RX450h+ Fuel Economy
11-06-23, 08:21 AM
#1
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RX450h+ Fuel Economy
We've driven our 2024 RX450h+ 2,700 miles in the past 3 weeks, including a trip to the San Juan Islands of Washington from Fairfield, CA of 2,200 miles.
Raw gasoline fuel economy comes out to be 42.1 mpg over 2,500 miles, using miles divided by gallons of gas pumped. When I factor in the electricity, which comes out to be 159 kwh, which I estimate to be equivalent to about 10.6 gallons of gasoline, using 14.5 kwh per gallon, the "fuel economy" drops to 35.7 mpg. I use 14.5 kwh as I've seen that mentioned as the useable capacity of the battery and that corresponds fairly well to my calculations as well. The 37 miles of EV range that Lexus claims is close enough to the 35 miles combined that Lexus claims for gasoline HV mode fuel economy for me.
I have seen, based on the Total Average Fuel Economy indicator, as low as 28 mpg in the mountain passes at 60-70 mph,, and as high as 35 mpg with flat and level 55-60 mph speeds. I would occasionally reset the Total Average Fuel Economy by updating the trip history. In a pure HV mode from Redding CA to Fairfield CA, with mostly 70 mph on reasonably flat land, I saw 30.8 mph at 150 miles, increasing to 31.8 mpg with 16 miles of 55 mph speed for a total of 176 miles in that run. I don't have any examples of pure city driving in HV mode as I've been using EV mode in that situation. That's something I intend to do at some point though.
I did try the Charge Mode at one point on the freeway. It seemed to impact the fuel economy slightly, while extending the range 4 miles in 20 minutes, similar to a full-power L2 charger. I think the only time I'll use that feature is when I've accidently drained the battery completely and will not be able to charge it back up soon. At 70 mph, there is no noticeable difference from the engine noise and feel, but at low speeds, the engine is noticeable as it is revving higher instead of shutting down or idling. I imagine that fuel economy will be impacted more severely at lower speeds.
We did manage over 100 mpg in the first 400 miles of ownership, with mostly city driving and utilizing EV mode as much as possible. On our road trip, we were able to find free charging stations at most of the hotels we stayed at and I was able to top off the charge several times while eating or exploring towns. I ended up walking far more than I normally would, as I'd hook up to a charger and then set off on foot, where I'd normally just drive where I wanted to go, so that's another fuel savings as well as more exercise.
In pure EV mode, I've made two trips where I drained the battery from almost full. One was a mixture of city stop and go with rural highways and byways, never getting over 55, where I almost hit 50 miles at about 3.6 miles per kwh, and would of if I had completely filled the battery. For the other trip, it was a mixture of 55 mph steady speed on a freeway under construction and city driving. I made it 42 miles before draining the battery at about 3 miles per kwh. I don't have any examples of pure EV mode at speeds over 55, as I have proactively switched to HV mode above 55. I know from times when I've forgotten to switch for a while, that doing 70 in EV mode drains the battery pretty quickly. Forum member JSAM mentioned getting around 2.1 miles per kwh at 75-80 mph. I'll try different highway speeds in EV at some point.
I expect gasoline fuel economy to increase as the drivetrain breaks-in. Fuel economy also tends to improve as tires wear. We will be making another long road trip (about 3,000 miles) around Christmas, and I'll post the results of that.
All things considered, we are happy with the fuel economy and EV range. From an economic sense, EV mode will never pay for itself in our use case, but we enjoy the experience. From a purely economic sense, the RX350h would have made more sense, but we are getting practical real-world experience with EV life, without the range anxiety of a pure EV, and the poor EV charging infrastructure of anything non-Tesla. We do expect our next vehicle to be EV, and hopefully Lexus will have a more compelling EV offer at that time. It is looking like the infrastructure is on its way to improving.
Some frustrations are that there is no true total average fuel economy indicator like our 2013 RX350 had, or a mpg since last fill-up which the 2013 had as well. Also, while the miles per kwh indication is purely based on EV mode, the HV mpg indicator mixes EV miles in, so that you'll sometimes see over 99.9 mpg indicated. I wish there was more fuel economy related data available in the trip displays, and that it was broken down by EV and HV modes. Also, the trip summary only briefly appears after one shuts the car down, and if a door is opened, it only very briefly flashes. I'm unaware of how to retrieve the trip summary, or if that is even possible.
I also wish one could have the car default to HV mode, or a more intelligent Auto EV/HV mode that would switch to HV when at speeds over 55 mph or so. Several times, we've left it in EV mode when we wanted to be in HV mode, and used the charge on the freeway when we wanted to save it for city stop and go.
Another frustration is that HV range seems to have expected EV miles mixed in, as it starts out absurdly high with 577 miles when we purchased it, and even after 2,500 miles, it is still starting out at 470 miles, which would require 39 miles per gallon with a 2.5 gallon reserve, but when one runs it down to zero miles, it only takes about 10.5 gallons, indicating a closer to 4-gallon reserve. I'm still not sure it is completely filling up every time, as there seems to be a restriction when filling that causes the pump to stop early. I've put as much as 1.1 gallons in after the initial stop, but then overflowed with the pump handle set to the low-flow notch. Now I fill up at high speed, then wait a bit after it stops, then put in one more at about half-flow and leave it at that when it stops. That has put anywhere from another quart in, to half a gallon. It has yet to overflow again using that method. The 2013 was easier in this regard. Pump at high speed, and if you tried to add any more, it would only add a tenth or two, so I rarely bothered. The 2013 also never overflowed on the low flow setting.
Raw gasoline fuel economy comes out to be 42.1 mpg over 2,500 miles, using miles divided by gallons of gas pumped. When I factor in the electricity, which comes out to be 159 kwh, which I estimate to be equivalent to about 10.6 gallons of gasoline, using 14.5 kwh per gallon, the "fuel economy" drops to 35.7 mpg. I use 14.5 kwh as I've seen that mentioned as the useable capacity of the battery and that corresponds fairly well to my calculations as well. The 37 miles of EV range that Lexus claims is close enough to the 35 miles combined that Lexus claims for gasoline HV mode fuel economy for me.
I have seen, based on the Total Average Fuel Economy indicator, as low as 28 mpg in the mountain passes at 60-70 mph,, and as high as 35 mpg with flat and level 55-60 mph speeds. I would occasionally reset the Total Average Fuel Economy by updating the trip history. In a pure HV mode from Redding CA to Fairfield CA, with mostly 70 mph on reasonably flat land, I saw 30.8 mph at 150 miles, increasing to 31.8 mpg with 16 miles of 55 mph speed for a total of 176 miles in that run. I don't have any examples of pure city driving in HV mode as I've been using EV mode in that situation. That's something I intend to do at some point though.
I did try the Charge Mode at one point on the freeway. It seemed to impact the fuel economy slightly, while extending the range 4 miles in 20 minutes, similar to a full-power L2 charger. I think the only time I'll use that feature is when I've accidently drained the battery completely and will not be able to charge it back up soon. At 70 mph, there is no noticeable difference from the engine noise and feel, but at low speeds, the engine is noticeable as it is revving higher instead of shutting down or idling. I imagine that fuel economy will be impacted more severely at lower speeds.
We did manage over 100 mpg in the first 400 miles of ownership, with mostly city driving and utilizing EV mode as much as possible. On our road trip, we were able to find free charging stations at most of the hotels we stayed at and I was able to top off the charge several times while eating or exploring towns. I ended up walking far more than I normally would, as I'd hook up to a charger and then set off on foot, where I'd normally just drive where I wanted to go, so that's another fuel savings as well as more exercise.
In pure EV mode, I've made two trips where I drained the battery from almost full. One was a mixture of city stop and go with rural highways and byways, never getting over 55, where I almost hit 50 miles at about 3.6 miles per kwh, and would of if I had completely filled the battery. For the other trip, it was a mixture of 55 mph steady speed on a freeway under construction and city driving. I made it 42 miles before draining the battery at about 3 miles per kwh. I don't have any examples of pure EV mode at speeds over 55, as I have proactively switched to HV mode above 55. I know from times when I've forgotten to switch for a while, that doing 70 in EV mode drains the battery pretty quickly. Forum member JSAM mentioned getting around 2.1 miles per kwh at 75-80 mph. I'll try different highway speeds in EV at some point.
I expect gasoline fuel economy to increase as the drivetrain breaks-in. Fuel economy also tends to improve as tires wear. We will be making another long road trip (about 3,000 miles) around Christmas, and I'll post the results of that.
All things considered, we are happy with the fuel economy and EV range. From an economic sense, EV mode will never pay for itself in our use case, but we enjoy the experience. From a purely economic sense, the RX350h would have made more sense, but we are getting practical real-world experience with EV life, without the range anxiety of a pure EV, and the poor EV charging infrastructure of anything non-Tesla. We do expect our next vehicle to be EV, and hopefully Lexus will have a more compelling EV offer at that time. It is looking like the infrastructure is on its way to improving.
Some frustrations are that there is no true total average fuel economy indicator like our 2013 RX350 had, or a mpg since last fill-up which the 2013 had as well. Also, while the miles per kwh indication is purely based on EV mode, the HV mpg indicator mixes EV miles in, so that you'll sometimes see over 99.9 mpg indicated. I wish there was more fuel economy related data available in the trip displays, and that it was broken down by EV and HV modes. Also, the trip summary only briefly appears after one shuts the car down, and if a door is opened, it only very briefly flashes. I'm unaware of how to retrieve the trip summary, or if that is even possible.
I also wish one could have the car default to HV mode, or a more intelligent Auto EV/HV mode that would switch to HV when at speeds over 55 mph or so. Several times, we've left it in EV mode when we wanted to be in HV mode, and used the charge on the freeway when we wanted to save it for city stop and go.
Another frustration is that HV range seems to have expected EV miles mixed in, as it starts out absurdly high with 577 miles when we purchased it, and even after 2,500 miles, it is still starting out at 470 miles, which would require 39 miles per gallon with a 2.5 gallon reserve, but when one runs it down to zero miles, it only takes about 10.5 gallons, indicating a closer to 4-gallon reserve. I'm still not sure it is completely filling up every time, as there seems to be a restriction when filling that causes the pump to stop early. I've put as much as 1.1 gallons in after the initial stop, but then overflowed with the pump handle set to the low-flow notch. Now I fill up at high speed, then wait a bit after it stops, then put in one more at about half-flow and leave it at that when it stops. That has put anywhere from another quart in, to half a gallon. It has yet to overflow again using that method. The 2013 was easier in this regard. Pump at high speed, and if you tried to add any more, it would only add a tenth or two, so I rarely bothered. The 2013 also never overflowed on the low flow setting.
Last edited by WellsB; 11-07-23 at 09:20 AM.
11-07-23, 09:06 AM
#2
Very nice and lengthy analysis, WellsB. I concur with what you have determined and also agree with the many "head-scratchers" that Lexus/Toyota has implemented. There is definitely room for improvement. Nevertheless, I am enjoying my RX450h+ a lot and am looking forward to the new NX450h+ which we will hopefully be obtaining soon. My wife likes the RX but, likes the feel of the slightly smaller NX version. Since I do nearly all of my own maintenance on my vehicles, this should make things much more simple. Many thanks for your insight and input.
Last edited by StefanoS; 11-08-23 at 08:29 AM.
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WellsB (11-07-23)
11-10-23, 02:11 AM
#3
Pole Position
Glad others are mentioning the there is a restriction in the gas filling system. I have to pump at the slowest possible speed or the pump constantly kicks off. It doubles or triples the time required to fill my tank. Maybe an EV would not be this slow😡
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WellsB (11-10-23)
11-10-23, 07:09 AM
#4
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Yeah, it seems like it's been a long-running issue with RAV4/NX/RX, but Lexus/Toyota will only address it if it is an extreme case.
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StefanoS (11-11-23)
11-11-23, 07:00 AM
#5
I tank up at Costco and I agree that the shut off issue is a nuisance. I generally fill up at the high flow rate until it hits shut off. I then switch to a slower fill rate until I hit shut off again. Then, once more and I'm done. If you go overboard and try to squeeze too much in, you are faced with the possibility of flooding the charcoal canister which can be an expensive replacement. Having previously owned and operated a automobile parts business for 37 years, I have sold a lot of those canisters and I don't want to be on the buying end of one of them.
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lexusnyca (11-11-23)
11-11-23, 07:06 AM
#6
As an addendum to my post, I have noticed that I have seen a difference in the shut off sensitivity at different fuel pumps, especially at Costco. I know zero about gas station pumps but, I wonder if there is a pressure adjustment on the safety shut off mechanism. Periodically, I have noticed a pump or two that are especially sensitive and therefore, annoying and keep shutting off, regardless of where the nozzle is placed in the fuel tank neck. Some of them are clearly a PITA.
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WellsB (11-11-23)
11-11-23, 07:46 AM
#7
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I almost exclusively use Costco, but the first time I overflowed was at a Shell. The second time was a Costco. Both times on the low flow setting. The Costco pump was the one where I put over a gallon in on low flow, after tripping on high flow though. The Shell pump took hardly any before overflowing on low.
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11-11-23, 10:00 AM
#8
This kinda makes me believe that there must be a pressure sensitivity adjustment on these pumps, as your experience sounds as if it those pumps were under adjusted.
11-22-23, 07:47 AM
#9
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In the process of running our RX450h+ down to empty, to prove the 14.5-gallon capacity of the tank, I made some city drives, a freeway drive where I'd normally use EV, and a loop through a typical California traffic jam multiple times. I reset the trip data each time so I was able to get some more HV fuel economy examples in drives where I'd normally use EV mode.
The first was a 2-mile non-congested city street run to some public chargers with the engine starting from dead-cold. Ambient temperature was about 55 degF. This would be a worst-case scenario where one would normally use EV. Indicated fuel economy was 21.2 mpg. I was charging to establish an EV reserve of 75% SoC. I would not use any of this charge until the engine shut down due to fuel starvation.
I spent an hour at the public charger, then made a 3-mile city street run that brought the fuel economy up to 29.8 mpg. I continued driving on city streets, including some 45 and 55 mph thoroughfares that have traffic lights and some instances of moderate congestion. This brought the trip length to 17 miles, and fuel economy was 31.3 mpg. I then made a 14-mile drive at 55 mph back home on a freeway under construction, but with no congestion. Fuel economy climbed to 36.1 mpg by the time I got back home for a total trip length of 31 miles.
My next trip was on a 65-mph freeway with no real congestion. Trip length was 21 miles and fuel economy was 35.3 mpg.
I then drove back home, the same 21 miles and same freeway, but this time with charge mode on for the freeway portions. Fuel economy was 32.8 mpg. I picked up 3 miles of EV range in that time.
The vehicle sat for an hour, then I made a 66-mile run on a freeway under construction. The loop was 36 miles in length and featured a low-congestion 55 mph run in one direction, and heavy congestion stop-and-go traffic in the other, for approximately 2/3rds of the 18-mile run. Fuel economy for the first run, which was on the heavily congested section, was 42.3 mpg. Going the other direction on the uncongested portion, brought fuel economy up to 44.2 mpg. By the end of the second circuit of the entire loop or 66 miles total, 46.2 mpg was indicated. I left the cruise control engaged most of the time, and Traffic Jam Assist was activated multiple times.
As the tank ran dry, 138 miles after the Refuel indicator lit, the engine started running rough, but set no codes. It did that for a few minutes, then the following warning displays came up.
"System Malfunction / Visit your Dealer"
"Drive-Start Control Malfunction / Visit Your Dealer"
"Hybrid System Malfunction / Visit your Dealer"
There was another warning that I was unable to record, but it said Reduced Power Available, or something to that effect.
A P0087 "Fuel Rail / System Pressure Too Low" code was set.
The EV range indicator changed to a series of dashes.
After filling up, I reset the code and the warning displays went away. The engine started up and ran fine as I drove the 3 miles home.
I filled up at a Costco with the nozzle set to high flow. It tripped with 14.3 gallons pumped. I then hand-held the nozzle at mid-range flow, and the pump tripped at 14.526 gallons pumped. I didn't attempt to put any more in, as 14.5 gallons is the specified maximum fuel capacity. I estimate that the 138 miles after the Refuel indicator lit averaged about 39 mpg or about 3.5 gallons of reserve. Now that I know with certainty that the tank holds 14.5 gallons, I'll be able to firmly establish the reserve over time.
The first was a 2-mile non-congested city street run to some public chargers with the engine starting from dead-cold. Ambient temperature was about 55 degF. This would be a worst-case scenario where one would normally use EV. Indicated fuel economy was 21.2 mpg. I was charging to establish an EV reserve of 75% SoC. I would not use any of this charge until the engine shut down due to fuel starvation.
I spent an hour at the public charger, then made a 3-mile city street run that brought the fuel economy up to 29.8 mpg. I continued driving on city streets, including some 45 and 55 mph thoroughfares that have traffic lights and some instances of moderate congestion. This brought the trip length to 17 miles, and fuel economy was 31.3 mpg. I then made a 14-mile drive at 55 mph back home on a freeway under construction, but with no congestion. Fuel economy climbed to 36.1 mpg by the time I got back home for a total trip length of 31 miles.
My next trip was on a 65-mph freeway with no real congestion. Trip length was 21 miles and fuel economy was 35.3 mpg.
I then drove back home, the same 21 miles and same freeway, but this time with charge mode on for the freeway portions. Fuel economy was 32.8 mpg. I picked up 3 miles of EV range in that time.
The vehicle sat for an hour, then I made a 66-mile run on a freeway under construction. The loop was 36 miles in length and featured a low-congestion 55 mph run in one direction, and heavy congestion stop-and-go traffic in the other, for approximately 2/3rds of the 18-mile run. Fuel economy for the first run, which was on the heavily congested section, was 42.3 mpg. Going the other direction on the uncongested portion, brought fuel economy up to 44.2 mpg. By the end of the second circuit of the entire loop or 66 miles total, 46.2 mpg was indicated. I left the cruise control engaged most of the time, and Traffic Jam Assist was activated multiple times.
As the tank ran dry, 138 miles after the Refuel indicator lit, the engine started running rough, but set no codes. It did that for a few minutes, then the following warning displays came up.
"System Malfunction / Visit your Dealer"
"Drive-Start Control Malfunction / Visit Your Dealer"
"Hybrid System Malfunction / Visit your Dealer"
There was another warning that I was unable to record, but it said Reduced Power Available, or something to that effect.
A P0087 "Fuel Rail / System Pressure Too Low" code was set.
The EV range indicator changed to a series of dashes.
After filling up, I reset the code and the warning displays went away. The engine started up and ran fine as I drove the 3 miles home.
I filled up at a Costco with the nozzle set to high flow. It tripped with 14.3 gallons pumped. I then hand-held the nozzle at mid-range flow, and the pump tripped at 14.526 gallons pumped. I didn't attempt to put any more in, as 14.5 gallons is the specified maximum fuel capacity. I estimate that the 138 miles after the Refuel indicator lit averaged about 39 mpg or about 3.5 gallons of reserve. Now that I know with certainty that the tank holds 14.5 gallons, I'll be able to firmly establish the reserve over time.
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11-23-23, 06:01 PM
#11
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It really depends on the type of driving. Our overall HV average is around 35 mpg over 3,100 miles Our worst HV fuel economy that I've noted from the vehicle trip mpg has been 21 and the best has been 46. On a per tank basis, its been 28 - 40 mpg. The other RXs have a 17.8(non-hybrid) or 17.2 (hybrid) gallon tank. The 450h+ is 14.5 gallons
Last edited by WellsB; 11-23-23 at 06:26 PM.
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StefanoS (11-25-23)
01-02-24, 10:48 AM
#12
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We just returned from a 3,400 mile road trip from the San Francisco Bay Area to SE Arizona and back, where very little charging was available during the trip, roughly 6 kwh. This trip involved a lot of 70 and 75 mph interstate runs, rural highway, and slow driving through parks. We also went through multiple mountain passes and experienced cold weather, as low as 19 degF, though around 30-50 degF on average. We averaged 33 mpg on the trip. Fuel economy ranged from 29 to 36 mpg on a per tank basis. I run 91 octane E10 fuel and run in normal mode with normal climate control settings.
Lifetime fuel economy is 35 mpg over 7,100 miles with EV charging factored in, and 37.7 mpg without EV factored in.
Lifetime fuel economy is 35 mpg over 7,100 miles with EV charging factored in, and 37.7 mpg without EV factored in.
Last edited by WellsB; 01-21-24 at 06:59 AM. Reason: Math errors
01-02-24, 10:59 AM
#13
We just returned from a 3,400 mile road trip from the San Francisco Bay Area to SE Arizona and back, where very little charging was available during the trip, roughly 6 kwh. This trip involved a lot of 70 and 75 mph interstate runs, rural highway, and slow driving through parks. We also went through multiple mountain passes and experienced cold weather, as low as 19 degF, though around 30-50 degF on average. We averaged 33 mpg on the trip. Fuel economy ranged from 29 to 36 mpg on a per tank basis. I run 91 octane E10 fuel and run in normal mode with normal climate control settings.
Lifetime fuel economy is 34 mpg over 7,100 miles with EV charging factored in, and 38 mpg without EV factored in.
Lifetime fuel economy is 34 mpg over 7,100 miles with EV charging factored in, and 38 mpg without EV factored in.
Last edited by StefanoS; 01-02-24 at 11:15 AM.
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WellsB (01-02-24)
01-02-24, 11:36 AM
#14
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Yeah, it was colder than I prefer, but I'll take cold over hot, lol. I'm certainly spoiled by the bay area weather. Thankfully we experienced no snow this trip, though I was prepared. The RX450h+ is a superb road trip vehicle.
01-02-24, 11:45 AM
#15
It's a bit of a toss-up, one can easily get sick of both hot and cold weather and, rather quickly, too. As for being a great road trip vehicle, I concur. That is exactly why I zeroed in on this particular PHEV. So far, it has lived up to my expectations.