovative technology. It’s another step toward safer motor vehicles.

    Ray,
    If you’re interested in the DVD, I suggest getting in touch with Newmar and ask for their promotional Comfort Drive DVD.

  12. newmar motor homes on July 22nd, 2008 11:18 pm

    [...] steering systems and electronic steering aids, TRW. The name Comfort Drive is what it is termehttp://blog.rv.net/2008/04/20/comfort-drive-a-steering-innovation/Newmar RVs for sale motor homes, fifth wheels and toy haulers in Fort …Newmar RVs. Motorhomes, [...]

  13. Tom Lang on August 25th, 2008 8:12 pm

    I think the TruCenter steering stabilizer from Blue Ox offers many of the same benefits as Comfort Drive. Main difference is that it doesn’t reduce the steering effort and the self-centering is pushbutton controlled instead of automatic.

  14. Lug_Nut on August 26th, 2008 4:56 am

    Tom, I agree that they are similar, but both the automatic centering and the effortless handling add great value. The auto-centering, so it can be always employed and the power may be a great aid in the event of a blowout. Thanks for your input.

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