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Four-wheel steering can be Tesla's next innovation

Four-wheel steering can be Tesla's next innovation

I believe Tesla cars are better suited for four-wheel steering than any other ICE car in history that has attempted four-wheel steering. With Tesla cars, engineers have greater freedom on how to design the actuators and the software to enable the rear wheels to have a digitally-controlled adjustable steering radius. Imagine the possibilities of four-wheel steering with Autopilot. Self-parking algorithms can be improved with an additional variable of a rear steering angle complementing the front steering angle. High-speed maneuvers and low-speed maneuvers can be completely changed. Look at this video of the A* search algorithm that is based on a fixed straight-angle for the rear wheels - http://blog.habrador.com/2015/11/explaining-hybrid-star-pathfinding.html - and imagine how the maneuvers can improve with an adjustable rear radius. Translational movement in addition to tighter rotational movement can be made possible.

Roamer@AZ USA | December 16, 2015

I still own a 2003 GMC Denali pickup truck with Quadra Steer. I would have replaced it years ago if they still made the four wheel steering option. It is a wonderful truck to drive. I will never replace it unless I can buy another four wheel steer truck.

The truck parks and turns like a Honda Civic.

I think GM stopped making it because customers could not wrap their brain around controlling a vehicle that moved at the back and the front. With side sensors the problem of driving the back of the vehicle into the fast food drive up window could be solved.

sp_tesla | December 16, 2015

Great idea.
Hey, Yoyo the designer robot, might as well add a very luxury feeling of walking toward a rising driver Falcon Wing doors & welcome you to occupy next generation seats, priceless!
Take the opportunity to better the turning radius of X at 35.4"

Rocky_H | December 16, 2015

@Roamer, Yeah, I remembered seeing that there have been a few vehicles with 4 wheel steering. That seems incredibly useful in big trucks. I wondered why they did not become more popular.

Eletrek | December 16, 2015

IMHO it is useful in a large truck totally unnecessary on a Model S. With its 17" high center of gravity and terrific handling, 4 wheel steering would only add unnecessary complications both mechanically and in the software.

inconel | December 16, 2015

Do we have it in some Acura with "Super" handling and in the 911 Turbo/GT3?

jordanrichard | December 16, 2015

No 911 has 4 wheel steering.

Honda once had it on their Prelude, but it was really expensive as an option.

I see it as unnecessary complexity for an added limited benefit. Meaning, the rear steering feature cuts out at higher speeds, IIRC.

Haggy | December 16, 2015

I've had it on several cars, and it actually cuts out at lower speeds. If you watch cars go around curves and look at the front wheels, you will see that the amount of turn is relatively subtle. Rear steering need not be to the extremes needed for parking, but can be used for affecting the handling characteristics.

Four wheel steering makes curves and lane changes feel much smoother. If you are used to a vehicle with it, then driving an otherwise identical vehicle without it lets you realize what you are missing, but in the other direction I've had people tell me that they didn't feel the improvement. I guess it takes getting used to, or comes down to knowing when it's effective and how it fits in with driving style.

On some cars, it's done better than others, and although I like it, the lack of it wasn't going to make me not want to get a Tesla. I can think of many things higher on my list, and Tesla does plenty of other things for performance and handling.

I'd put it higher on my list than being able to name my car or having a self closing charging flap, but I'd put it much lower on my list than having my fob tied to my profile. I can think of many things that would be far easier for Tesla to do that would cost a lot less and give more value to drivers.

damonmath | December 16, 2015

Didn't the Stealth have all wheel steering? Or was it just AWD?

Bruce Williams | December 16, 2015

I have a tractor with four wheel steering. Drifts like crazy.

inconel | December 16, 2015

@jordanrichard
Are you sure? The 991 Turbo/GT3 have 4 wheel steering and it is coming down as an option in the 991.2 Carrera S as well now.

JackClark | December 16, 2015

The BMW 7 & 8 series have each seen models with 4-wheel steering. I have no doubt that the cost outweighed the gain; especially from BMW.

Red Sage ca us | December 16, 2015

I believe the Dodge Stealth SRT Turbo may not have had the four-wheel-steer option. I think that ability was reserved for the Mitsubishi version, the 3000 GTVR4. I think some Acura models had four-wheel-steer, but only for a short period of time. I think they just do a form of torque vectoring on their all wheel drive cars now, instead.

damonmath | December 17, 2015

@Red - You are correct about the 3000 GT, although the Stealth is listed in this article. Not sure if it was the SRT Turbo though:

10 Coolest Four Wheel Steering Cars

NameBrand | December 18, 2015

@Roamer I was just going to cite the early 2000s Denali and Suburban had Quadra Steer. I'm not sure if the new ones have it also.