When Will R1’s Get 4-Wheel Steering?

[Rivian_Hugh_III]

Four-wheel steering seems like a gimme for an electric vehicle with a motor on each wheel. I’m surprised Rivians weren’t designed with it from the start, especially considering how visionary they have been about so many aspects of the vehicle.

Do you think 4-wheel steering is coming any time soon? Is it a challenging engineering problem? How much might it add to the cost of the vehicle? Is it necessary or just a gimmick on a vehicle like the R1’s where turn radius seems already pretty good?

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[Sgt Beavis]

Let’s get Tank Turn first.

That said, 4WS will require a significant redesign of the suspension. It’s a nice to have but I don’t think it’s that big of a deal.

 

[electruck]

It's extra weight (which translates to reduced efficiency), cost, and complexity that I have no interest in. Tank turn is a novelty. I might play in a snow covered parking lot given the chance, but I have no practical use for that either.

 

[Ladiver]

I had 4 wheel steer on a previous truck. I would buy it again in a heartbeat. Improved handling and much tighter turn radious.

The only question I have now is about their "K-turn". I can see how slowing the inside rear helps, but your front tires only turn so far? There will be scrubbing on those front tires.

 

[zefram47]

Let’s get Tank Turn first.

That said, 4WS will require a significant redesign of the suspension. It’s a nice to have but I don’t think it’s that big of a deal.

4WS would be much more impactful in day to day with the truck and way more sympathetic to the mechanicals. Tank turn is a gimmick that hasn't been released because it's too hard on the drivetrain and is really limited in where it can be used safely. You're not using tank turn on the trail, where 4WS would reduce the turning radius quite a bit. As elsewhere, I'd rather see K-turn than tank turn.

 

[E.S.]

Do you think 4-wheel steering is coming any time soon? Is it a challenging engineering problem? How much might it add to the cost of the vehicle?

I doubt it. Already they've delayed Tank Turning due to the safety complications it has potentially presented. 4 Wheel Steering will add even more complications to the equations Rivian has to fine tune to get Tank Turning perfected. If they do implement 4 wheel steering, I fear it will be at the cost of giving up Tank Turn.

 

[sub]

I think that long term it is likely that all wheel steering will become an available option on most higher end vehicles.

As far as Rivian R1. It would probably require extensive modifications to the design. Unless adding this at some point was part of the original design, I would not expect to see it until a major refresh in 5-10 years from now.

 

[bd5400]

If it's relatively easy to implement (acknowledging that it would require design changes) then I don't see any harm in introducing it down the line as an option for those that want it. Perhaps in the future when manufacturing is improved and customers can more specifically configure vehicles it would be possible.

 

[moosetags]

GM offered "Quadrasteer" on 1/2 ton pick-ups and 3/4 ton Suburbans between 2001 and 2005. I owned and towed with two of these four wheel steering Suburbans. This system worked great for backing a large trailer. I had a Suburban with the turning radius of a Honda Civic. I was very sorry to see this option discontinued.

Brian

 

[electruck]

Both Silverado and Hummer EVs will have 4 wheel steering for those that feel it's a must have. The Rivian's torque vectoring should similarly be able to reduce the turning radius a bit but likely not to the extent that 10-15 degrees of physical steering angle might. But then again, Rivian hasn't shared what the R1T turning radius actually is but somehwere I got the impression that it drives smaller than its size, so I guess we'll see. s00n, right?

 

[kylealden]

All other things being equal, I'd love four wheel steering.

All other things are not equal; presumably it adds significant cost, weight, mechanical complexity, and other factors that come at the expense of durability, reliability, and manufacturing simplicity. Those tradeoffs can likely be brought into balance for some vehicles under some circumstances, but clearly Rivian didn't feel the tradeoffs were right.

I wouldn't be surprised if it's more popular at some point, but the fact that it's pretty scarce in comparable vehicles is revealing, and I expect Rivian to aim downmarket before adding more exotic design elements.

 

[sub]

All other things are not equal; presumably it adds significant cost, weight, mechanical complexity, and other factors that come at the expense of durability, reliability, and manufacturing simplicity.

Why do you presume those things?

I agree that it feels like combining drivetrain and steering on the same axle should be difficult, but the cheapest and most reliable cars all have power and steering on the same axle.

If steering the front wheels on a FWD vehicle does not create expense/durability/reliability issues, why do you assume that steering the rear wheels an AWD vehicle would be problematic?

 

[ads75]

People asking for new features requiring new engineering and design, and all I want is for Rivian to be able to build what they currently offer in substantial quantities.

 

[kylealden]

Why do you presume those things?

I agree that it feels like combining drivetrain and steering on the same axle should be difficult, but the cheapest and most reliable cars all have power and steering on the same axle.

If steering the front wheels on a FWD vehicle does not create expense/durability/reliability issues, why do you assume that steering the rear wheels an AWD vehicle would be problematic?

Not so much that it's problematic (in principle not more complicated than any steered axle), just intrinsically more complex. You're doubling the number of steered axles. You're adding linkages and axes of travel where previous there were none. More parts, more complexity, more cost. (And, since it likely would only be on some trim levels - more SKUs, more assembly line fragmentation, more scaling challenges.)

Not at all impossible, but the fact that the tradeoffs are at least debatable is self-evident from the fact that they chose not to do it. If it was easy and obvious, it would be in the R1T (and more vehicles generally).

 

[moosetags]

I had two Quadrasteer Suburbans. I loved the feature and was sorry to see it go away. The last year that it was offered was 2005. It was especially useful when backing a trailer. I watched the short driving video of the new Electric Silverado. The vehicle in the video has four-wheel steering.

Brian

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