Noting some observations I had from my experience with an ~1500 mile road-trip to Death Valley National Park in the US, just at my 1 year ownership of the RX450H+.

• Absolutely couldn't/wouldn't have done the trip with any EV. Even in California that probably has the most robust charging infrastructure - availability of chargers in working order is a tall order to plan for. Especially since the working state of any charger is not necessarily guaranteed. Even gas stations are hundreds of miles apart, but their availability is deterministic.
• Within the remote park, very few working chargers exist at the resorts/hotels - and if you are lucky to have all chargers working, you'll have to compete with other EV owners for availability.
• My RX450H+ was flawlessly reliable, the primary reason I bought a Lexus/Toyota. I was relieved to have the ES1200 and did not carry any jump starter with me. I did not have to use it, and that's the point of the redundant system design it enables.
• I really pushed the hybrid/gas engine hard during the uphills, where it grunted hard - something unusual for it, as in regular life, I can hardly ever hear it. The car had 3 adults, and few suitcases, lots of water and food and such - so a heavy load. This is also unusual for my car, as I use the RX450H+ at least 80 % of the miles in EV mode around town and very rarely need to use the hybrid/gas engine.
• Tested the regenerative energy conversion strongly during downhills - and went from 18 miles of EV range to 41 miles of EV range during the trip - by strategically switching to EV-only mode during downhills. I felt the regenerative charging of the traction battery is stronger/better when forced into EV mode - but I don't have a hard way to prove so. However, it would appear that such strategic use of the 14/18 KWh traction battery would give the PHEV higher efficiency relative to a Hybrid, just because there is a larger traction capacity to recharge. So if someone has a commute with strong downhill/uphill components (?)
• Absolutely missed having a spare tire. This was a cost-saving and weight-saving (business) decision by Lexus to remove the spare wheel. I found myself avoiding some dirt-roads (not off-roads) to visit the vantage points. I will have to figure out getting a modern-spare or similar solution - as many failure modes of the tires cannot be fixed with fix-a-flat, so having a spare tire is non-negotiable in my view. Aside from the 12 V battery subsystem deficiency, which I've managed to resolve for myself, I now need to figure out to resolve this spare-tire deficiency.
• The seats were outstanding in their comfort.
• The comfort and sophistication of ADAS was close to perfection in my view. It doesn't promise or claim "full self-driving" nonsense - and keeps both the driver and the roads safer, by appropriate driver monitoring, aside from the road monitoring/control.

 

Totally agree that EV charging can be a challenge.

I frequently see people waiting for quite awhile for an available charger that isn’t broken in San Diego.

When I go on a road trip I would not want plan my trip based on charging station locations. Life is too short.

With my hybrid, it takes me 18 hours to drive from San Diego to Denver with stops for gas and food. My friend drove the same trip in a Tesla and it took him 36 hours. Part of the issue is the cold weather drops range considerably. The other issue is malfunctioning chargers. In theory it should have only taken 22-28 hours.

 

In case anyone has measured/verified this, I had a question about the gas-mileage measurement of the RX450H+.

As we know, both the App and the car UI itself are absolutely worthless for measuring the current experienced hybrid-gas mileage of the RX450H+. The only way to truly measure is to count the miles traveled vs. gas filled in the tank - all manually. I did not do this on my trip, as it can be a chore.

However, the car must be keeping an internal estimate of the gas mileage - as it uses that to project the gas/hybrid-only range for the PHEV. I am wondering if that is actually accurate - even if indirect ?

After the entire road-trip, during which I almost exclusively used the HV mode (never plugged in), I filled the tank with 4.05 gallons of gas - and the range went from 18 hybrid-only miles to 189 hybrid-only miles - that projection of range uses the car's internal mpg of hybrid-only mode to show the miles projection. So given this projection, the car's internal hybrid-only mpg equates to (189-18)/4.05 = 42.2 mpg.

Since the above includes the assumption that the car's internal mpg tracking is accurate - has anyone actually verified if that car's internal tracking is accurate or inaccurate, by actually counting miles vs. gas filled ?

 

This problem does not get enough attention. If you’re planning a trip depending on chargers being at certain locations, you may want to plan an alternate charging stop for this reason. Also, you may want to plan for a stop where there are several charge stations. One charging station out of eight being out of service is no big deal, but one out of one, IS! Of course, with a plug-in hybrid, this is not an issue.

 

My wife and I just completed a 1.5 week trip to the FL Keys and tallied up 1,964 miles driving. I agree with all your points @wrinkle , the RX450H+ is a great highway tool. I charged up twice during the trip, one at a parking garage, the 2nd at a hotel. I wanted to try out the on the road charge process, not really from any hard need.
Anyway, on the topic of tracking miles driven and fuel used, we have been logging this info from the day we picked it up. Of course there are numerous at home charging cycles peppered all throughout this data. And fuel bought at different weeks and different states. Maybe one of you number crunchers can use it, I’ve pasted it below.
Let me know if there’s some tidbit you might want, maybe I’ll have it, maybe not. Cheers.

$34.82 11.61 G 6284 mi 4/19/25 at Exxon

$30.00 10.35 G 5819 mi 4/16/25 at Wilm NC Exxon

$33.60 11.59 G 5413 mi 4/15/25 at SC Exxon

$16.00 5.52 G 5003 mi 4/12/25 top up at Key Largo Exxon heading N

$33.00 11.19 G 4684 mi 4/7/25 top up at Key Largo Exxon heading S

$20.00 6.76 G 4289 mi 4/5/25 top up at Kent Island Exxon

$40.09 12.53 G 3850 mi 3/29/25 fill up @ Royal Farms

$34.20 12.35 G 2989 mi 3/15/25 fill up @ Sam’s Club

$35.65 12.92 G 2221 mi 3/1/25 fill up @ Exxon Selbyville DE

$37.00 12.07 G 1243 mi 2/7/25 fill up @ local Exxon

$43.00 13.1 G 521 mi 1/25/25 fill up @ Royal Farms

$0.00 0 gal. 12 mi 1/16/25 tank full at dealer pickup.

 

We spent some time in Death Valley last year with the RX450h+. Going up one of those steep grades was the only time I've had the ICE kick in while in EV mode. EV simply didn't have the power to maintain speed in that section.

I have a calculation in my fuel spreadsheet to look at miles of range added per gallon and it is fairly linear except when only adding a few gallons when near full, where the miles added were less than when adding over half a tank.

The miles added per gallon are almost always in excess of the manually calculated value. Sometimes they are within 1 mpg, more commonly 2-3 mpg, but sometimes as far off as 10mpg, though that's usually during a high-speed run where the fuel economy drops well under average.

 

So I've been deliberately waiting in the car after I do any pure-HV (non-EV) trips, to read out the pure-HV mileage that shows on the dash about a minute after you turn off the car.

I have now seen mpgs ranging from 32 mpg to 36 mpg in those readouts, with numbers in between. I wonder if those are truly reflective of the mpgs per trip, given that data is not possible to extract other than manually during gas fills.

 

Amazing mileage if I understand the information you provided. (average of 52.5)

 

We've averaged 40.9 mpg over 25k miles. If I try to compensate for EV usage, it drops to 34.9. We're very happy with the fuel economy, compared to our previous 2013 RX350 AWD which averaged around 22.

 

@RBDan , thanks for that number crunching.
The top 7 lines (1/16 to 4/5) included frequent EV only travel and frequent charging at home so I can see why they have high numbers.
The dates after that were mostly highway travel with occasional in town driving. I do need to correct my statement above of charging up twice, later I remembered there was a 3rd charge at another hotel during our trip. This (3x) is way less charging than the 1/16 to 4/5 period. So I think the 4/15 to 4/19 figures are more representative of the ICE efficiency, which is similar to what @WellsB reports. The 4/12 line has that 3rd charge in it so the bumps up the figure.
That 52.5 average, I guess one could call that a MPGe value for my use case ?
Thanks again.

 

You're welcome @Janky59 my pleasure. Great mileage, can't wait to get mine in late May or early June.

I have never read a really good explanation of what MPGe means? Anyone?....

 

I would only trust the manual method of counting miles vs. gallons filled for hybrid-mode efficiency (which WellsB tabulates but I don't)

In my view, the EV usage should really be tabulated separately with miles/KWh to be meaningful - as the mpge fudges the two in a rather contorted manner.

In my case, I'm getting 2.9 miles/kWh so long as my tire pressure is 40 psi non-cold and California winter. The last time I filled couple gallons gas, the car projected miles increase on the dash that implies 45 mpg. Even if that is optimisitic by 4-5 mpg, 40-41 mpg for such a large car is excellent.

 

I consider MPGe to be off by at least 50%, and only useful for comparing EVs to each other. Miles per KWH is much more useful and allows one to easily estimate the actual cost for the electricity. We usually see around 3 miles per kwh, but we generally only use EV mode below 55mph and for urban driving, where EV is at its most efficient. I keep the tires at 33 PSI cold.

 

I do go up to 65 mph during my commute for for stretches, just to keep up with easing traffic, but don't for any stretch beyond few miles/minutes.

One thing I have noticed is that when charged fully, the car shows 45 miles of EV range. On the other hand, the dash also shows 2.9 miles/Kwh, which equates to 2.9*14 kwh EV-mode-battery capacity = 40.6 miles.

It seems to me that the car indeed has about 45 miles of EV range - when measuring actual distance traveled in pure EV mode - which would mean that the 45 miles range is the figure more trustworthy - and therefore the miles/KwH more trustworthy is 45/14 = 3.2 miles/KwH.