Rx400h Not Up To Specs

[the-headless_horseman]

Yeah,

I'm beginning to think I need to get this puppy on the highway and drive it a few hundred miles to realliy 'open it up.' The gas motor needs to loosen up a little and I am aware that short trips aren't the best gauge for mileage...

I will take the car next weekend on the open road and test several speeds on cruise for efficiency....I'll then report the numbers here for all to see...

I fully EXPECT to be breaking 26 mpg at the lower highway speeds...55/60 mph...I just hope I don't fall asleep as the car is quite comfortable!

BTW, Patt, the link you sent me said that most cars do not get their best efficiency until 3-5k miles...that's quite a distance....and quite a way to improve mileage...I'd like to see improvements regardless of driving types during this time!

Headless

[bartkat]

I dunno what the cd is for a 400h, but that's usually a problem with SUV's at speeds above 55 MPH.

[cosimoto]

Hello all --

I've had my 400h for about 10 days now. I also have a Prius, which is about 15 months old. I can tell for certain that there is a break-in period and that after about 6 months (about 8K miles) the fuel effeciency began to steadily creep up. When I first got the car, I was getting 35-39 MPG. Now, we routinely get in the mid to high 40's.

I'm currently getting about 25 miles a gallon in my 400h. I'm on my second tank, and I've already seen an improvement as I got 22 MPG on the first tank. I expect that my experience with the Prius will be the same with the Lexus as they both use exactly the same technology. So for all of you that are dissatisfied with your MPG so far, I would say hang in there for at least another 2K miles or so. And yes, you will have to adjust your driving habits if you have a "heavy" foot in order to get the best mileage. But that would hold true whether you were driving a hybrid or an 18 wheeler.

[the-headless_horseman]

Although I doubt in one fillup you are going to go from 22 to 25 mpg, I do appreciate your certainty regarding better mileage over time...(probably your driving style contributed more to your improved numbers)

The RX has a more advanced hybrid system as compared to the Prius, so I expect that it should get better with time as wel, if not even moreso (% wise)l...it's just tough to drive it off the lot and get such low mileage when the darn sticker says it'll do much better...

If the trend with the Prius is a nice long breakin, then I have no problem with a breakin for the RX...as far as changing driving habits, I can do that, to a point...I still want to enjoy driving, and timing my coasting with every acceleration doesn't really cut it for me...however, a little compromise is in order, and I'm fine with that...

If I could end up with over 25 mpg combined given some time, while actually enjoying driving, I'll be praising this car to everyone...however, if it stays in the low 20s, you can be sure I won't be a Lexus proponent...so far, I contain my sentiments to this and like boards...

Headless

[RX in NC]

Tom and Ray Magliozzi's "Car Talk" column this week provides a logical and easy-to-understand explanation of why hybrid vehicles will never achieve the high-mileage figures that their manufacturers love to advertise.

To read the column, check the Automotive section in your major local newspaper or go to their website at www.cartalk.com.

[SW03ES]

headless- I think what you're experiencing is buyers remorse. Do yourself a favor and just wait, the mileage will improve over time if the vehicle is anything like the Prius.

As for the FX35...the RX400h is significantly quicker than the FX35, more along the lines of the FX45.

[blake918]

No $2000 tax credit...it's a $1000 tax credit for 2005, last I looked...

←

Here's what I found on the IRS's site:

"Under the Working Families Tax Relief Act of 2004, the deduction amount is limited to $2,000 for cars first put into use in 2004 and 2005. the deduction will be limited to $500 for vehicles placed in service in 2006, and no deduction will be allowed after that year."

Here's the link for further info: http://www.irs.gov/newsroom/article/0,,id=107766,00.html

Achieving EPA gas mileage on any car is determined by how hard your right foot comes down. In the city, I can make my 95 LS400 get 15mpg or 21mpg; hwy is based on how constant my speed is held. My city mileage is only achieved by my very marginal use of the gas from red lights/stop signs-marginal as in no acceleration past 2,000rpms. It sounds slow, but it's really not at all since the V8 has such a good power band. EPA gives a city average of 18 for my LS, but I get 21mpg because of my slower acceleration. When I'm on the road 25k miles a year, it's worth it.

I agree with the others-I wouldn't cast judgement until atleast 1k or 2k. ;)

[the-headless_horseman]

headless- I think what you're experiencing is buyers remorse. Do yourself a favor and just wait, the mileage will improve over time if the vehicle is anything like the Prius.

As for the FX35...the RX400h is significantly quicker than the FX35, more along the lines of the FX45.

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Buyer's remorse, eh????

I don't think so...just adjusting to numbers not (yet) meeting expectations...

Other than this issue, I love the car...it is quick (carefully though) and has tons of cool features...I'm sure I'll get years and years of quality use out of it...

I'm just bickering over the mileage numbers cause I really wanted to see those great numbers right off the bat...

Today alone I discovered how to drive 'older'...didn't tailgate, coasted more, and tried to time accelerations...mileage went up .5 to 22.9...23.0...I'm trying guys/gals...honest...

I do think for those of you getting near 30 with normal road and highway use that your vehicle is tuned differently!!!???

Headless

[patt]

We have gotten the results from our first fill up. We got just over 25 miles per gallon. That is about what I expected giving running some accessories. We have had some sunny days here where the air conditioning has come on too.

That is about what I expected to be getting so I'm pretty happy to be at that level this early.

[the-headless_horseman]

We  have gotten the results from our first fill up. We got just over 25 miles per gallon. That is about what I expected giving running some accessories. We have had some sunny days here where the air conditioning has come on too.

That is about what I expected to be getting so I'm pretty happy to be at that level this early.

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My system read 24 mpg at my first fill-up...but it was really 23.4...perhaps I filled up more than dealer, but still numbers a little low...

Right now I'm trying hard to get to 23...and keep it there...still shorter drives though...

Perhaps with more time it'll get up and over 25...I don't expect this vehicle to ever get over 26 on 'normal' driving for me...time will tell, I guess...

Headless

[ReXus]

Four days and 180 miles after delivery, I'm seeing 23-24 mpg in mixed city/highway driving. Still, it beats 14-16 on my last SUV so I'm happy for now.

It's been a long time since I've gone this long without waiting on line at a gas station. I see in the owner's manual that they recommend 87 octane (or 91 for "better performance"). That'll save me 20 cents a gallon too!

[marmadmax]

It is now official - 400h has been approved by IRS for tax deduction as of 5/6/2005.

"05/06/2005 Torrance, CA

May 6, 2005 - - Lexus announced today that it had received official notification from the Internal Revenue Service (IRS) that the 2006 model year RX 400h is certified for a clean-burning fuel deduction. This certification means that taxpayers who purchase a new RX 400h during calendar year 2005 may claim a tax deduction of up to $2,000 on Form 1040.

'Lexus RX 400h purchasers can use or take this certification to their individual tax advisors to determine how they can take full advantage of this important federal tax benefit,' said Bob Carter, Lexus group vice president and general manager. "

[SW03ES]

Buyer's remorse, eh????

I don't think so...just adjusting to numbers not (yet) meeting expectations...

Other than this issue, I love the car...it is quick (carefully though) and has tons of cool features...I'm sure I'll get years and years of quality use out of it...

I'm just bickering over the mileage numbers cause I really wanted to see those great numbers right off the bat...

Today alone I discovered how to drive 'older'...didn't tailgate, coasted more, and tried to time accelerations...mileage went up .5 to 22.9...23.0...I'm trying guys/gals...honest...

Headless

←

Well, that is the definition of buyers remourse. You bought something, its not what you expected, and its made you remourseful...buyers remorse.

As to the mileage. Like I've said many times before...

Give

It

Time

We were dissapointed with the mileage on our Prius for 8 months, even bringing it in to see if something was wrong with it. Now it gets 48MPG, and I know why as I followed my fiance down to my office today. She drives like a crazy person. I bet I could get 55 with it.

[RX400h]

Buyer's remorse, eh????

I don't think so...just adjusting to numbers not (yet) meeting expectations...

Other than this issue, I love the car...it is quick (carefully though) and has tons of cool features...I'm sure I'll get years and years of quality use out of it...

I'm just bickering over the mileage numbers cause I really wanted to see those great numbers right off the bat...

Today alone I discovered how to drive 'older'...didn't tailgate, coasted more, and tried to time accelerations...mileage went up .5 to 22.9...23.0...I'm trying guys/gals...honest...

Headless

←

Well, that is the definition of buyers remourse. You bought something, its not what you expected, and its made you remourseful...buyers remorse.

As to the mileage. Like I've said many times before...

Give

It

Time

We were dissapointed with the mileage on our Prius for 8 months, even bringing it in to see if something was wrong with it. Now it gets 48MPG, and I know why as I followed my fiance down to my office today. She drives like a crazy person. I bet I could get 55 with it.

←

Here are some "Real World" figures for more vehicles from Popular Mechanics:

Toyota Scion XB: Worst milage = 19.6, Best = 34.3, Avg = 27.2

Now, keep in mind that this is a light, 4-cylinder econobox that is not anything close to being fast!

Nissan Titan SE: Worst milage = 11.7, Best = 16.8, Avg = 15.5

Sure, this is a V8 truck, but look at how low some new vehicles' gas mileage is getting!

Mercedes Benz E500 4matic: Worst milage = 12.8, Best = 23.9, Avg = 17.3

The RX400h is looking better all the time, now isn't it?

[the-headless_horseman]

Okay everyone...

Here's what I got!!!

I drove my RX400h over 1000 miles this weekend...from MD to SC and back...

I averaged about 27.1 mpg going down as I hit traffic in DC and Northern VA...in traffic, the mileage was great as I was able to coast around on the electric...however, the gas motor did kick on when the electric battery was drained enough...this took about 1 mpg off the avg. before it shut off again...I was not using air or heavy battery drain accessories...

When I filled up, my manual calculations showed 27.1...the computer said 27.2...

While driving around in slower terrority with 35-50 mph limits, I averaged in low 25s...when you accelerate from stop and have to get up to speed more quickly, it does adversely affect your mileage...

On the ride home, I was at 24.1 for the first 150 miles...don't know why...oh yeah, had air conditioning on...so, figure that takes a little over 1 mpg away...

The rest of the trip I averaged a little over 27...got as high as 33.1 when in traffic again around Fredericksburg, VA...big accident apparently and lots of traffic...

So, I am a converted man...I see the vehicle can do the mileage as stated and I just needed to use it a lot more...

BTW...speeds...at 60 mph, you'll get about 28.4 mpg...65 mph you'll get around 27 mpg...at 70 mph, you'll get in mid 25s...at 75-80 mph, you'll get in upper 24s...I had over a 1000 miles to test this, so you can be sure the range is somewhere around this...

Headless

[RX400hGirl]

Okay everyone...

Here's what I got!!!

I drove my RX400h over 1000 miles this weekend...from MD to SC and back...

I averaged about 27.1 mpg going down as I hit traffic in DC and Northern VA...in traffic, the mileage was great as I was able to coast around on the electric...however, the gas motor did kick on when the electric battery was drained enough...this took about 1 mpg off the avg. before it shut off again...I was not using air or heavy battery drain accessories...

When I filled up, my manual calculations showed 27.1...the computer said 27.2...

While driving around in slower terrority with 35-50 mph limits, I averaged in low 25s...when you accelerate from stop and have to get up to speed more quickly, it does adversely affect your mileage...

On the ride home, I was at 24.1 for the first 150 miles...don't know why...oh yeah, had air conditioning on...so, figure that takes a little over 1 mpg away...

The rest of the trip I averaged a little over 27...got as high as 33.1 when in traffic again around Fredericksburg, VA...big accident apparently and lots of traffic...

So, I am a converted man...I see the vehicle can do the mileage as stated and I just needed to use it a lot more...

BTW...speeds...at 60 mph, you'll get about 28.4 mpg...65 mph you'll get around 27 mpg...at 70 mph, you'll get in mid 25s...at 75-80 mph, you'll get in upper 24s...I had over a 1000 miles to test this, so you can be sure the range is somewhere around this...

Headless

←

YAY HH! I was hoping you'd start to see some good numbers :D I'm still tracking at 29-30 mpg but I think it's b/c I'm constantly in stop and go traffic :cries:

[RX400h]

Okay everyone...

Here's what I got!!!

I drove my RX400h over 1000 miles this weekend...from MD to SC and back...

I averaged about 27.1 mpg going down as I hit traffic in DC and Northern VA...in traffic, the mileage was great as I was able to coast around on the electric...however, the gas motor did kick on when the electric battery was drained enough...this took about 1 mpg off the avg. before it shut off again...I was not using air or heavy battery drain accessories...

When I filled up, my manual calculations showed 27.1...the computer said 27.2...

While driving around in slower terrority with 35-50 mph limits, I averaged in low 25s...when you accelerate from stop and have to get up to speed more quickly, it does adversely affect your mileage...

On the ride home, I was at 24.1 for the first 150 miles...don't know why...oh yeah, had air conditioning on...so, figure that takes a little over 1 mpg away...

The rest of the trip I averaged a little over 27...got as high as 33.1 when in traffic again around Fredericksburg, VA...big accident apparently and lots of traffic...

So, I am a converted man...I see the vehicle can do the mileage as stated and I just needed to use it a lot more...

BTW...speeds...at 60 mph, you'll get about 28.4 mpg...65 mph you'll get around 27 mpg...at 70 mph, you'll get in mid 25s...at 75-80 mph, you'll get in upper 24s...I had over a 1000 miles to test this, so you can be sure the range is somewhere around this...

Headless

←

FANTASTIC NEWS! You are getting the same mileage as a Toyota Scion XB econobox!

[SW03ES]

Yep, and it will continue to improve as time goes on.

[VGR]

FANTASTIC NEWS! You are getting the same mileage as a Toyota Scion XB econobox! 

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...60 mph, you'll get about 28.4 mpg

...65 mph you'll get around 27 mpg

...at 70 mph, you'll get in mid 25s

...at 75-80 mph, you'll get in upper 24s

Actually, these figures for the RX400h are significantly worse than what a Camry 4 cylinder can do. A Camry 4 cylinder gets (based on almost a dozen I have rented and driven thousands of miles):

...60 mph, about 34 mpg

...65 mph about 32.5 mpg

...70 mph, about 31 mpg

...75-80 mph, about 29 mpg

The Toyota Highlander is about the same size vehicle as the RX400h and is available with the Camry 4 cylinder engine and so probably gets the same or a little better gas mileage than the RX400h. A 4 cylinder Highlander can only accelerate 0-60 in 10.5 - 11.0 seconds, so the RX400h is alot more powerful.

[patt]

...60 mph, about 34 mpg

...65 mph about 32.5 mpg

...70 mph, about 31 mpg

...75-80 mph, about 29 mpg

The Toyota Highlander is about the same size vehicle as the RX400h and is available with the Camry 4 cylinder engine and so probably gets the same or a little better gas mileage than the RX400h.  A 4 cylinder Highlander can only accelerate 0-60 in 10.5 - 11.0 seconds, so the RX400h is alot more powerful.

←

You might think that, but the Highlander pays a significant price in mileage for its larger size especially on the highway numbers where drag is so important. Going from 2WD to 4WD carries an additional penalty.

The EPA site for the 2004 Camry and Highlander 4 cylinder shows city/highway/combined:

Camry 24/33/27

Highlander 2WD 22/27/24

Highlander 4WD 21/25/22

I drove the Camry 4 cylinder before I bought my Camry 6 cylinder. IMO, it was a bit underpowered. The Highlander especially at highway speeds must be more so. I wonder how many of them are actually sold that way.

If one is worried about the environment, then one would also be concerned about the EPA scores. The 4 cylinder Camry has scores of 6 and 7. The Highlanders for some reason are much worse with scores of 1 and 2. The RX400H is SUELV which makes it better than the Camry which is ULEV. I'm not sure what that equates to on their 0 to 10 score.

[RX400h]

FANTASTIC NEWS! You are getting the same mileage as a Toyota Scion XB econobox! 

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...60 mph, you'll get about 28.4 mpg

...65 mph you'll get around 27 mpg

...at 70 mph, you'll get in mid 25s

...at 75-80 mph, you'll get in upper 24s

Actually, these figures for the RX400h are significantly worse than what a Camry 4 cylinder can do. A Camry 4 cylinder gets (based on almost a dozen I have rented and driven thousands of miles):

...60 mph, about 34 mpg

...65 mph about 32.5 mpg

...70 mph, about 31 mpg

...75-80 mph, about 29 mpg

The Toyota Highlander is about the same size vehicle as the RX400h and is available with the Camry 4 cylinder engine and so probably gets the same or a little better gas mileage than the RX400h. A 4 cylinder Highlander can only accelerate 0-60 in 10.5 - 11.0 seconds, so the RX400h is alot more powerful.

←

Comparing highway mileage figures is not what true hybrids are all about. The Honda Accord hybrid gets great highway milage because of cylinder deactivation. However, its city milage is not as high as that of the RX400h. I think it's safe to say that most of us see a fair amount of daily traffic and this is where the RX400h trounces any other SUV its size.

[the-headless_horseman]

FANTASTIC NEWS! You are getting the same mileage as a Toyota Scion XB econobox! 

←

...60 mph, you'll get about 28.4 mpg

...65 mph you'll get around 27 mpg

...at 70 mph, you'll get in mid 25s

...at 75-80 mph, you'll get in upper 24s

Actually, these figures for the RX400h are significantly worse than what a Camry 4 cylinder can do. A Camry 4 cylinder gets (based on almost a dozen I have rented and driven thousands of miles):

...60 mph, about 34 mpg

...65 mph about 32.5 mpg

...70 mph, about 31 mpg

...75-80 mph, about 29 mpg

The Toyota Highlander is about the same size vehicle as the RX400h and is available with the Camry 4 cylinder engine and so probably gets the same or a little better gas mileage than the RX400h. A 4 cylinder Highlander can only accelerate 0-60 in 10.5 - 11.0 seconds, so the RX400h is alot more powerful.

←

I don't think there's much comparison between a 4-cylinder highlander and the RX400h...in appeal, performance, and/or luxury...

Sure, the highlander might do better on the highway, but it won't do better in heavy traffic..

Plus, the RX has amenities that the highlander doesn't have...I'd also have to worry coming off a short ramp onto the highway as the highlander doesn't accelerate quickly and it could get you in trouble...

The hybrid Highlander will be a good choice...a lot more money than a standard highlander, but the best of both worlds...basically, a RX400h with less amenities...but the engine will be the same, and that's a good thing!

Headless

[motion]

Contrary to others, I'm getting much worse fuel economy during city driving. Maybe it's because of short trips. Maybe just still breaking in. I have noticed the numbers go up since I've learned to drive her differently, but still not breaking 25.

The whole concept of city driving fuel performance doesn't seem to be working for me because the engine wants to barge in on my party at 10MPH. I have noticed that at times this speed range can increase to 20ish. Perhaps due to warming up, perhaps battery charge, not sure.

If anyone has any suggestions on increasing my city MPG I'd like to hear them.

I seem to have adopted a new driving style, that I'm getting used to. I use the gas pedal delicately. It's kind of like petting a pit bull: stroke it lightly and back off as soon as she starts to growl.

[the-headless_horseman]

Contrary to others, I'm getting much worse fuel economy during city driving.  Maybe it's because of short trips.  Maybe just still breaking in.  I have noticed the numbers go up since I've learned to drive her differently, but still not breaking 25.

The whole concept of city driving fuel performance doesn't seem to be working for me because the engine wants to barge in on my party at 10MPH.  I have noticed that at times this speed range can increase to 20ish.  Perhaps due to warming up, perhaps battery charge, not sure.

If anyone has any suggestions on increasing my city MPG I'd like to hear them.

I seem to have adopted a new driving style, that I'm getting used to.  I use the gas pedal delicately.  It's kind of like petting a pit bull:  stroke it lightly and back off as soon as she starts to growl.

←

I have found that warming up the vehicle is crucial...being the car does not idle, this would entail driving over 10 minutes at a time...

My drive to work is about 10 minutes, so I end up with about 25 mpg now...however, on my 1000+ mile trip over the weekend, I could be coasting at 20 mph, hit the acceleration a bit and only electric would kick in...

From a standstill, if you're going to get 'up to speed' at like 35 or 45, you're gonna pay for it...however, in stop and go traffic, the little accelerations to keep up with the car in front of you will be made with electric, and this is where your mileage will be very good!

Just remember that even in stop and go, the battery will run down in 15 minutes, and the gas will kick on...no matter what you do...the battery has to keep a certain amount of charge...

Headless

[patt]

Contrary to others, I'm getting much worse fuel economy during city driving.  Maybe it's because of short trips.  Maybe just still breaking in.  I have noticed the numbers go up since I've learned to drive her differently, but still not breaking 25.

The whole concept of city driving fuel performance doesn't seem to be working for me because the engine wants to barge in on my party at 10MPH.  I have noticed that at times this speed range can increase to 20ish.  Perhaps due to warming up, perhaps battery charge, not sure.

If anyone has any suggestions on increasing my city MPG I'd like to hear them.

I seem to have adopted a new driving style, that I'm getting used to.  I use the gas pedal delicately.  It's kind of like petting a pit bull:  stroke it lightly and back off as soon as she starts to growl.

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Motion, From my experience so far, I don't see any mpg advantage from doing painfully slow starts. In addition, I can't come up with any logical that painfully slow starts are more efficient than a normal gentle acceleration. Of course, jack rabbit starts waste energy due to extra friction/slippage losses and such. A normal start that moves into the energy band where the engine can efficiently generate the energy directly shouldn't be any worse for mileage than a painfully slow start to try to keep the engine off. Indeed, it may be better. Here is my logic (quoted from an earlier thread about the battery usage):

LexKid, It seems probable that the batteries are big enough to do what they need to do and making them bigger wouldn't improve mileage. All the power is made by the engine. The most efficient use of the power is when the engine can run in its most efficient band and deliver the power directly to the wheels.

You always lose energy when you move power around - that is why you can't have a perpetual motion machine. In the case of the hybrid system, you lose energy due to resistance of wires and any inefficiency in the motor generator for instance.

Then why do the batteries help mileage? Here are some ways:

They provide a place to store regenerated energy from the braking - in a non-hybrid, the energy of your motion all is turned into heat from the friction of the brakes and is lost to you. In the hybrid, much of it gets turned into electric energy and stored in the batteries.

They allow the engine to operate in its efficient range - The gas engine never has to operate at slow RPM to start the car moving or to coast the car or at very high RPM for passing and other high speed acceleration. Depending on battery charge level, it is either off or it is on at a higher speed with the extra energy being used to charge the battery. Since the operating range of the engine is narrower, the designers can even make changes to optimize performance in this range over the performance of the standard engine that has to support a wider operating range efficiently.

Additional observations: once you have drawn a certain amount of energy from the battery so that its level has dropped below the charge point, the engine will turn on no matter how slowly you try to accelerate.

If anyone has a counter-argument, I'd be interested to hear it.

So far, I find that the main driving habit I can alter to improve mileage is to brake gently. By braking gently, I mean a soft enough foot that the power meter doesn't peg to the bottom of its range so that the braking is primarily regenerative. I find that how soft this is depends on speed. A light touch at high speed gets a lot of regeneration. As the car slows, the brake pedal pressure for the same regeneration increases.

Obviously, there are times when one must brake hard so don't take this to extremes. The most energy wasting stop is one that transfers energy into deforming the front of the car. :o But when you see that red light approaching, it pays to start slowing down sooner rather than later with the hybrid.

I'm seeing poorer mileage on short trips, but then going 5 miles at 23 to 24 mpg uses less gas than going 20 miles at 27 mpg so if all ones driving is in short trips, other than grouping errands together there isn't much one can do.