Why don't vehicles have electric water pumps and A/C units?

[CookingWithGas]

@joema

I think the Infiniti Q50 uses steer-by-wire, but still has some kind of fail-safe mechanical backup.

It is so, according to Wired:

Steering response is quicker and more precise than in a mechanical setup. Electronic control makes the car’s lane control system—which steps in when the driver drifts out of his lane on the highway—more effective. The system can adjust steering through electronic instead of mechanical inputs, which requires less work.

If Infiniti ever has the guts to go for the lobotomy and strip out the mechanical steering system (it left it in there as a backup)[…]

[jz78817]

@CookingWithGas

It is so, according to Wired:

that article is far too credulous, IMO. it sounds like they just re-printed what Nissan told them. 'cos there’s autonomous test vehicles running around out there today which seem to be able to steer just fine using the existing EPAS motor to steer. there’s hundreds of thousands of cars out on the road today with lane keeping assist and auto park which work just fine using the existing EPAS motor. Comparing it to “fly by wire” aircraft is a bit silly; fly by wire is useful on airplanes since the “steering wheel” (yoke/sidestick) is operating things which can be 200+ feet away. The steering wheel in a car is connected to the steering gear by a straight metal rod. Nissan/Infiniti (as well as a couple other Japanese manufacturers) seem to think the way to get people to buy their cars is to put as many weird, novel gizmos into them whether or not they provide any benefit. kind of like the variable compression ratio engine (also from Infiniti.) A significant increase in cost and complexity just to get it to make competitive power and fuel economy?

[pullin]

I’ve rummaged around the engine compartment of our 2013 Camry Hybrid, and I can’t see a belt anywhere. AFAIK everything is run electrically, or perhaps (in the case of the alternator) it’s geared somewhere and those are invisible from an overhead observer.

Feel free to correct me, I just can’t find any visible belts.

[jz78817]

You’re very likely correct. The Fusion hybrid/Energi has no accessory belt either.

[AskNott]

From what’s been said here so far, there’s a lot to be said for electric water pumps. In addition, there’s a hazard in having a failure-prone mechanical pump tied in with everything else on a serpentine belt.

[SamuelA]

Another huge advantage not mentioned : you can sense commanded and actual motor speeds for the water pump via the can bus. So when they don’t agree you can throw a DTC code and whoever repairs the vehicle will know right what the problem is. In principle this could be made so good, with self diagnosing subsystems, that robotic mechanics would be possible or DIY repairs would be easy.

[jz78817]

@AskNott

From what’s been said here so far, there’s a lot to be said for electric water pumps. In addition, there’s a hazard in having a failure-prone mechanical pump tied in with everything else on a serpentine belt.

serpentine belts with automatic tensioners have reduced water pump wear-out considerably compared to the side loading of old V-belt systems. especially ones over-tensioned.