OK, time for my 25 year old RX300 to go on to the next owner. I'm trying to decide between a 2025 RX350h and a 2025 RX450h+. My main concern about the 450 is, will using it in electric only (EV) mode shorten the life of the battery? Deep discharge (30 mile range) usually shortens batter life. Will it be worse on the 450 than a 350 in electric supplemental (hybrid) mode?

 

Do you plan on keep the new RX 25 years also? If that were my time horizon, I would only get gas only. On any electric, an ownership period that long is almost certainly going to involve some major repair regarding something in the hybrid-drive and battery.

 

EV batteries are going to be just fine for 10-20 years. If you still have the car and need a new battery pack, it will cost a fraction of what it does for full EV's. Maybe a few thousand.

I would only get the 450H+ if you plan on using the gas engine 80% of the time. If you are just driving around town mostly in EV mode, I would get the 350H or some other pure EV vehicle. The battery longevity aside, the gas engine in the 450H+ that you paid for is going to go to waste. Double edge sword.

Toyota and Lexus have been doing hybrids for years with cars going 150-200k miles without major battery/hybrid issues. The non-hybrid is turbo-charged which could be problematic down the road as it is a fairly new design.

The reason I went for the hybrid, is it is about same cost as a comparably equipment gas only model and I do use it for long road trips negating the EV aspects. However, the 450H+ is approximately. $14k more. That is a lot to recoup in gas savings. Even if you got free electricity from work, you would have to drive nearly 100k miles to recoup and that assumes $5/gallon of gas. The EV mode of the 450H+ has more HP and torque but so does a $40k Tesla model Y. You need to decide what is important to you. If you are willing to shell out nearly $80k for an RX, I personally would be looking at the Rivian R1S and go all the way EV.

$57,665 RX350 AWD Premium +

$58,215 RX350H AWD premium +

$72,610 RX450H+ AWD

 

I got the 450H+ primarily because I use EV-only mode 80+ % of the time. There is no concern with the traction battery life - it has been proven in the Rav4 Prime since 2021, before being put into the NX450H+ and then RX450H+.

There is a lot of misinformation about battery life online/forum/thread by people who do not understand new (or even old) technologies. The Rav4 Prime, NX450H+ and RX450H+ traction batteries are never deep discharged - the minimum charge level of the traction battery allowed is 30 % and the maximum is 90 % - Lexus does this to keep it in the mid-range to add significant margin to the traction battery longevity. In fact, the PHEV is just an extension of the hybrid design, providing additional traction battery capacity to do pure EV mode. If you doubt the PHEV battery longevity, you are automatically also doubting also the Hybrid traction battery's life - without realizing what you don't understand fundamentally.

Usually people go for the hybrid simply because it costs less. I couldn't possibly have gotten the 350H because I can't accept the low HP/Torque rating (and I also charge mostly for free).

 

Actually, my only reason for considering the 450h is the possibility that the Middle East will go to hell in a handbasket and we'll have long lines at the gas stations (or no gas) like we did in the early and late 1970s. I think the likelihood of that is small, so it's really like buying insurance - you probably won't need it but we buy it anyway to deal with worst case scenario.

Beginning to look like a 350h is the car for me. Trouble is, it's hard to find one that isn't padded to the eyeballs with extras that jack up the price to almost 450 levels!

 

According to the Dr Prius app, the traction battery will discharge as deeply as 10%, then it will be charged back up and held around 13% in HV mode. The 90% figure is correct. 10% in Dr Prius is shown as 30% in the Lexus app, while 90% in Dr Prius is shown as 100% in the Lexus app.

The system will also discharge the traction battery to 80% in Dr Prius when HV mode is used with a fully charged battery.

We bought the RX450h+ as a step towards EV. We do all our local driving in EV mode and almost all our road-trips in HV mode. We were pleasantly surprised to find it the equal of the RX500h in handling and performance.

 

Does the Dr. Prius app have full compatibility with the NX/RX traction batteries ? In that, the %-tages indicated by it can actually be trusted as authentic and applicable for the 18 KWh battery in the 450H+ ?

I don't think so. Here's the math and specs that contradicts the App.

We know that the 450H+ have 18 KWh traction batteries, per Lexus and reviewers etc - its a published spec of the traction battery. When the traction battery is discharged for 0 miles of EV range - and then we use an external charger (such as Chargepoint or home charger), the actual energy transferred, per the chargers are about 14 KWh. That shows that the total discharge capacity of the traction battery pure EV mode is 14/18 = 77 %. If you consider the inefficiencies involved in energy transfer at the charger - that chalks up to 30-35 % capacity left in the traction battery - when all of the EV-mode-available charge is used up.

 

I usually see a bit over 15 kwh when I charge from completely discharged.

 

I definitely don't, ever. The highest I have ever seen for my car is 14.1 KWh - both across Chargepoint and my home charger.

The mapping translation error from % charge in an app to actual battery % SoC is prevalent in the 12 V battery as well - where people assume that their Aliexpress Voltage Meter accurately reflects the the actual SoC of the Lexus 12 V battery, freak out over incorrect translation (as the App has an internal % SoC to Voltage Mapping table that doesn't match the Lexus 12 V battery designed for low voltages). Only 1 person in the NX forum seems to understand the underlying translation is wrong.

In any case, I only trust the empirical number of 14 KWh and 18 KWh and don't believe the Dr. Prius number.

And none of that matters, because the OP will not buy the 450H+ since the risk of running out of gas in the middle-east is accurately low

 

I'm using a Kill A Watt P3.