In your first post you referred to the Lexus RX200h. Correct me if I'm wrong, but at least in my market there is no 200h. There is a CT200H and an NX200t, but not an NX200H. The hybrid version of the NX200t is the NX300H. So, when I referred to the non-existent NX200h as being a small hatchback, it was because your mention of a NX200h threw me off. I agree that the NX300h, which you probably meant, is the same platform as the Rav4 Hybrid.

While trying to find proof that the Rav4 Hybrid has 3 electric motors, I came across an odd thing. Most car reviews about it state that it has two electric motors, one of which is in the rear axle. None of the reviews go into any detail or don't even mention the transmission used. They do consistently claim that the Rav4 Hybrid uses Toyota's Hybrid Synergy Drive (HSD). HSD is used across the range of Toyota hybrids, and one of the signature features is that the cvt contains two electric motors. If the Rav4 Hybrid uses HSD, then by definition it has a total of 3 electric motors. Automotive journalists are notorious for factual errors about hybrids, and also take shortcuts where they think their audience doesn't care. I've seen a review of the Escape Hybrid that claimed the awd version used a third electric motor to power the rear wheels, which certainly was not true.

I am not describing the Escape Hybrid's awd system as the multi-mode 4wd system. My guess is that multi-mode 4wd is a marketing term applied to the same system as the Escape Hybrid's, but with the addition of some software controls that either purport to match certain conditions, or actually fine tune the system for those conditions. The Escape's system, besides monitoring for wheelspin, also monitors speed, throttle position and steering wheel position, among other things. So, for instance, when you pull away from a stop, it automatically engages the back wheels - because wheelspin is likely when pulling away from a stop. In that sense it does magically control the rear wheel engagement for all conditions and without driver control. I know it works surprisingly well, and I have driven a variety of less and more capable vehicles in conditions that took them to their limits. Multi-mode 4wd, as I said, probably is based on the same setup, but may or may not make it work better.

Edit: I should add that the engagement of the rear wheels is variable, depending on the calculations of the computer that monitors the sensors. I've set up a gauge to watch the degree of engagement of the rear wheel electronic clutch, and when it is not zero, it is constantly changing.

Manufacturers don't necessarily disclose all the technology in their cars. For instance, the Escape of the vintage we're discussing had something called pull/drift technology. They have electric steering. In some circumstances, such as a constant side wind or a sharply crowned road, the steering wheel has to be constantly pushed to stay on track against the tendency to be pushed off the road. The electric steering senses this after a while, and adds that input by itself. This is supposed to relieve muscle strain on the driver. Ford never mentioned this feature.

Overspin. Just look it up if you don't think electric motors can be damaged by it. I'm not sure if the danger is overheating or physical damage. The early Prius had a problem that the traction control system used to protect an electric motor against overspin was so aggressive that they would pretty well refuse to move if they got any wheelspin. To cure that the control was backed off to allow some limited wheelspin.
Just do a search for "prius overspin".

I will grant you that the 0-60 times for the Toyotas is much better than the FEH. I do doubt many people buy these things for drag racing. And presumably if you use that capability much it will hurt the mileage.

 

The other day I was in a situation where I had to move out from a stop and turn sharply at the same time. (Getting out of a parallel parking spot.) The curbside rear tire was on bare pavement and the street side tire was on sand on the pavement. As I made the move, the street side tire spun part of a rotation on the gravel, stopped and spun a bit again. Which indicated power was being applied to the rear wheels, even though I was barely moving. And the front tires never spun.

A more basic slip&grip awd system would not have engaged the rear wheels unless the front wheels spun.

 

Hey Ray,

32MPG? Wow. My 2006 FEH ~ 30 until recentl, down to 28.5 now.
Any tips?

Fletch

 

Almost all AWD systems work this way, distributing and redistributing torque to those axles/wheels with traction through open differentials many times per second (only takes 16 milliseconds for Ford's to react). To generalize, some AWDs have a more even 50/50 front/rear distribution (Subaru, Audi quattro) , some more FWD biased (like the Ford Escape and other small SUVs), and still others are more RWD biased (Mercedes 4Matic, BMW XDrive, Infiniti, Lexus, etc.) You can see this in action with comparisons in numerous YouTube videos. There's actually many subtle differences in these AWD systems even within the same manufacturer and different models.

 

Drive gently, coast to traffic lights when practical, avoid warmups and extended idling, keep it maintained, watch tire pressure, use air conditioning and defroster only when needed and slow down. I'd guess that 90% of the miles on mine was commuting to work and home. I had a 24 mile ride each way that was almost ideal for the hybrid. I took full advantage of that.