Rx400h -- Use Of Electric Motors

[jj_fender]

I just bought my RX400h three weeks ago and have driven about 300 miles, mostly around town with some freeway driving. I am monitoring the mileage and have not yet come up with any concrete numbers. I am not sure I believe what the instrument panel is telling me..."average 21.4 MPG." Although, this seems to be going up all the time.

One thing that is a little disappointing, I expected the car to go a little further on the electric motors before the gas engine kicks in. For example, after driving awhile on the freeway at approximately 65 MPH and charging the batteries, I approached a traffic jam on a fairly level stretch of freeway. The engine shuts off when I stop but i barely go 20 feet before the gas kicks back in. I have tried gently touching the gas pedal to see if I can get it to go further but it only seems to go 10 to 20 feet before the gas engine kicks in again. This is a little frustrating when you are in stop-and-go traffic because the gas engine is going off and on all the way down the freeway. Is there any way to adjust this??

[RX400hGirl]

I just bought my RX400h three weeks ago and have driven about 300 miles, mostly around town with some freeway driving.  I am monitoring the mileage and have not yet come up with any concrete numbers.  I am not sure I believe what the instrument panel is telling me..."average 21.4 MPG."  Although, this seems to be going up all the time. 

One thing that is a little disappointing, I expected the car to go a little further on the electric motors before the gas engine kicks in.  For example, after driving awhile on the freeway at approximately 65 MPH and charging the batteries, I approached a traffic jam on a fairly level stretch of freeway.  The engine shuts off when I stop but i barely go 20 feet before the gas kicks back in.  I have tried gently touching the gas pedal to see if I can get it to go further but it only seems to go 10 to 20 feet before the gas engine kicks in again.  This is a little frustrating when you are in stop-and-go traffic because the gas engine is going off and on all the way down the freeway.  Is there any way to adjust this??

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Are you running Air Conditioner by any chance? I'm wondering if the engine is kicking in to power aux activity. When I'm in a traffic jam I do see the engine kick in a times, but not as often as you describe.

[jj_fender]

I have tried running with the air conditioner off and it does not seem to make any difference. I was hoping that the gas engine would not kick until you are going, say, 20 MPH or so.

One time, however, when I was showing off the new car, I drove down the block and back all on electric. I think it is dependant on the charge of the battery system and may improve over time.

[cosimoto]

Keep driving it. Hybrids have a long break in period. You will start to see better MPG (and consequently more electric motor use) over time.

I have tried running with the air conditioner off and it does not seem to make any difference.  I was hoping that the gas engine would not kick until you are going, say, 20 MPH or so. 

One time, however, when I was showing off the new car, I drove down the block and back all on electric.  I think it is dependant on the charge of the battery system and may improve over time.

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[patt]

I agree there is a break-in period. There is with all cars - but hybrid drivers seem to watch mileage closely partly because Toyota/Lexus gives us monitoring to do so. There was a noticeable improvement on our second tank on which we averaged 26 mpg. The first 50 miles on the third tank, we averaged 27 then the weekend hit with too many short trips and dropped us back to 26.5.

Also, if you didn't reset the mileage monitor after you got it from the dealer, it starts out (at least ours did) with a pretty poor number from whatever the tech did in preping and checking the car.

From what I've observed so far, the motors don't have to run as much as many people here seem to think they should to get good mpg numbers - especially the car running totally on the electric motors. On longer drives on suburban streets, I've seen 30+ mpg and on mixed freeway and surface street, I've seen 27 with the air conditioner running. During that, the engine was usually off during coasting down, breaking, idling (after the warm up at least), the very start of moving from a stop and sometimes while cruising at steady speed. The motors were also assisting the engine at various times for accelleration or maintaining speed.

[marmadmax]

Don't give up yet. I just passed 1000 miles and gassed up for the 3rd time. Second tank averaged just under 26 mpg - both computer and manual calc. I reset the computer after the that fillup. This last tank was even better. The trip computer calculated 27.9 mpg. My calculation of fuel consumed showed an even better 28.75. I would estimate 70/30 highway/city driving.

My electrics shut off quickly too when starting from a stop. However, I have noticed that the worst mileage is the first outing of the day or whenever the engine is cold or the batteries are not charged - not sure which is really causing the issue. This past week, I have been driving a relatively short 5 miles one way. The car sits all day, and then I make the return 5 mile trip in the evening. I am doing well to average 24 mpg in all slow, city driving. About the time I am ending my trip, I start to see the electrics begin to perform a little longer. Others have posted this same issue. There is a "warm-up" period during which the mileage suffers. If the 400h is going to be used consistently for very short hauls, there may be difficulty in achieving predicted mpg levels. Otherwise, be patient, the mpg will come.

Enjoy.

[ReXus]

Speed will kill your mileage. Since getting my RX400h a few weeks ago, I've been alternating between driving like I was trying to set a new high-mileage record, and driving like a reasonable, but calm driver.

Today, I got on the Thruway and took the h up to 95 mph for a short spell and did most of my driving at 80 (with the flow of traffic). Mileage at that speed: 22mpg, easily my worst yet.

But now I've experienced both the Jeckyl and the Hyde of this car. Frugal miser vs Speed demon. Both personalities are lots of fun in their own delightful way.