New rx400h owner. Mpg not good. Cold weather?

[sorcerer]

1 hour ago, cachaciero said:

I have taken the same logic to the RX and run with 5 psi more in each tyre than recommended I mention that because all my mileage figures quoted would have been achieved with these tyre pressures.

Nothing to do with me, but be very careful about doing that. I've mentioned it on these forums before but just to reiterate - I used to work with someone who had an accident and on investigation they found that he had incorrect tyre pressures. I can't remember if his insurance refused the claim altogether or if they paid out a reduced sum, but it was definitely one or the other.

[T Sport 1978]

I run mine at 40psi, during summer I would average 33mpg, but this month since becoming cold, I have averaged 29.9mpg so far.  

I used to get the same pattern of economy degradation with a Toyota Hybrid (Auris), it's just how the Toyota Hybrid behaves.  Cold temperature is not our friend.  

Considering it's a 3.5 V6 and a hell of a hevalump, I don't think it's too bad at all.  I used to get about 30mpg on average in a 2.4 Accord all year round, now that was a fun engine.

[royoftherovers]

40 psi when cold rises by 3+ to 44/45 when warm and that seems to me to be excessive and dangerous. Be careful

9 hours ago, T Sport 1978 said:

I run mine at 40psi, during summer I would average 33mpg, but this month since becoming cold, I have averaged 29.9mpg so far.  

I used to get the same pattern of economy degradation with a Toyota Hybrid (Auris), it's just how the Toyota Hybrid behaves.  Cold temperature is not our friend.  

Considering it's a 3.5 V6 and a hell of a hevalump, I don't think it's too bad at all.  I used to get about 30mpg on average in a 2.4 Accord all year round, now that was a fun engine.

 Des.

 

Regards

John

[ISJason]

I was thinking that the ICE was the in car entertainment system myself ?. I wasconfused LOL. Also , don't forget you're dealing with old technology in the RX 400 I think technology and the software has moved on from that especially in the later models.

Sent from my iPad using Tapatalk

[NemesisUK]

21 hours ago, Glover said:

Thanks Nemesis, that makes perfect sense. Mine sometimes shows an almost full battery and then will cut in when I'm doing slow speed manoeuvring but at other times will stay on electric when it's showing two purple bars and I'm doing over 30!  But the technology is amazing; this is my first hybrid and although I know when it's cutting in at very slow speeds, once its going it's so seamless and quiet that unless I have the energy monitor on accelerating hard I struggle to identify what motor is working.  Lexus certainly know how to build cars.

My experience precisely! I'm still baffled as to why, as you say, the ICE cuts in or not seemingly irrespective of Battery level/throttle position. Possibly due to ambient and/or engine temp and a/c requirements?

Agree, unless I see the EV indicator the switch between ICE and electric is undetectable. Toyota have refined their hybrid technology very well and Lexus have integrated it well into their cars. 😎

[royoftherovers]

ICE = internal combustion engine ?

If the first poster (Chris ?) had made this clear it would have been helpful.

Regards

John

[T Sport 1978]

6 hours ago, NemesisUK said:

My experience precisely! I'm still baffled as to why, as you say, the ICE cuts in or not seemingly irrespective of battery level/throttle position. Possibly due to ambient and/or engine temp and a/c requirements?

Agree, unless I see the EV indicator the switch between ICE and electric is undetectable. Toyota have refined their hybrid technology very well and Lexus have integrated it well into their cars. 😎

It depends on your climate control settings i.e temperature set to need heat from engine.  Your ICE will cut in at every opportunity if your climate control requires the heat.

Also, I find the Battery power alone is capable of pretty impressive cruising speed (not for acceleration), it will cruise happily at nearly 50mph on Battery alone.  Which I find amazing.

[ISJason]

I always notice a drop in mpg when It's cold weather. In the summer I was getting 30 to 31 mpg.. now in this cold weather it's gone down to 25mpg. It's always had that characteristic since I had it.

Sent from my iPad using Tapatalk

[veritas200700]

On 12/11/2016 at 1:55 PM, Assa1974 said:

When I first got my car last Easter I was dissaponted with the fuel consumption and didn't feel the batteries were doing their job. After a bit of research I found that you could 'reset' the battery levels and control system. After that there was a definite improvement in the mpg and only a couple of weeks ago I achieved my best ever run of an indicated 34.7mpg over my 100 mile journey to work. My conclusion is that by far the biggest factor impacting fuel consumption is my right foot and it's taken a concerted effort to alter my driving style to achieve what I would term 'reasonable' economy.

Hey There

can you please advise how I can do the reset?

 Thanks 

[Assa1974]

On 13/12/2016 at 2:57 PM, veritas200700 said:

Hey There

can you please advise how I can do the reset?

 Thanks 

It's a little bit of a faff TBH. If you do a google search you should find plenty of advice and I'd suggest you do that even if just to verify what I've posted below. This is a procedure I picked up myself doing just that. I can't promise what results you will get but it seemed to give me an immediate improvement even if it was only a couple of MPG on a long drive.

1) Make sure the vehicle is fully warmed up. Do the procedure immediately following a long drive that runs the engine (highway speeds are best - not long gliding stealth runs at low speeds with the engine off). This will insure the coolant temp is at FULL operating temperature - it is not necessary to actually measure the coolant temperature if you warm up the engine sufficiently and don't let the engine shut down too long and cool off before doing the procedure.

2) With the vehicle stopped and in drive, press firmly on the brake to keep the vehicle from moving and then step on the accelerator while watching the power meter (to the left of the speedometer). Press down on the accelerator to keep the needle between 1/2 and 3/4 up the scale. You will find that the engine management system will automatically limit the engine load no matter how far you press down on the pedal so the amount you press is not critical as long as it is either 1/2 scale or to the engine's self-limiting load value. Keep the engine loaded for a full 30 seconds but not longer than 40 seconds (this procedure brings the hybrid Battery up to a maximum state of charge - if you watch the Battery symbol, you willl see it tick up to a "full" display).

3) Shut off the engine and place it in park

4) Wait 5 seconds.

5) Turn the ignition key back on to display "ready"

6) make sure the A/C and heater system controls are set to off

7) Lightly step on the accelerator pedal until the engine starts -then immediately take your foot off the accelerator and let the engine run until it stops by itself.

This completes the procedure.

 

[Bazzaar]

Big thanks to JBPRX400h for the link.  Just bought a lexus and love it but at 21 mpg, I was thinking this is not right.  Did ISC Learning Procedure and drove for about 20 miles.  Now doing 38 mpg.  Keep up the good work all.

[JBPRX400h]

Glad it worked for you.

Happy New Year!

JBP