RX450H+ EV range and ICE consumption

[Ken R]

Anybody willing to share what they are achieving in m/KwH and fuel consumption when using the ICE on their RX450h+ to see how it compares with the equivalent NX?

[Xez]

Hi Ken,

According to the in car system I’m getting 2.6 m/kWh and a combined mpg of approximately 68. I’ve tried to strip out the EV equivalent miles and calculate a pure ICE mpg that came to approximately 38. This is averaged over 4300 miles starting last July.

I’ll be interested to hear from others of their experience.

[AWC]

Currently the central display reports between 2.1 m/kWh and 2.2 m/kWh but when I first got the car it was reporting 2.5 m/kWh. Total average combined milage is 48 mpg over the 2300 miles it's been driven. On a 102 mile trip last weekend I got an average fuel economy of 62.5 mpg starting with a fully charged Battery and getting 44.7 miles in EV mode.

[Tom,]

Mine showed 2.8 m/kWh when I first got the car back in October. This has gradually dropped and now shows 2.2m/kWh which I put down to the winter use of lights, heaters etc. I would like to know how to reset this display. I get an indicated 40/41 miles range in EV mode. 

My mostly short journeys are always in EV mode with the occasional longer one in hybrid, so the indicated fuel economy is 99.9mpg which doesn't really help.

[Tom,]

Does anyone know how to re-set the m/Kwh display? I don't really want to know the overall average, but more interested in how the figure might improve now I'm no using heaters and lights as much.

[Ivan Earl]

My 450H S+'s best-ever consumption at 90 k/ph was 7.7 L/100km. In Australia, it seems hopeless to set the speed at 110 k/ph, as when the camera sensor sees another vehicle, it automatically slows it. Fuel consumption in that manner varies from 8 to 9 L/100 km. 

[Ken R]

That's my RX450h+ one month old now and 665 miles on the clock. First refuel today with just under quarter of a tank indicated. Ignoring electricity charging consumption was over 82mpg but with the cost of charging (at off peak rate) converted to what that equates to in petrol the overall result is in excess of 62mpg. As expected its down on what I was achieving from my previous NX450h+ (72mpg) but better than I had thought so very pleased.

[Pally]

A bit early for me to comment on ICE as I’ve only had the car for three weeks /248 miles and 92% of driving has been EV so far so I’m showing a rather unsustainable mpg figure still.

m/Kwh has gradually increased from 2.1 when I picked the car up to 2.9.  I’ve comfortably managed a 38 round trip to family in EV mode only and the last trip had 9 miles left when I got back. That may have been helped by being stuck behind a HGV on the way there!

First longer trip tonight of about 150 miles so will be interesting to see the difference using a blend of HV mode on dual carriageways etc and EV at low speed / built up areas rather than just staying in EV mode. I’ll post again once I’ve done a few longer trips and give an idea of the ICE only mpg. 

Are you all in Normal mode or have you switched to Eco? 

 

[Tom,]

David,

Mine is in 'ECO' mode and now showing 2.4 mile/Kwh.

Note that when in EV mode the car will sometimes make up its own mind to change to HV mode for a short time. I think this may be to keep the 12v Battery charged, or perhaps some other reason, but it gives you a false idea of the range you think you are getting in EV mode.

I tried a longer motorway trip recently in HV mode, but the car stayed the whole journey with the ICE engine doing the driving and the fully charged EV Battery stayed fully charged. So I put it into EV mode for the return journey! Electricity is cheaper than petrol!

Tom

[Pally]

Thanks Tom. I’ve checked on the app to see but it only showed the solid ev lines but have heard it will over ride when it needs to for a few reasons. 
 

I’ll see how I get on tonight and back in a few days which will be 300+ miles mainly with ICE. Sounds from what you say that  I’ll have to manually vary it to EV to use the electric range in the right places rather than just use HV mode. Good to know. 

[Ken R]

I've managed 44 miles entirely in EV mode. 

[Xez]

Yesterday I managed to get 43.6 miles of EV driving albeit with 100% charge the car was showing 49.7 miles range as I left…. but then I used the heater, the heated steering wheel and the wipers so all in all pretty good. With the slightly warmer weather my EV economy has improved from 2.6 to 2.7 miles per kWh having now covered 6,200 miles in total.

[Pally]

So first longer drive done. Lexus Link + screenshot attached. 

I used EV mode for the first few miles then HV once on main roads / dual carriageways, then switched to EV again when remaining distance matched EV range . Arrived with just over 2m EV range left.

Overall just under 151 miles of which EV shows as 53.9m.  I presume some of that is the pure EV and the remainder is the standard hybrid, which would give me just under 39 mpg from the ICE / normal hybrid if I allow 38 miles of EV only?  Is that the right way to calc / think about it?

Shame the app doesn’t break it down between pure EV running and the electric mileage that is part of normal hybrid. 
 

[Xez]

Hi David, I’ve been puzzling over the same calculation myself and have ended up with a slightly different outcome from your recent data based upon my methodology. However as with most mathematics it’s not a precise science….

 I would start by subtracting the EV mileage 53.9 from the total mileage of 150.8 giving 96.9 miles

Then using the mpg from the car of 51.8 and dividing this into the total mileage of 150.8 we get 2.91119 gallons used (bearing in mind that the car is probably inaccurate with its calculation).

Then dividing the derived ICE miles of 96.9 by the derived gallons, 2.91119 I get an underlying ICE mpg of 33.3

Please feel free to mark my homework 😉

[Pally]

Hi Xez

Haha. No need for marking, that’s spot on and is exactly how I calculated it as well for ICE only. I was trying to work out what the combined traditional hybrid figure is when the ev only range is exhausted (i.e. under 30% battery)

So I got:

33.3 pure ICE as you say

39 estimate for combined ICE / Battery when operating like a normal hybrid in HV mode - what I’d get if I didn’t plug in. 

51.8 overall for this trip including the additional PHEV EV range. 

Happy to see any suggested variations as just finding my way with this.

Also trying to understand if, aside from the environmental considerations, it is commercially viable to top up at the local charger at 55p per kWh (85p 1st KWh) but suspect that may be outside the spirit of Ken’s thread/post. 

[Tom,]

Is that what they charge at public charge stations? A big difference from the 9p per Kwh I'm paying for 'Octopus Go' each night.

At my indicated 2.4 mile/Kwh I calculate that 33 miles is costing £1.24. At £1.49/litre for petrol, 33 miles of pure ICE only is costing £6.77, which is 5.5 times more.

Even the Octopus daytime rate of 26.778 p/Kwh, it is 1.8 times cheaper than petrol.

[HGUS]

20 minutes ago, Tom, said:

Is that what they charge at public charge stations? A big difference from the 9p per Kwh I'm paying for 'Octopus Go' each night.

At my indicated 2.4 mile/Kwh I calculate that 33 miles is costing £1.24. At £1.49/litre for petrol, 33 miles of pure ICE only is costing £6.77, which is 5.5 times more.

Even the Octopus daytime rate of 26.778 p/Kwh, it is 1.8 times cheaper than petrol.

I maybe doing even better, with Octopus ....

Between 05:30 - 23:30 we pay: 27.94p per kWh
Between 23:30 - 05:30 we pay:  7.50p per kWh 😃 

However, not forgetting, there is also a standing charge of 47.85p per day on top of the above which we have to pay no matter what.

Double However, However, during a sunny 🌞  day the solar panels and associated batteries 🔋 charge the Lexus for FREE, albeit the £1000's I had to pay inadvance for all the install 😟. 
 

[javadude]

13 hours ago, HGUS said:

Double However, However, during a sunny 🌞  day the solar panels and associated batteries 🔋 charge the Lexus for FREE, albeit the £1000's I had to pay inadvance for all the install 😟. 
 

We export our excess solar with Octopus for 15p/kWh and charge the car for 7.5p/kWh overnight. It's only a small saving but over the years it'll add up.

[Tom,]

Interesting John & Chris. I know that Octopus have a somewhat cheaper tariff than 'Octopus GO' which I am on and gives me 9p per unit from 0030 to 0430. However, my understanding is that the 7.5p tariff is only available for those cars whose manufacturers have signed up to Octopus' clever smart arrangement, which Lexus have not.

Chris, I also export excess solar, but am paid 70.71p per Kwh. We were lucky enough to get on original 'feed-in' tariff.

 

[AWC]

4 hours ago, Tom, said:

Interesting John & Chris. I know that Octopus have a somewhat cheaper tariff than 'Octopus GO' which I am on and gives me 9p per unit from 0030 to 0430. However, my understanding is that the 7.5p tariff is only available for those cars whose manufacturers have signed up to Octopus' clever smart arrangement, which Lexus have not.

Chris, I also export excess solar, but am paid 70.71p per Kwh. We were lucky enough to get on original 'feed-in' tariff.

 

You can get on it but you would need to instal an Octopus compatible charger like an Ohme.

[javadude]

5 hours ago, Tom, said:

Interesting John & Chris. I know that Octopus have a somewhat cheaper tariff than 'Octopus GO' which I am on and gives me 9p per unit from 0030 to 0430. However, my understanding is that the 7.5p tariff is only available for those cars whose manufacturers have signed up to Octopus' clever smart arrangement, which Lexus have not.

Chris, I also export excess solar, but am paid 70.71p per Kwh. We were lucky enough to get on original 'feed-in' tariff.

 

🤑That's a very nice export rate.

 

[Alan Thompson]

On 5/3/2024 at 11:59 AM, Pally said:

Hi Xez

Haha. No need for marking, that’s spot on and is exactly how I calculated it as well for ICE only. I was trying to work out what the combined traditional hybrid figure is when the ev only range is exhausted (i.e. under 30% battery)

So I got:

33.3 pure ICE as you say

39 estimate for combined ICE / battery when operating like a normal hybrid in HV mode - what I’d get if I didn’t plug in. 

51.8 overall for this trip including the additional PHEV EV range. 

Happy to see any suggested variations as just finding my way with this.

Also trying to understand if, aside from the environmental considerations, it is commercially viable to top up at the local charger at 55p per kWh (85p 1st KWh) but suspect that may be outside the spirit of Ken’s thread/post. 

Hi Pally

I'm here snooping from the NX Forum - I've got to keep my eye on Ken R !! 😂

Anyway, I've copied and pasted a post from an NX 450h+ Range forum back in 2022 about how I calculate mpg - I do it over a longer time than a single trip though. Hopefully this might help?:

"I filled up on day one (1st March) with odometer showing 29 miles. I've filled up today with odometer showing 3838, not put any fuel in between. Today put in 39 litres (8.58 gallons) to fill again. That works out at 444 miles per gallon.

I am not naive enough to think that this is a true representation, so I thought if I add the cost of the fuel (£65) to the cost of all my electric charges (£255.82), divide that by todays fuel price per litre (£1.669) after converting to gallons, this will provide an equivalent number of gallons to the total cost, then divide miles covered (3809) by the equivalent gallons: 

All fuel cost 65 + 255.82 = £320.82 

Cost per gallon 166.9*4.54609 = £7.587

320.82/7.587 = 42.29 gallons

3809/42.29 = 90.06 mpg

Sits back and waits for those cleverer than me to blow my theory/calculation/premise out of the water.

What have I missed?"

[Ken R]

Welcome to snooping on the RX forum Alan! 😁👍 I trust all good with you and your new NX. Your calculation is spot on as far as I am concerned and exactly how I calculate the overall mpg. Your 90mpg is certainly impressive particularly with only your second refuel in almost 4000 miles!      (Your piling the miles on!) My overall when I had my NX was 72mpg.

First calculation (after 665 miles) on my RX coming in at 62mpg using the same formula although increased temperatures of late are translating to an improving EV range.

 

[Tom,]

Alex - thanks for that. The £1,000 odd cost of an Ohme charger would take a long time to recover at a saving of 1.5p per Kwh! I think I'll stick with the good old 13 amp socket.

One issue I do have is that the Lexus charging programme cannot be set for both start and stop times, which is needed to make full use of the low cost period. I have overcome this by fitting an external 60 amp timer to the 13 amp supply, which I needed to do anyway because I have a heated pool. The pool does not have its own timer and I needed to heat it during the low cost period as well as charge the car.

Tom

[Pally]

10 hours ago, Alan Thompson said:

Hi Pally

I'm here snooping from the NX Forum - I've got to keep my eye on Ken R !! 😂

Anyway, I've copied and pasted a post from an NX 450h+ Range forum back in 2022 about how I calculate mpg - I do it over a longer time than a single trip though. Hopefully this might help?:

"I filled up on day one (1st March) with odometer showing 29 miles. I've filled up today with odometer showing 3838, not put any fuel in between. Today put in 39 litres (8.58 gallons) to fill again. That works out at 444 miles per gallon.

I am not naive enough to think that this is a true representation, so I thought if I add the cost of the fuel (£65) to the cost of all my electric charges (£255.82), divide that by todays fuel price per litre (£1.669) after converting to gallons, this will provide an equivalent number of gallons to the total cost, then divide miles covered (3809) by the equivalent gallons: 

All fuel cost 65 + 255.82 = £320.82 

Cost per gallon 166.9*4.54609 = £7.587

320.82/7.587 = 42.29 gallons

3809/42.29 = 90.06 mpg

Sits back and waits for those cleverer than me to blow my theory/calculation/premise out of the water.

What have I missed?"

That really helpful. Many thanks Alan and makes perfect sense to me. I’m finding it harder to track how much charge the car has taken as I’m having to charge from a 3-pin socket still (curse of a looped supply and lack of response / urgency from SSEN) but guess I can estimate that closely enough with the miles per kw/h and total EV distance and calculating that from my total EV site de driven? 
 

I’ve been disappointed with the app and lack of details it provides. Similarly the bar graphs in the infotainment aren’t particularly informative; so checking the maths with you all is helpful.