Rx450H Gas Mileage

[lemon]

It's great reading all this stuff (I thought I'd seen all the old reviews for the 400h - that's a new one jaswood).

Me, personally - I don't care if I meet the numbers posted by the EPA / Transport Canada. All I know is my fuel economy is much better than that of a friend with a 2008 RX350 and better than that of my wife's 2010 Equinox. I may not be seeing the magical numbers posted by the EPA (and very few people / vehicles ever do as those tests are under controlled conditions - driving in the real world introduces many more variables like wind, passengers, cargo, road conditions, traffic etc.) but I'm quite happy with 8.1 l/100km in the summer and 9.5 in the winter (per the onboard trip computer, which may not be as accurate as manual calculation).

Hmm...looks like those numbers I'm seeing exceed the EPA estimates...lol.

[smitty49]

Finally got Lexus to do some testing on gas mileage but they refuse to test it under the circumstances that the car if failing under. Lexus did a short highway run and daid it meets their standards. The problem I have is on long hiighway runs of several hours hours where the mileage gets progressive worse the longer you drive. I was also told by the local dealer that getting to 22 to 25 miles on a long highway run is normal. Seems like Lexus is not interested in solving the problem. I have seen where others are experiencing similiar problems. Not sure what happened to Lexus customer service

[jaswood]

Finally got Lexus to do some testing on gas mileage but they refuse to test it under the circumstances that the car if failing under. Lexus did a short highway run and daid it meets their standards. The problem I have is on long hiighway runs of several hours hours where

the mileage gets progressive worse the longer you drive.

SOP.

I was also told by the local dealer that getting to 22 to 25 miles on a long highway run is normal. Seems like Lexus is not interested in solving the problem. I have seen where others are experiencing similiar problems. Not sure what happened to Lexus customer service

If you start out having accrued a good deal of city stop and go mileage, the condition wherein the HSD system SHINES, stellar FE in comparison to a non-hybrid, then that is EXACTLY what you should expect. Now drive on the highway long enough, enough distance, and the MPG reading will decline very close to the highway average, prossibly even lower than an equivalent non-hybrid.

On the highway the HSD system will have very little opportunity for recovering FREE energy via regenerative braking. The ICE will, therefore, be the primary source for restoring the SOC of the HV battery whenever that becomes a requirement.

So, on the highway you have not only mostly lost the ability to recover FREE energy, you now must make use of a fairly lossy path for/to recharging the HV battery.

[The G Man]

Finally got Lexus to do some testing on gas mileage but they refuse to test it under the circumstances that the car if failing under. Lexus did a short highway run and daid it meets their standards. The problem I have is on long hiighway runs of several hours hours where the mileage gets progressive worse the longer you drive. I was also told by the local dealer that getting to 22 to 25 miles on a long highway run is normal. Seems like Lexus is not interested in solving the problem. I have seen where others are experiencing similiar problems. Not sure what happened to Lexus customer service

Do you really expect Lexus to test drive your car for 2 to 3 hours? You should calculate mileage manually anyways, the MPG computer on the dash is use for reference only, it’s not very accurate.

[maseace]

The problem I have is on long hiighway runs of several hours hours where the mileage gets progressive worse the longer you drive. I was also told by the local dealer that getting to 22 to 25 miles on a long highway run is normal.

Try resetting the fuel economy meter when you are up to freeway speeds, then see how much it changes on that long drive. This way it won't be influenced by any city driving before you are up to freeway speeds.

[John219]

My RX450H has typically gotten 28 - 32 mpg for highway trips (~150 miles). Overall average for past 25k miles (per the computer is just under 28. However, recently it's been closer to 26. One tire was slightly low so I've pumped it up. Will see if that brings me back to the typical 28 MPG range. Sounds like others don't routinely get this?

[alex1372]

I just came from 1300 miles trip from Chicago to Niagara Falls - average on the trip was 23-25MPG driving 70-85MPH; drving for a whole week to and from work 23 miles one way with average speed of 40-60MPH mostly expressway fuel economy is 28.5MPG - typical hybrid fuel economy and i'm very happy about these numbers comparing to my old 05 Acura RL - i was getting about 25.5MPG on long interstate trips, about 22.5MPG to and from work, and i really tried to avoid the city - 16-18MPG

I noticed that any speed above 60MPH reduces MPG significantly