Rx400h Not Up To Specs

[RX400h]

OK...here's the deal on my White/Beige RX400H.  I just put a little over 500 miles on the car and filled the tank for the second time.  I had not reset the average MPG until today at the gas pump.  Up until that point the Average MPG read 22.7.

But this included whatever the dealer did during test drives.  Between the last fill-up and this one, I traveled 302.9 miles which took 13.0 Gallons.  That is exactly 23.3 MPG. 

After this last fill-up, I reset the Average MPG using the NAV System.  I decided to baby it a bit to see if I could get the mileage up.  The first part of my trip around town actually recorded 33.4 MPG Average but by the time I had run my errands and retured home the Average MPG was back down to around 24 MPG. 

I am really trying to get good mileage.  I do not gun the engine or run the air conditioner.  But I have a hard time believing people who say they are getting over 27 MPG.  This car has a lot of "breaking in" to do if I am going to reach these specs.     :(

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We now have over 1000 miles on our 400h and are consistantly averaging 25 MPG with plenty of city and highway use. A Volkswagen new Beetle averages 25 MPG, so anyone who complains about that kind of mileage from a 4500-lb all wheel drive SUV that rockets to 60 MPH in 6.9 seconds should re-investigate real-world gas mileage! After one week of back and forth to work and Saturday and Sunday driving, we spent $15.00 to fill it up. By contrast, out 86 Honda Accord 4-cylinder would travel the same number of miles and cost $11.00 to fill up at 95 cents per gallon. Our Nissan Quest was costing us $25.00 to $28.00 to fill up at current prices.

Needless to say, we are VERY happy so far!

BTW, my coworker's RX330 is averaging 16 MPG in mixed driving....ouch!

[indiasfinest]

man my GX gets horrible MPG...like around 14-15.....i feel ashamed...i pay freakin $40 bucks at the pump and it runs out in a week....thats annoying. o well, the salesmen once told me...if you cant afford the car dont buy it....i went to a different dealer.....that reminds me about something that happened along time ago (srry its off topic)

in 89' i walked into a lexus dealership looking for a car for a couple k. n e wayz when i talked to a salesmen...and told him my price range....he said in the exact same words.."sir, i dont think you can afford a lexus" and ten years later...i went to the same dealer ship and bought a car for 60k. man..it brings back some memories.....ok srry for the off topicness.

[RX400h]

The sad thing is that even though many people can qualify for a $60,000 vehicle, it does not mean that they can readily afford it. You wouldn't believe how many Corvette owners out there live in an apartment or condo with NO garage. The salesperson told them they could afford it..........

[the-headless_horseman]

Okay, everyone, here's an update...

I now have about 1700 miles on my RX400h. I can honestly say that highway mileage will range between 26 and 28 depending on speed...figure about 28 mpg at 60 mph...more like 26 mpg at 75.

In regards to normal, everyday use...I'm around 24 mpg...still disappointed with this and don't expect too much more. I do have to admit that my area is probably the worst area to drive for fuel efficiency...many roads here are 45 mph limits with lots of hills and lights on the hills...sometimes you have to accelerate to get over the hill...this is an efficiency nightmare!

As far as performance, the car is great...very comfortable...I don' t have the ML audio (although I wanted it) but I can safely say the stereo is 'good enough.' Listening to Flamenco (by Jesse Cook) is rather clear...tweak the mid range a bit to help!

The voice activation is incredible if you can get a printout of all the commands...anyone have one? There must be a few hundred commands....I only know a few...HELP with this one please!

Everything else good to go...for all you newbies, get a cargo mat...I leave mine rubber side up to prevent sliding when taking turns at a speed faster than 10 mph...

As far as eletric motor running at certain speeds, I have found that the more warmed up the car, the more efficient both the gas and electric motor(s)...still hard to get car to run only on electric if you want to accelerate with any respectability...

Anyway...still probably another 2000 miles for total engine breakin...I'm figuring I'll end up with 25 mpg 'normal' use, as described above, and about 27 on the highway...if ever in bumper to bumper traffic, you can safely assume the 31 mpg with no problem!

Headless

[wwest]

Hmmm...

28MPG hwy...

24MPG....everyday use.

You do recognize that to be backward from what Lexus has promised?

[SW03ES]

I dont get it wwest, it infuriates you that real world mileage seems to be 5-6 MPG off on the RX400h, but it doesnt bother you the Average Prius only gets as much as 20MPG less than what Toyota promised?

The BEST mileage I've ever seen on my Prius is 48MPG. What about 60? My mileage in the Prius also tends to be better on the highway for whatever reason, also backwards. Why doesnt that make you as mad?

[RX400h]

It looks like the highway milage we (forum members) are seeing is right on the money and city is basically unproven, as most of us do not drive exclusively in the city. So, based upon what I've seen and experienced, actual highway mileage matches EPA and for the majority of 400h owners, 24-27 MPG average of our types of driving is extremely close to the EPA numbers. Well done, Lexus!

[the-headless_horseman]

Hmmm...

28MPG hwy...

24MPG....everyday use.

You do recognize that to be backward from what Lexus has promised?

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No, not backward. 24 mpg refers to 45 mph roads with frequent stops and needing to get back up to speed quickly so the person behind you doesn't ram into you! This leads to the worst mileage, no matter what car you drive...by the time you coast, you have to stop again...

On the highway, at least you get to coast, especially with cruise on (definitely recommend cruise when on the highway)...this is where your mileage numbers go up...or, of course, when you're in bumper to bumper traffic and only the electric motor is working...

Headless

[patt]

Hmmm...

28MPG hwy...

24MPG....everyday use.

You do recognize that to be backward from what Lexus has promised?

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What I have noticed is that highway mileage (for a freely moving highway) is more stable than city mileage. Not surprising since it covers a narrower range of conditions. On the highway, I almost always get about 27 mpg at 65 mph unless the AC is running really heavily which can drop it by something a bit over 1 mpg.

Warmed up city mileage with moderate driving - normal acceleration, gentle braking I see 28 to 33 mpg. The problem is that at slow speeds this can vary. For instance, stop and go with a lot of AC on a hot day the engine is having to work to generate for the AC but the car isn't moving much. Short trips, traffic that behaves too abruptly for gentle braking and other non-optimum things can vary mileage a lot more than cruising along on the freeway. City milage is much more sensitive to driver behavior in my experience with this car so far. That's when I'll see 25 mpg. Last tank (the third one) we averaged about 26 mpg. On the first 100 miles of this tank I was running better than 27.5. Then I let a visiting family member drive and he pulled the number down as he checked out the performance and wasn't as gentle with the brake.

[CKK]

I've had my 400h for awhile. I am a former 2001 RX300 owner. Here is what I've noticed:

On long short trips (does that make sense?) i.e. local trips longer than around the corner, the mpg is about 31. On the highway, the mileage drops to about 26. You do need to alter your driving habits a bit (more coasting, less sudden acceleration) in order to optimize the mileage. If you watch the Energy schematic while driving, you can quickly get the technique down. I don't find this bothersome.

I am REALLY happy with this car. But perhaps it's because I didn't have expectations of it being a an "mpg powerhouse" like the Prius et al. I was second on the wait list at my dealer a year and a half ago, and my sales rep kept me very well informed of status reports on the vehicle. He called about six months ago to have a discussion with me about the mileage issue - to make sure that I understood that the 400h was geared to performance as well as good mileage, thus the mpg was not going to be like the other hybrids out there.

It seems to me that Lexus is trying to compromise among several factors: large vehicle, great performance and power, and luxury. At this point, I just don't know that it's possible to have our cake and eat it too.

That said, I'm getting great mileage compared to my RX300 (averaged about 17), and awesome performance. I feel great about not filling the space around me with pollutants while I'm stopped at a light or driving into my garage. Frankly, I think that it's the perfect vehicle for someone who drives on the highway daily (because of the great performance), and then spend loads of time after work running kids around to local stops - in other words - most parents.

[the-headless_horseman]

I've had my 400h for awhile. I am a former 2001 RX300 owner. Here is what I've noticed:

On long short trips (does that make sense?) i.e. local trips longer than around the corner, the mpg is about 31.  On the highway, the mileage drops to about 26. You do need to alter your driving habits a bit (more coasting, less sudden acceleration) in order to optimize the mileage. If you watch the Energy schematic while driving, you can quickly get the technique down. I don't find this bothersome.

I am REALLY happy with this car. But perhaps it's because I didn't have expectations of it being a an "mpg powerhouse" like the Prius et al. I was second on the wait list at my dealer a year and a half ago, and my sales rep kept me very well informed of status reports on the vehicle. He called about six months ago to have a discussion with me about the mileage issue - to make sure that I understood that the 400h was geared to performance as well as good mileage, thus the mpg was not going to be like the other hybrids out there.

It seems to me that Lexus is trying to compromise among several factors: large vehicle, great performance and power, and luxury. At this point, I just don't know that it's possible to have our cake and eat it too.  

That said, I'm getting great mileage compared to my RX300 (averaged about 17), and awesome performance. I feel great about not filling the space around me with pollutants while I'm stopped at a light or driving into my garage. Frankly, I think that it's the perfect vehicle for someone who drives on the highway daily (because of the great performance), and then spend loads of time after work running kids around to local stops - in other words - most parents.

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The same trip to work I was originally getting 22.9 mpg with I am now getting close to 25 mpg...reason? Change in driving style to allow for more coasting (when available) and I guess some engine breakin...

I also figured out that the less battery you use when the car is off, the less the ICE wil run when you first start up...it seems that there is an automatic battery charging session when you first turn on the car...and this will NOT show up on your dash display of the engine/battery energy control...haven't checked the navi screen on this though...

Headless

[JasonATL]

I've had my 400h for a week now, with nearly 250 miles on it. The first 100 miles averaged about 22 MPG. The last 150 or so have averaged 27 MPG. There is about 30 miles of open hwy (60+ MPH) in that.

My limited experienced is that I've had to change the way I drive fairly dramatically (my last car was an RX 300). The biggest change is the coasting. The other thing that an earlier post mentioned was how this car appears to have a cruise-control that does far better than the car allows the driver to do with respect to mixing ICE and electric. I guess this is a performance issue -- if you're using the "gas" pedal, then the car is prepared to give you what you want at any time. On cruise, it seems to mix in the electric motors much more, even on cruise at 35 to 45 MPH. I didn't used to set the cruise control on my 10 mile hwy drives, but I would only set it on long trips. Now I will try to set it whenever possible and safe to do so. It seems to kick the MPG up by 5 or so. Again, these are just my observations after a couple of hundred miles.

So far, I love this car. Like a previous poster, I love sitting in traffic or going through a parking lot/garage with zero emissions.

By the way, someone might have mentioned this before, but more caution is definitely needed in parking lots: pedestrians can't hear us! The audible clues aren't the same with the 400h when the ICE is off. I think Lexus would do well to put this warning in the materials somewhere (perhaps they do and I missed it).

[dylan400h]

The other thing that an earlier post mentioned was how this car appears to have a cruise-control that does far better than the car allows the driver to do with respect to mixing ICE and electric.

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Yes, I agree completely. The cars seems to use the engine more smoothly under cruise.

I believe it has other programming to improve efficiency as well. I carefully observed what I think is an interesting algorithm at work. With the cruise on, the car holds speed pretty accurately, but when you crest a hill and the engine turns off to coast, the cruise allows the speed to coast down 5mph before restarting the engine and accelerating back to the set speed. Furthermore, while it is coasting down, it runs the electric motor only (warp stealth) to try to maintain speed as long as possible before restarting the engine. To observe this, set the cruise high, 75 or so, and set the speedometer display to the energy use graphicto see speed and energy together at a glance. The system is smart. I had assumed that I could do better than any cruise system by anticipating hills and blending the speed, but this is not just a dumb setpoint only cruise control.

I have taken to driving with cruise as much as possible, using the stalk to accelerate and coast within reason in light traffic.

I really think this car should have a sport button that give you the engine always available for quick acceleration, and an economy button with much less aggressive software. One of the major benefits of all these computers is that it should be able to be two different cars at whim of the driver.

[dylan400h]

I also figured out that the less battery you use when the car is off, the less the ICE wil run when you first start up...it seems that there is an automatic battery charging session when you first turn on the car...and this will NOT show up on your dash display of the engine/battery energy control...haven't checked the navi screen on this though...

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The engine runs for an auto charging session if the battery gets down to 2 bars (magenta). That is lower than the Prius is allowed to go, so Toyota is getting more aggressive in battery utilization.

When you start up there is an engine warm up to get the engine, but especially the catalytic converter heated up. I don't think the 400h has a heat battery coolant cannister like the Prius. In this case you may not see the motor on the display since it may or may not be charging the batteries. I have seen the motor running but not on the display. They run the engine at slightly elevated RPM with a very retarded spark timing to get the exhaust as hot as possible with no load to heat up the catalyst even if the battery does not need charging to its 4 or 5 bar target level.

[wwest]

It appears that most RX400h owners posting information are reporting better highway MPG than city. Example, 28 hwy, 24 average.

Many owners are seemingly struggling to find the "proper" way to drive the RX400h in order to get better fuel economy....

Puzzling, VERY!

The Prius DEFINITELY has better city fuel economy than highway.

I have NEVER heard anyone say that special driving techniques are needed for the Prius.

Yet both the Prius and the RX400h use the very same Toyota hybrid design concept.

What went wrong?

[JasonATL]

It appears that most RX400h owners posting information are reporting better highway MPG than city. Example, 28 hwy, 24 average.

Many owners are seemingly struggling to find the "proper" way to drive the RX400h in order to get better fuel economy....

Puzzling, VERY!

The Prius DEFINITELY has better city fuel economy.

I have NEVER heard anyone say that special driving techniques are needed for the Prius.

Yet both the Prius and the RX400h use the very same Toyota hybrid design concept.

What went wrong?

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I, for one, do not claim that special driving techniques are needed any more than driving a RX 330 is different from driving an ES 300, a Mercedes SUV, a Honda Civic, or a Toyota Tundra. It is different, just as any car is different. The hybrid technology accounts for some (if not most) of the difference to me -- given that my reference was my 1999 RX 300. The biggest difference is the lack of engine braking (if this is the right term). I don't have to let off the gas pedal going on flat or downhill sections - but I can -- something I cannot do with any other car that I have driven. This saves gas. Again, something that I cannot do with any other car.

I think that Lexus has tried to be careful (I know my dealer was careful) to pitch the hybrid tech on the 400h as performance, without an extra hit to fuel efficiency. It seems to work. The 400h is very responsive in my opinion and a pleasure to drive.

The EPA numbers are EPA numbers. I've never had a car that met them. I use them as comparative numbers, not as something I expect to achieve on any car.

So, in my opinion, nothing went wrong. I'm realizing 30% to 35% better mileage (granted, I only have 250 miles -- and probably not miles that would favor better mileage) compared to my RX 300.

If I had bought an RX 330 a couple of weeks ago rather than an RX 400h, I'd be wondering why. Sure it is a premium at entry, but it is very likely to fetch a premium in trade or resale. So, the premium is very possibly a wash.

[wwest]

I never expect any vehicle to match the EPA numbers, but everything I have read about the Toyota hybrid system indicates that city MPG should be better than highway, yet.....

[JasonATL]

I never expect any vehicle to match the EPA numbers, but everything I have read about the Toyota hybrid system indicates that city MPG should be better than highway, yet.....

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Agreed, but I think it might be a bit early to tell. Some here have had 1,000 miles, while many of us have little evidence to go on. In short, a comprehensive or conclusive "experiment" hasn't been done.

Unfortunately, I am unlikely to ever be able to tell, since my "city" driving is a mix of hwy and short trips on very hilly roads (which I doubt will favor the hybrid system in the city over hwy driving). All I can look at is my mix vs. the same mix I see on my RX 300. In this (fair) comparison, I see 30% to 35% better mileage in my limited experience.

[wwest]

Just how HOT must the catalist in the catalytic converter be in order to have the RX400h remain in the ultra low emissions class? Does it have to run the ICE fairly often in city use to keep the catalist "lit" off??

[dylan400h]

Everyone who has been stuck in traffic for any length of time, me included, has achieved low 30's MPG for sustained periods. Remember what the EPA test cycle is, a time and speed profile that any car, no matter how underpowered, can easily follow with very gentle starts and stops.

I think another factor in the 400h city MPG is that the 400h has about the same size battery as the Prius, which puts it at a disadvantage in stored energy utilization.

In my experience both the Prius and the 400h benefit from special, high MPG driving techniques. I get in the high 50's in a Prius when I drive very carefully, versus high 40's normal.

[dreamchaserflorida]

It appears that most RX400h owners posting information are reporting better highway MPG than city. Example, 28 hwy, 24 average.

Many owners are seemingly struggling to find the "proper" way to drive the RX400h in order to get better fuel economy....

Puzzling, VERY!

The Prius DEFINITELY has better city fuel economy.

I have NEVER heard anyone say that special driving techniques are needed for the Prius.

Yet both the Prius and the RX400h use the very same Toyota hybrid design concept.

What went wrong?

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Actually, Prius Forums often report on special driving styles which raise the mpg.

Owners describe their driving technique efforts for better fuel consumption.

They are attempting to use the battery more (sometimes call "stealth mode" at certain speeds or in parked status) and the gas engine less so reports are of anticipating a stop, coasting, lower speeds, cruise control use, avoidance of "stomping on the gas", etc. etc. The same techniques should apply to the 400h although the 400h is less fuel-efficient due to size, power and design.

Yes, the Prius has better city fuel economy than the Lexus... it is a different car than the 400h. This is not puzzling.

However, it is puzzling about the few Lexus owners' reports of higher highway mpg as compared to city driving. This seems against the technological design.

[dylan400h]

Just how HOT must the catalist in the catalytic converter be in order to have the RX400h remain in the ultra low emissions class? Does it have to run the ICE fairly often in city use to keep the catalist "lit" off??

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As far as I know, there is no catalyst temperature sensor, just the upstream and downstream O2 sensors. Once a cat has lit off at about 250 degC, its temp rises rapidly from the fuel reactions to its operating temp. When the engine stops, so does the airflow, so the ceramic catalyst in its ceramic matt packaging, stays hot. I dont think they do anything other than initial cat warmup for a cold start.

It does beg the question what happens when the engine spins with no fuel, either in B mode, or warp stealth with electric only above 43mph, does cold air cool the cat?

Warm catalysts are all about good performance on the EPA test. Emissions control systems got so effective that all of the emissions in the test came from the cold start period before the catalyst lit off. 0% effectiveness for 30 seconds or a minute overdhadows 99% versus 99.5% effectiveness for the rest of the test. So especially for SULEV, startup emissions are critical.

[wwest]

"engine spins with no fuel...."

Nor any oxygen, air, since the throttle is closed.

[dylan400h]

"engine spins with no fuel...."

Nor any oxygen, air, since the throttle is closed.

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Less air, but a throttle plate is not an airtight valve. When it is "closed" the air necessary for idle still flows.

[wwest]

Actually the throttle plate is "airtight". Most modern day cars have a variable idle air bypass path around the throttle plate that can be restricted by the ECU to attain the correct idle RPM under differing idle loads, A/C, power stearing, etc.