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25.4 in Los Angeles, mostly city driving,warm to "soft" weather all year. After 14 months I averaged 25.4 in 2006,1st year owning my 400h,Jan-Dec '06. in SoCal as i said. I think it has helped to change my tire pressure(OEM GoodYear Eagle RS-A) to 34psi...rides better than when the dealership puts them at 30-32...I also don't seem to see much of a difference between city and highway. Actually.... I get better mileage on the highway...like the olden cars of yore! I don't have the roof rack that I didn't like but that hasn't made one bit of difference in the milege either way. It's not why I took it off,of course,but I thought that people that knew I took off the rack might be curious. I think the tire pressure and careful driving did more to improve the mileage than the rackless top. I thought being roof-rackless would make a difference but it really hasn't that I've noticed. Sometimes I enjoy driving more aggressively and that month's "crazy, Dukes of Hazzard" driving, my mileage can drop to the 24s but it has never, ever been less than 24MPG on one tank. I can usually go 400 miles on about 15 or so gallons. Much less MPGs than I was led to believe by the salesman..but then they have to lie or they wouldn't have that kind of job. The car does best when in SoCal traffic but fortunately I am not in it very often. I'm pretty happy and it's way better than my PT Cruiser that was estimated at around 24 and I got 17! Plus after 3 years the automatic transmission was already feeling like I was going over twoXfours during downshifting! Ayayayee! Thank goodness for Lexus and the marvelous cars they make...so, I'll keep this for ten years and at that point my RX400h will still beat anything I've ever had! Just my .02 for what it's worth. happy trails, Rey in L.A.

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We average about 25 MPG with both city and highway (more highway during the weekends and less during the week). I tend to be a more aggressive driver than my wife is and the result is that 25 number that is very consistent over many thousands of miles. By contrast, the three people I know who have RX330s are averaging about 16-17, city and highway. I got a kick out of a recent Car & Driver test of the latest Mercedes Benze SUV. The writer complimented MB from improving the GL-class with the new GL-450. He went on to say, "As a result, the GL's 4.7-liter V-8-one of the smaller engines in the category - delivers fine performance and economy." The hilarious thing is that Car & Driver averaged only 14 MPG. If this is what they call "fine economy", I'd hate to see what horrible economy is!

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I know "RX400h"...., I was a little disappointed at first and then I reminded myself that it's an amazing vehicle, our RX400h, and it weighs well over a solid and safe 4000 lbs.....has power,has every perk shy of slippers and a smoking jacket and it gets over 25 "Real" MPGs! I just don't think the EPA estimates help anyone since they are so off of the "real" life conditions. If they had told me I'd get around 24-27 and then when I got about 26 after my first year of owning this marvel..I'd be ecstatic...but it's the "33 MPG city" banner and the salesman saying in the "right conditions you can get 40"...c'mon now, for Pete's sake...In spurts I have gotten up to 47MPGs...in traffic and coasting a lot...having just reset the computer,etc.....but I would never claim that. I only guage my driving and calculate after every fill up. I don't go by the on board computer because it reads in our favor and it would make me happier to believe it but when I do the simple math, the onboard computer in biased favorably by about .5 or .6 MPG. As I said in a previous post my PT Cruiser was getting 17 MPGs!!! So Nothing in this class and or weight can touch our 400h!... Anyway, that's about it...it seems the average among all of us seems to be between 24-26. Case closed. Lets be happy, 25 is great, and we are helping with the environment...

Happy...ecstatic with my 400h in L.A., Rey

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I average about 27.5 to 28.5 (measured by me, not by the computer -- it says about 29 to 29.5). I have 18k miles. Nearly all of those miles are probably conisidered city. On trips on the highway, I don't get much better than 24 MPG at 70 MPH.

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Wow, 27.5-28.5? That's great! I wonder if there's a difference in gas used in different states. Here in California there are so many cry babies that I believe our gas is more expensive than any other place in the U.S. because of the more stringent fuel laws but I am not sure. I know that when I hear of the national gas prices are one thing,here in L.A they are always around 10-15 cents more than what I hear and we have a lot more people here,stations,competition,etc. I also have heard that there are different seasonal changes as well. Anyone know about this genius concept? In other words every once in a while I hear that the stations are converting to "Summer gas" and then later, "Winter gas". Now, someone please help me get a hold of that. It kind of makes sense though when I let my sarcastic side down, maybe a richer formula for one season or some such thing. I don't trust any of these oil companies or the government people involved with any of this "funny" business. Anyway, good topic and very informative for people wanting to get an RX400h. I wish I had thought to get info this way rather than on the net where even if you get a review,it's from someone that drove the car for a week. Happy trails, Rey Bustos in L.A. 2-07

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We have the '06 model, AWD. I'm thinking that may play into folks numbers. Best tank figured by the MFD was 31.5mpg. Doing the math myself, it calculated out to 32.2mpg (but this was deliberatly driving like an ol' grandpa). Life time average (after 22K miles) is 25.8mpg. My wife drives the 400h most of the time & she REALLY needs to get to that next red light :rolleyes: Still, that's MUCH better than the 12mpg she was getting in the replacement vehicle ... the Range Rover.

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I have a 2006 AWD. I user Premium gas, and have my tire pressure at 36 psi. I got 28.2 during the Summer months, and have gotten 24.9 during the Winter months, so I am averaging around 26.5 overall.

You can improve your mileage results a couple miles per gallon by observing the driving techniques discussed in other posts.

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I have a 2006 AWD. I user Premium gas, and have my tire pressure at 36 psi. I got 28.2 during the Summer months, and have gotten 24.9 during the Winter months, so I am averaging around 26.5 overall.

You can improve your mileage results a couple miles per gallon by observing the driving techniques discussed in other posts.

You might have mentioned it before, but have you noticed any unusual wear on your tires at 36psi? I'm actually running them around there as well but mine still still to new to tell anything yet.

Anyone know if Lexus officially changed this yet?

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I have a 2006 AWD. I user Premium gas, and have my tire pressure at 36 psi. I got 28.2 during the Summer months, and have gotten 24.9 during the Winter months, so I am averaging around 26.5 overall.

You can improve your mileage results a couple miles per gallon by observing the driving techniques discussed in other posts.

You might have mentioned it before, but have you noticed any unusual wear on your tires at 36psi? I'm actually running them around there as well but mine still still to new to tell anything yet.

Anyone know if Lexus officially changed this yet?

I was concerned about running my tires over the recommended pressure until I read the following article. I don't run mine at maximum pressure, but I think I'll get better wear and mileage at 36 psi. I have the Michelin tires, and I don't see any excessive wear. But I am only at 4200 miles.

Here's an article from Officer.com about tire pressure. It presents

a case for using maximum tire pressure. To go to the actual site,

copy the following link, paste it into your browser, and hit Go.

http://www.officer.com/article/article.jsp...19&id=27281

SGT. DAVE STORTON

EVOC Contributor

Officer.com

How many officers check the tire pressure on their patrol car on a

regular basis? We all seem to be great at checking that the lights

and siren work, because the time to find out they don't work is not

when you get a Code 3 call. Likewise, the time to find out your tire

pressure is too low is not when you are in a pursuit and trying to

take a corner at high speed.

What is proper pressure?

The proper tire pressure for the Police Crown Victoria is 44 psi. If

you look on the sidewall of the tire, you will see that it lists 44

psi max pressure. Regardless of what vehicle you have, use the

maximum pressure listed on the sidewall. Higher pressure results in

better performance, decreased tire wear, and it lessens your chance

of hydroplaning at a given speed. This number on the sidewall

lists "the maximum amount of pressure you should ever put in the

tire under normal driving conditions." Pursuits and Code 3 responses

are not "normal driving conditions." Many agencies maintain tire

pressure at 35 psi since this is what is listed in the owner's

manual and on the door placard. The reason the owner's manual lists

35 psi is because we get the same manual as the civilian version of

the Crown Victoria. The police version, however, is fully loaded

with communications equipment, a cage, and your gear. You are not

looking for a soft and cushy ride, you want performance.

Myths about pressure

Let's put to rest some common misconceptions. The tires will not

balloon out creating a peak in the center portion of the tread when

tire pressure is above 35 psi. There is a steel belt that prevents

this from happening. Also, you are not overstressing the tire with

higher pressure, and the tire will not be forced off the rim with

higher pressure. The picture above is Bobby Ore of Bobby Ore

Motorsports driving a Ford Ranger on two wheels. The tires on the

left side have 100 psi in them, and they happen to be tires and rims

from a 1999 Crown Victoria! This is a dramatic example of how

pressure holds the tire in shape, and how much stress a tire can

handle.

Performance

If you were able to watch a tire as it travels across the ground at

high speed, you would see that it deflects to one side during

cornering. The faster you are going through a corner, the more tire

deflection you get. As the tire deflects over onto the sidewall, you

get less traction and more of a tendency to understeer or oversteer.

This could spell disaster when negotiating a corner at high speed

during a pursuit or a Code 3 run. Higher pressure keeps the tire

from deflecting onto the sidewall as much, which keeps more of the

treaded portion on the road.

A good demonstration for EVOC instructors is to have students drive

a high-speed course in a vehicle with 32 to 35 psi. Then have them

run the same course with 44 to 50 psi in the tires. The student will

experience a marked difference in performance. Having officers

experience this difference in vehicle performance is much more

effective than just telling them to check their tire pressure.

Hydroplaning

When a tire rolls across a road covered with water, the tire tread

channels water away so the rubber remains in contact with the road.

The factors that affect hydroplaning are speed, and water depth.

Conventional wisdom says that vehicles will hydroplane in as little

as 1/16th of an inch of water. Not so coincidentally, legal tread

depth is 1/16th of an inch.

Tire manufactures and the Association of Law Enforcement Emergency

Response Trainers International (ALERT) have shown that tires have

more of a tendency to hydroplane when pressure is low. This happens

because the tire footprint (the portion of the tire actually in

contact with the road) is larger. For those of you who water ski,

think of which is easier to get up on: a fat ski or a skinny ski.

More tire surface in contact with the water makes it easier to

hydroplane, just as it is easier to water ski on a fat ski. Also, a

soft tire can be pushed in more by the pressure of the water on the

center portion of the tread. This results in less rubber in contact

with the road.

Tire wear

Much better tire wear results from maintaining proper pressure.

Tires with lower pressure will wear off the outside of the tread

faster from the deflection of the tire during cornering, and the

tires will heat up more from increased road friction. This is one of

the factors that caused the failure of a certain brand of tires on

Ford Explorers some years ago. In 1999 the San Jose Police

Department realized a significant cost savings by increasing the

pressure in the training fleet to 50 psi. They soon followed up by

increasing the pressure in the patrol fleet to 44 psi. For liability

reasons, most agencies are reluctant to exceed the maximum pressure

listed on the tire for actual patrol vehicles, but they reap the

cost saving when going to 50 psi on training vehicles.

Next time you inspect your vehicle, make sure you check your tire

pressure since your ability to performance drive is significantly

affected by it. You are not driving to the store to get a loaf of

bread! You may be called upon to chase a dangerous criminal or

respond to assist another officer in trouble. You don't wonder

whether or not your gun is loaded before you hit the street; don't'

wonder whether your tire pressure is correct once the pursuit

starts. Check your tires routinely, just as you do with all other

critical equipment.

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As I review my RX400h records, I find the following with regard to fuel economy!

  • My current odometer reads approximately 24,400 miles
  • The last fillup yielded 22.15 mpg actual
  • At the last fillup, the indicated MPG was 23.7
  • The average MPG for the last 5 fillups was 22.17
  • The last 5 tanks were Premium unleaded
  • In February 2006, using regular unleaded gasoline the average MPG of the last 5 fillups was 24.13
  • My lifetime-to-date MPG is 22.48!

My opinion is that the electric A/C still has an adverse on fuel economy in that the battery charging has a negative effect on fuel economy.

I'll be commenting on the 'tires' in another forum!

I still like the pep of the RX400h, however, my '98 LS400 has better MPG 'while moving' than the RX400h. The idling engine at stop lights kills it though! It has LOTS of power! The 'MPG' indication is just that.. an indication. I find it consistently showing better than actual!

I try not to let the 'economics' bother me! Based on my findings, I will return to regular unleaded! Why pay 10% more and not have anything to show for it?

Still enjoy the RX400h (although my bride is the primary driver!)

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I can almost guarantee you that if you regularly drive around with your tires inflated to "MAX Pressure", those tires WILL wear out in the center and traction will be compromised. I've done this experiment before and while there is a "sweet spot" of the perct pressure, it is never at the max pressure that is listed on the tires' sidewalls. In the case of the RX400h, I'd have to say that 34-36 PSI is the sweet spot with the OEM tires. This is the pressure with which I will start when I get the Bridgestone tires.

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I drove too carefully my first year,'06, and now I drive with less concern and just enjoy this amazing car and it doesn't seem to matter that much, not enough to be a nervous nellie while driving, what's the point of that,right? I think that now that I have my tires at 34psi, it seems to make a wee bit of difference, haven't had that change for too long so the verdict is still out. It does seem to ride much better than the 30psi that the dealership had them at. Anyway, relax and you'll see that the loss of MPGs isn't enough to ruin your enjoyment of driving an amzing piece of technology. If you want great mileage,get a Prius but,I don't think any of us want that. Rey

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I drove too carefully my first year,'06, and now I drive with less concern and just enjoy this amazing car and it doesn't seem to matter that much, not enough to be a nervous nellie while driving, what's the point of that,right? I think that now that I have my tires at 34psi, it seems to make a wee bit of difference, haven't had that change for too long so the verdict is still out. It does seem to ride much better than the 30psi that the dealership had them at. Anyway, relax and you'll see that the loss of MPGs isn't enough to ruin your enjoyment of driving an amzing piece of technology. If you want great mileage,get a Prius but,I don't think any of us want that. Rey

I was was the dealership the other day and asked about the inflation. They said something like upto 40psi in winter and a few less in summer. I've been running them at ~37 and haven't noticed anything unusual. The higher pressure does help with MPG.

Just wish lexus would actually revise the official recommended pressure.

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I bought my rx400h Jan 1st. Sticker claimed 27-35 mpg. After 2500 miles (I drive a lot) I am getting about 24 mpg.

Anyone getting more?

I drive our 06 very anally & can consistently get 31mpg. But since my wife drives it the most, our average is 25.4mpg over the 18.5K miles total driven since we bought it. In the same vein, the new EPA mileage statistics are out that reflect LOWER mpg for all cars ... seems like I read somewhere about 15% lower on the average. Anyway here's the government's web site:

http://www.fueleconomy.gov/!Removed!/calculatorSelectYear.jsp

You can check you gas guzzler's mileage as well!

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Looks like the (2WD) RX400h drops to 27 city, 25 highway, which is somewhat closer to my numbers. FYI, I raised my tire pressures from 30 to 36 and saw no significant change in fuel mileage.

Tom

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  • 6 months later...

I have approximately 31,000 miles on our 2006 RX400h with a lifetime average of 22.56 mpg! I re-experienced an unexplainable occurrence. Without a lot of elaboration, I have taken the car to the Denver area each of the past two summers and I experienced approximately 3 mpg better gas mileage in the mountains than the flatlands of Texas. I am totally bewildered. I consulted with Denver and Dallas service personnel about 'tweaking' the carburetors like we did in yesteryears for 'mountain' driving. Is there a reverse that's applicable to the 2006 RX400h?? I would have guessed the mountains would be tougher and more glutonous. I keep very accurate records. Yes, I had to use a different gasoline but only because 'mountain regular' was less than the 87 octane we have here in Dallas.

Any comments/suggestions appreciated.

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I have approximately 31,000 miles on our 2006 RX400h with a lifetime average of 22.56 mpg! I re-experienced an unexplainable occurrence. Without a lot of elaboration, I have taken the car to the Denver area each of the past two summers and I experienced approximately 3 mpg better gas mileage in the mountains than the flatlands of Texas. I am totally bewildered. I consulted with Denver and Dallas service personnel about 'tweaking' the carburetors like we did in yesteryears for 'mountain' driving. Is there a reverse that's applicable to the 2006 RX400h?? I would have guessed the mountains would be tougher and more glutonous. I keep very accurate records. Yes, I had to use a different gasoline but only because 'mountain regular' was less than the 87 octane we have here in Dallas.

Any comments/suggestions appreciated.

So what octane are you using in the mountains? 91 at 5300 ft. is like 93 in the flatlands...perhaps you get more mileage because of higher effective octane at altitude. What do you tend to drive when in CO? Short trips around town or highway miles?

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I live in Denver so perhaps we are blessed with the higher altitude but with about 3000 miles on my 2007 400h I am averaging about 28 MPG on 85 octane. I have tried 91 octane a few times but did not see any difference in MPG or performance.

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I was under the impression that higher altitude means less-dense air, which would tend to reduce power and mileage. Perhaps it's the decrease in ambient air temperature that compensates for the lower density?

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