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Getting 19.5MPG on my rx400h :( please help

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Old 06-10-19, 01:59 PM
  #61  
professorm
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Originally Posted by mnewxcv
might want to check tire pressure, 24 mixed is a tad low. I get about 24 in the winter with mostly highway driving, but closer to 27 in the summer with more city mixed in.
Tire pressure is good at 33 psi. The 2006 owners manual calls for regular gas, so I use regular in it.
Old 06-10-19, 08:52 PM
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TommyTT
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I run 38 psi f/r for longer tire life and less rolling resistance
Old 06-18-19, 02:06 PM
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myw
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Originally Posted by TommyTT
I run 38 psi f/r for longer tire life and less rolling resistance
same here - i also get 9.8 L/100km == 24mpg on avg (summer months, maybe a little better if its more hybrid style city driving and worse milage during freezing cold winters). both my rx400h's have performed equally in this regard.
Old 06-18-19, 02:08 PM
  #64  
myw
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wow! impressive.

Originally Posted by TommyTT
My wife recently did a 818 mile round trip from SE AZ to the Hopi Res and got 29.9 mpg. And trip was in mountains 40%. 2008 RX400h. With 134,250 miles on clock.
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Geemaan (07-09-21)
Old 06-18-19, 03:25 PM
  #65  
mnewxcv
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I am at 27.4 for the past 1100 miles. Mostly highway with cruise set to 65.
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Old 07-09-21, 02:19 PM
  #66  
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Me too. 14.2 to 14.5 max
Old 07-09-21, 02:25 PM
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WolfyLS460
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Originally Posted by Geemaan
Me too. 14.2 to 14.5 max
I think it's because of the aging hybrid battery. Mine has over 200k mi and I'm only getting 22mpg in the city but 28-30 on freeway....no different than a regular non-hybrid.
Old 07-09-21, 02:55 PM
  #68  
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People were saying they can fill 17.2 Gallons and I mentioned I am not able to fill more than 14.2 to 14.5 max. Think it is so hot here in AZ like 110+ and the fuel tank has gas which trips the gas pump hose which operates on the simple principle of pressure equalizing and stopping the fill.

Regarding gas mileage
Get like what you said 21 in city and think I need to combine more trips and shorter trips like 2 to 10 miles kills the mileage average.
Since the initial miles are 7 to 9 mpg. Further living in AZ the temps are 110 and even if the car is inside the garage it is hot as hell and Black with Black does not help.

Not sure if anyone has played with Regen braking or it is controlled by car computer and PCB. If it can be varied for city and highway driving's and reduce coasting in city with more regen we can get better mileage
I had a Prius and the regen braking was much better and I was able to get great car mileage like 43 to 45 sometimes even 47.
Not sure if other forum members have played with it and may post this question
Old 07-09-21, 04:09 PM
  #69  
iMSQ
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Originally Posted by Geemaan
People were saying they can fill 17.2 Gallons and I mentioned I am not able to fill more than 14.2 to 14.5 max. Think it is so hot here in AZ like 110+ and the fuel tank has gas which trips the gas pump hose which operates on the simple principle of pressure equalizing and stopping the fill.

....
RX330/350 and RX400h have different tank capacities (19 vs 17)
https://www.clublexus.com/forums/rx-...ml#post1813921
https://www.clublexus.com/forums/rx-...l#post10929162
Old 07-21-21, 09:41 AM
  #70  
nehal51086
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To start I'll be honest I didn't read the entire thread...just skimmed a few here and there.....thought I'd share my current mpgs.

I have an 07 as my daily driver currently for the last 2 years or so. I am currently getting 26 mpgs over the last 2600 or so miles.

Facts to mention.
1. I do not try to hypermile at all besides when driving at low enough speeds to use just the electric motor, at which point I'll try to keep it that way..
2. I just about use every horse power I can as often as I can....(I came from a GSF, ill just leave jt at that..lol)
3. I have a K&N drop in air filter ...put in very soon after the current trip was reset...maybe 100 or 200 miles into that 2600 figure stared above.
4.im usually by myself.
5. About 60-75% highway miles.
6. Not sure if it's a factor, but have like 200lbs of tools in the trunk.
7. I did try one of the plug in "chips" that claim to increase hp and mpgs....which was installed when trip was reset, and is still installed.


Prior to reset it was like 24.5mpg....increase most likely was the new filter, took out an kn filter that was a few years old....I didn't bother washing as it was a bit damaged from being put in backwards....so not sure how much the chip helped
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Old 11-18-21, 01:00 PM
  #71  
Amoah
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Hello Guys,

I have a Lexus RX 400h, it has about 141,000 miles on it. I get about 23.6 mpg on it. It keeps improving the longer I drive. I am however experiencing very bad mileage when I do the math. So a full tank takes me about 270 miles. For a 17.2 gallon car, it actually means I am getting about 15 mpg, which is awful and strange at the same time. Has anyone experienced anything like this?
Old 11-18-21, 01:09 PM
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WolfyLS460
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My 217k mi RX400h is getting better mpg on open freeways than in city driving... 30 and 20mpg, respectively.
I chalked it up to an old dying hybrid battery.
Just replaced timing chain, spark plugs, fixed leaking valve cover gasket, etc...should be good till 300k mi if the old battery doesn't die.
Old 11-18-21, 02:44 PM
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professorm
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Originally Posted by Amoah
Hello Guys,

I have a Lexus RX 400h, it has about 141,000 miles on it. I get about 23.6 mpg on it. It keeps improving the longer I drive. I am however experiencing very bad mileage when I do the math. So a full tank takes me about 270 miles. For a 17.2 gallon car, it actually means I am getting about 15 mpg, which is awful and strange at the same time. Has anyone experienced anything like this?
i question your calculation method because you quote the tank size. It doesn’t matter the tank size. You should be calculating the gallons it take to fill the tank to the first click on the gas pump. You should not ‘top up’ the tank where you keep clicking it after the first gas pump click, unless you are legitimately sure that the pump click is defective.

easiest method is to use a gas tracking app and be consistent. I use Fuelly. Sometimes I do get a single fluke measurement where a really good fuel economy follows a really bad one. In data analytics, you throw out or average extreme values.
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Old 11-18-21, 02:46 PM
  #74  
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Originally Posted by WolfyLS460
My 217k mi RX400h is getting better mpg on open freeways than in city driving... 30 and 20mpg, respectively.
I chalked it up to an old dying hybrid battery.
Just replaced timing chain, spark plugs, fixed leaking valve cover gasket, etc...should be good till 300k mi if the old battery doesn't die.
did you do the 200k mile tune up yourself or did you pay a shop? Mine is due soon and I’m trying to decide.
Old 11-18-21, 03:28 PM
  #75  
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Originally Posted by Amoah
Hello Guys,

I have a Lexus RX 400h, it has about 141,000 miles on it. I get about 23.6 mpg on it. It keeps improving the longer I drive. I am however experiencing very bad mileage when I do the math. So a full tank takes me about 270 miles. For a 17.2 gallon car, it actually means I am getting about 15 mpg, which is awful and strange at the same time. Has anyone experienced anything like this?
1. What is your driving style?
2. Test your battery
https://www.clublexus.com/forums/rx-...l#post11120000

PS: When "refuel" light is ON then you have 3 more gallons in gas tank.


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