jj_fender

I completely agree with these figures. I have had my RX400h since April and have had almost exactly the same results. Makes you wonder about those people who claim to get 30 MPG. I don't believe them.

The truth. Driving habits: Conservative Air Conditioning: Rarely Long Trips: Few Coasting When Possible: Yes Slow starts: Yes Date Miles Gallons MPG 6/17/05 298.7 12.5 23.896 7/1/05 337.5 14.133 23.8802802 7/15/05 277.2 11.8 23.49152542 7/31/05 277.1 11.93 23.22715842 8/15/05 261.1 11.247 23.21507958 9/2/05 284.5 12.623 22.53822388 The average MPG on the screen says 24.5 MPG which, as you can see, is high. I don't know about these other people. Either my RX400h is a lemon or someone is exagerating about their MPG. Why? I don't know. Maybe they work for Lexus. Good mileage is important to me. Especially with gas prices soaring. This car has simply not lived up to specs.

Thanks again Patt. I did check out the EPA site and found that it is very informative. One thing that I had not considered is the differences in fuels. Here in California, they add all sorts of things to the fuel which raises the cost and probably lowers mileage. The EPA says that they used real drivers to simulate different driving conditions in the city and highway. If that is the case, they should be pretty close to real driving. However, they only test about 15% of the cars themselves. The other numbers come from the factory...hmmm. The test drivers at Lexus supposedly got 30 MPG driving in "city" conditions. It would be interesting to hear from the Lexus people about how they accomplished such an incredible feat. Again, as hard as I try, I am only getting 24.7 combined city and highway...about 20% lower than those amazing factory drivers.

There is a big difference between averaging 24.6 MPG as you are and never getting more than 24 MPG as Judy reports. Averaging 24.6 may be consistant with the EPA MPG numbers depending on how different your driving is from the EPA city and highway numbers. I get the EPA numbers when I drive something close to the EPA profiles. Our average over the life of the car so far is just over 25 mpg though that includes using AC . By the way, I have found that painfully slow starts don't seem to be the best thing for mileage. I get as good or better mileage when I go fairly promptly up to speed and then cruise. And why would you spend 50K to drive a car where you can't use the air conditioner? ← Thanks for the reply Pat and the advise about the slow starts. I don't quite understand what you mean by a "big difference between averaging...and never getting...." Isn't the EPA some kind of average. My average just happens to be over more than 1000 miles. Anyone can get EPA MPG numbers or above on a particular trip. For instance, when I first reset my average MPG (actually the only time I have reset it) I went to my mom's house (mostly downhill or flat) and averaged 36 MPG. But that is meaningless. EPA estimates should take into account a variety of driving conditions over a considerable period of time. Not just one or two trips.

I personally do not believe that you are doing anything wrong. I have about 2000 miles on my RX400h and the average is 24.6 MPG. I coast whenever possible and do not use the AC even when it is hot. I practice painfully slow starts whenever there are no cars behind me. It is frustrating...the car just does not even come close to the advertised mileage. I expected more than this.

I agree with you 100% Stevskc. The low MPG is not due to your driving habits. I have almost 2000 miles on my RX400h and believe that I will never be able to average over 26 MPG. I just started working about 5 miles away and my average has been dropping. The highest I ever got was 25.2 with no air conditioning, no passengers, and a 30 mile round trip commute. Now with the shorter commute, I am down to 24.6 MPG. The only time I have reset my average MPG (using the Nav system) was after the first tank full. That is because I believe the dealer tested the vehicle pretty hard and killed the mileage. Before the reset I was averaging 22.5 MPG. People that claim higher mileage must have fairly long commutes. The MPG is simply not what Lexus claimed. I also believed the electric system would work harder. I never see the rear motor come on and the ICE kicks in way too soon. When I saw the avertised 30/27 MPG, I thought the electric would do more work around town. It is a nice concept, but it just doesn't work as advertised.

How in the world does anyone "make sure all trips are at least 8 - 10 miles long ..." Am I supposed to pick a grocery store that is ten miles away just so my average will go up? Does the posted 30/27 MPG only apply to people that live at least 10 miles from the nearest store? That doesn't make sense.

"Short trips in the 400h kill your mileage. Am I wrong in suspecting that is the cause of most complaints?" I think you are on to something there Philly. Someone else mentioned that the oil viscosity is higher at cold temps. Maybe that explains the disasterous mileage on short trips. However, everone has to go to the store, to school, to work, to the tennis club. Lexus should have considered this when they posted the 30/27 MPG. Remember that the 30 MPG was supposed to be around town...i.e., short trips.

Let me know what you get after a couple of more tank fulls. Make sure to not reset your MPG counter on the Nav Screen. It sounds like you have been resetting it which does not give you an accurate average. A longer average should include short trips to the store and such. If you still get such great MPG, let me know why you think my MPG is so much lower. Please ... no posts from Lexus employees. <_<

I have had my RX400h since April and have noticed something very peculiar about the Conservation Monitor on the NAV Display. Like another post, I have spent entirely too much time looking at this thing. Normally when the display shows only green arrows (charging the battery) the MPG says 99.9...but when the car is parked for a few hours this is not the case. Let me explain... I park in a parking structure on the forth floor. When I start the car after work I cruize all down hill through the parking garage...nothing but green arrows pointing toward the battery symbol or the battery running the electric motors. Either way the MPG shows 6.7, 8.2, 12.0, 11.3 ... etc... all the way down the parking garage. When I get to the bottom and cruize a bit, it goes back to the 99.9 display when coasting or using the electrics. How can this be? Has anyone else seen this phenomenon? I would think that it would immediately display 99.9 MPG when not using the ICE.

I am curious Lexbone, do you drive on fairly flat terrain? I noticed that a LX400h owner from Florida seemed to get higher mileage also. I am now right in between 24.9 and 25.0 MPG and it seems to be a real battle to try to keep it over 25. I am wondering if it is because I live on a hill in San Diego with many hills and canyons. One thing I am convinced of; the car definately gets better MPG on the freeway. Once a week I take a 50 mile round trip and can get the average up about .1 The LX400h was supposed to get better mileage around town. The fact that it does not is disapointing. The electric motors were supposed to work a little harder and ease the burden on the ICE.

Patt, sorry it has taken me so long to respond, haven't been on lately. The temperature has not been a factor. I live in San Diego by the beach and I have rarely used the AC. It seems that no matter what I do, I can't push the Average MPG past 25.2. I think that the people that report higher MPG must reset their computer frequently and take the best average. That is really not the way to do it. I believe that once you reset (using the Nav Screen) to remove the factory and dealer testing miles, you should not reset the average MPG. A true average should be over a long period of time, not just one tank. I now have about 1300 miles on the RX400 and have filled the tank three times. ;)

I have now driven a little over 1000 miles on my RX400h with a mixture of city and highway miles. I have really been babying this car, coasting whenever possibe, starting of from red lights like a grandma (sorry grandma). No matter what I do the very best average MPG is 25.2. This is with no passengers and no air conditioning. I find it very hard to believe that other RX400h vehicles are getting vastly different mileage.

I have noticed when cruizing on the freeway in my RX400h, the electric motors kick in at certain times, e.g., when on an easy flat or slight downgrade. This might give better overall mileage than the RX330. I have also noticed that my average MPG goes up the more I travel on the freeway. When I travel around town my average MPG goes down. This is exactly the opposite of what I expected from the hybrid design.

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. :(