I noticed that some days under identical driving conditions as far as weather temperature charge level, speed and traffic, EV mode will not engage.
Another thing that is not consistent, is that while cruising in the highway at 65 mph for 30 min or so, the charge level does not go up although the power distribution indicating says it is being charged.
Do any Hybrid driver’s experience the same?

 

couple of things to pay attention to and my observations.

1) the power distribution may (and does) show power going to the batteries, but at the same time, using the electric motors for driving, especially the rear wheel drive.
I've seen mine showing the batteries charging but the rear electric motors running. The next effect might be zero charge, especially once the batteries are about 1/2 charged. What I have experienced is that on the highway on pretty flat roads where you are at a constant speed battery capacity stays pretty constant. If you go down an incline or drop speed, then the batteries charge pretty quick.
2) I've found that after cold start how soon EV mode invokes is highly dependent on how quick the gas motor comes up to temp. Next even headwinds can change how EV mode invokes. And last it seems to be pretty sensitive to throttle position. I've found that I accelerate to cruising speed at a decent rate then let off the throttle. That seems to be the most consistent mode to get to EV mode. And best luck by just letting off the throttle to get to EV mode rather than keeping the foot on the gas, then light throttle.
3) I've found that if the battery is near zero charge, stopping at a light or slowing down will keep the engine running for a while to charge the battery.

I've decided that Acura has focused the hybrid on performance and being as non instrusive as possible, rather than focusing on getting the last drop of EV performance at the sacrifice of performance and seemless driving. I've felt that they could have made the transition from battery power to gas motor on acceleration occur at a higher acceleration rate than they do. But in the end, I like what they have done by focusing on performance and by the way better in town mileage.

It would have been nice to add another driving mode "Max EV mode" or something like that that you could choose while still having the "comfort, normal or sport" mode invoked.

We looked at some other hybrids, and decided they sacrificed performance to get the most out of the hybrid hype. Less overall horsepower, less performance. Not as good a driving experience.

 

Pretty much the same experiences with my MDX hybrid with 100% EV mode is dependent on multiple factors to engage consistently at city speeds. Little-to-no 100% EV mode is utilized if any of those factors you listed above are off by a tiny bit. I do think the EV+gas motors are engaged more often together reducing I.C.E. engine load. I usually range from 1/3-2/3 battery pack charge on hwy runs of 70-80 mph. Never ever seen the MDX battery pack at 100%; except, in Sport+ mode.

I'm really hoping on the next gen MDX hybrid Acura will provide:
- increase the battery pack size
- add an "ECO" or "MAX EV" mode
- add an EV plug for the battery pack to top off (maximize EV usage with city driving of under 20 miles/45 mph and take advantage of EV parking spots around town)

I've also noticed my 18 RLX hybrid engages 100% EV mode sooner and longer compared to my MDX. There are times when my EV battery pack is charged to 100% in the same driving situations as the MDX. The RLX comes in at 100lbs less than the MDX and the RLX comes with larger performance tires. I can see 2-3 higher combined mpgs in the RLX in the same driving conditions compared to the MDX. I don't think the improved aerodynamics of the RLX are that much of a factor in city driving. Maybe the 3.5L RLX engine doesn't have to work as hard to provides electric motor power and faster battery pack recharge compared to our 3.0L in the MDX hybrid for city driving?

 

mrgold35

I'd also love to see a "Max EV" use/mode as well. As long as they don't eliminate the "comfort, normal, sport and sport+ modes) Although even DW set the sport mode as the default.

I have seen my battery at 100% charge a few times. There is a steep downhill near our house we go down on occasion, around a 15% grade. starting at the top, as I go down it takes about 1/2 way down (maybe 1/2mile) to get the battery fully charged if it is around 25% at the top. after that the engine starts up and downshifts to hold the speed down. On the highway it does seem that the battery charging is minimal unless there are downhill stretches or enough slowdowns from traffic to let regen braking do some charging.

What I have found is that short around town trips on flat ground can be almost all EV. By short <3 miles. To the local grocery store, It is on gas most of the way to it to get the engine warm etc. and about 20mpg. On the way back of the 3 miles I've had times were EV was in the 2 mile +/- range and high 30mpg.

I'd go for a larger battery if it doesn't affect cargo space or spare tire space! A few of the hybrids we looked at with longer range the battery impacts cargo and/or spare tire space. Worst is the spare tire. Either run flats or a inflator but no space for a real spare, One had a donut spare, but the well was NOT large enough to hold a real tire. I guess the passenger would need to put the spare on their lap! We travel enough in places where even a run flat wouldn't work. It could be 200-300 miles to a town that might have a tire shop with a real tire and even run flats aren't meant to last that long when flat. Never mind the ride/cost/handling issues with run flats.

All that said, the MDX hybrid (and I suspect the RLX) are the most seemless and least intrusive hybrids of the ones we have driven. Some would drive me nuts on how they go between electric and gas. It may gain some efficiency, but not driving smoothness, or they give up performance for economy.

 

There is a 2+ mile steady uphill section of highway road not far from me that demonstrates how the MDX Sport Hybrid is completely different than the Volvo XC90T8 hybrid. At highway speeds when I start the uphill section of road with a nearly full battery charge, the MDX will consume the entire battery assist before I get to the top of the hill, then take quite a while to completely recharge back to the standard 1/2 charge status. In the Volvo it consumes about 8 of the available 21 miles of EV only range when in hybrid mode (combination of ICE and EV assist or can be 100% EV only driving), 10 miles while in power mode (ICE fully engaged with 100% EV supporting thrust all the time), and 15 miles in pure all EV mode (EV only thrust). When going back down that same hill, the MDX Sport Hybrid gets back to full available battery before I get to the bottom, and the Volvo recaptures about 70%. Now the battery systems are entirely different and the storage capacity is entirely different too so this may not be the best comparison, but it is interesting for discussion purposes. The MDX Sport Hybrid is 700 lbs lighter. However when the battery is completely spent, the vehicle seems more labored while the Volvo is largely unaffected. I think this is because the MDX has a less powerful ICE engine than the Volvo, but that is not countered by the weight differences. The one glaring difference between the two is the MDX Sport Hybrid is getting around 28-32 mpg and the Volvo XC90T8 hybrid is holding steady at 58-62 mpg in the same driving activities in our household. I have 501 miles on this tank of gas and have not yet passed the 1/2 fuel mark. Just some observations.

 

Thanks for the comparison, It's a Good summary comparison of two different types of hybrids, plug in vs. what I'd call a "mild" hybrid. the volvo being a plug in with deffinitely more range, I wouild expect that if you do short trips and keep it plugged in should give much much better in town mileage than the MDX. The definite advantage of a plug in battery with a 20 mile or so range vs. a mild hybrid like the MDX. The audi Q5 hybrid would likely give similar short trip mileage comparable to the volvo. The plug-ins advantage is fantastic short trip mileage. The mild hybrid like the MDX advantage is it gives short trip mileage comparable to highway mileage.