I know I need to update my sig. Even though you folks can't see it, we have a 2016 RX 450H in Eminent White Pearl, purchased in March with 62,000 miles. I departed my normal practice of having an indie shop conduct a pre-purchase inspection because: extensive service records reveal a history of open-checkbook attention at Lexus dealers, 60,000 mile service accomplished in the week prior, and a high net worth owner who babied it, kept it 100% garaged and it presented like-new, right down to zero body flaws (not a single scratch or ding) and a blemish-free interior. I know my conclusion was an extrapolation based on observations, but I believed the care and attention to detail exhibited by the seller placed odds of a hidden mechanical discrepancy at < one percent or so. The car was simply too spectacular to have a problem That view has not changed, but I do have questions about the EV function. During the five months/6,000 miles we've driven her, the car has never been in a shop except for emissions testing.

Having never owned or driven any sort of hybrid previously, I had certain expectations that may or may not be grounded in reality. I've been accused by some of being too "verbose," in some of my posts, I'll try to keep it simple, with bullet points and this summary statement: I'd like the EV mode to engage and endure for longer periods of time than it does and I expected to see a greater spread between city mpg and highway mpg (city better by at least two mpg). Here's some points to consider -

* I'm in Southern Nevada and recognize that 60% of our ownership period has been with daily high temps >100 and that battery performance will be impacted.

*Sitting idle, usually with AC operating, EV mode remains on for inconsistent periods ... sometimes close to five minutes, others less than one minute.

* Beginning a gentle roll on level ground, EV mode seems very short-lived; any more than 5 mph, and the engine fires, even with the gentlest gas pedal input.

*I might have seen all bars filled on the Energy Monitor battery icon once, but the best normal observation is six maximum, but four typical (are there eight bars total?).

*MPG since reset is 26.3, best tank MPG observed 27.5 on a 100% freeway road trip with included some mountains, but mostly flat near sea level driving at 70 mph.

*Energy bar graph approx. 26 MPG for most of its life, with about a 1 mpg decline in 2023. One bar in 2018 shows nearly 40 (obviously an anomaly).

Guess I expected more from the EV mode; tell me I'm deranged, if that's the case! But I thought that in serious stop and go driving, the EV mode would really shine. Sadly, my daughter's 2009 RAV 3.5 V6 equals the fuel economy of the 450H. I know there's a weight difference. But still, I'm disappointed.

To get a good test on Hybrid battery health, must I go to the dealer? Or a good indie shop? What about DIY through the OBD2 with something like Hybrid Assistant?

I'd appreciate any insights regarding what I should realistically achieve with EV mode and whether or not I may have a sickening hybrid battery. Thanks!

 

Bump - 74 views and no opinions?

 

Most people have a misunderstanding of how a Toyota hybrid works. The Atkinson cycle increases thermal efficiency but in doing so sacrifices low end torque the hybrid components are there to fill in the gaps. There are other benefits like instant torque off the line, reduced complexity like no alternator, and overall better gas mileage. What HSD does not do is give you any usable EV only range the hybrid battery is simply too small. Why Toyota never increased the hybrid battery size to say 10 kWh (instead of under 2) is beyond me.

tl;dr: your car is working exactly as intended. In my experience HSD increases fuel economy by about 20%.

 

I'm a bit confused by what you're saying, as I understand that Atkinson engines are more thermally efficient, and sacrifice some low-end grunt; but I cannot complain at the liveliness of this V-6 when it seems to be th sole motivator of the vehicle. Conversely, electric motors have insane, instant torque. I would have thought the electric drive in the 450h could consistently provide the initial motivation to a somewhat higher speed, and perhaps sustain something like a school zone cruise with no supplement from its gas colleague (even with a tiny battery - which will get charged soon). In my mind, I thought that in a brutal stop and go circumstance, like the PCH from Malibu to Santa Monica at 4 p.m., electric would rule from initial green to something like 10-15 mph, then V-6 comes online (in a very low load circumstance, given established inertia) until you lift foot to coast to the next stop ... something like 1/3 electric and 2/3 regen opportunity over a few hundred yards. My gut feeling is the motor/engine power exists to do this, and maybe the battery could support it, but hybrid logic does not seem to make that happen. On a similar note, our GX 470 has gobs of low-end torque, but it downshifts way sooner than necessary as a mild hill is encountered. Seems to be programmed to accommodate a four banger, not a gutsy V8. Again, I question the system logic.

Like I said before, perhaps I'm just a dreamer. But it's good to hear that our RX is probably performing within the realm of reasonableness. Thanks.

 

Hybrid battery simply lacks the storage capacity to do what you want. What you should be looking into is a plug-in hybrid, or go pure EV.

There are a bunch of vids explaining how HSD works, it is an ingenious system but don't mistake it for anything but gas engine propulsion. Without the gas engine at best you can drive 1 mile at very low speed, in my Highlander best I've done is about 0.6 miles without the gas engine running. All the energy comes from the gas engine (and a small amount from regen braking), the battery is a small buffer that improves the power and torque curve of the engine.

 

Understood, but I cannot roll more than five or six car lengths on EV even with the gentlest of pedal touch. But good to know I'm probably within the bounds of normal expectations.

 

Disagree with this observation. I owned a 2016 Rav 4 2.5L 4 cyl.and averaged 25 mpg combination driving. My 2017 RX450H I average 30.9 total. Getting just under 32 city and around 30 hiway and most of my driving is city and rural.Add to the fact the RX is way heavier, twice as quiet and comfortable, and a LOT more power, I think think this is excellent. Plus the fact you can tow 5,000 vs 3500 it's a no brainer. I'm in the PNW where summer temps are generally upper 70's to low 90's and winter average around 45.
On the over 25 mph EV use, you are dealing with smaller battery size in a hybrid vs EV and some compromise was made to keep the total cost competitive with ICE model IMO. BTW, I can travel about 2 miles in EV mode on flat with steady pedal at 25 mph or so with full battery.

2009 Rav 4 V6 is rated at 19 city 26 hiway.
https://www.edmunds.com/toyota/rav4/2009/mpg/

 

Are you driving using ECO mode? If not that is the first thing to try. It will be more difficult to drive with ECO/hypermiling tactics if you are using normal or sport.

It is difficult to try to get the vehicle moving completely by battery, and maybe unsafe if you are in traffic. You may want to switch tactics of using the EV just to maximize glide instead of trying to get pulse and acceleration out of it. Assuming everything is warmed up, charged, and ready, once you get the vehicle up to say 30mph, if you lift off the throttle, it should still drop into ev mode, then you can feather the throttle to maintain the speed via the battery.

If you are in +100F, possibly a lot of your poor mileage is due to AC. Especially your comments that the ICE cycles on when stopped.

Your comments that battery meter only cycles between 4-6 is not common. For me it easily goes to full, even a couple hundred feet hill descent it will fully regen and start engine braking. On a flat highway drive it drifts just with top 2 bars. There could also be something mechanically wrong like a stuck brake causing your car to drag and not regening well (as well as your tires if they are not LRR and "only" inflated to recommended).

Finally, fuel may be an issue, since we're going to winter fuel this should get better, but this may only be slight factor.

 

I live in the Colorado mountains and get 30-32 MPG in the summer. In the winter it drops down to the high 20’s. The gauge may show all the bars as full, but not too often. Likewise, it never shows lower than 2 bars. I am not sure if the gauge is just showing 20-80% or if it is showing 100%, because the algorithms Toyota uses keeps the battery between 20-80%, which is the best range for a battery to operate.
My RX goes to ICE and ECO all the time at low speed in heavy traffic, and the nice thing about the hybrid is that when in heavy traffic the A/C can be on with no degradation in power, because it the compressor is powered by a small electric motor