Un-intended Acceleration Feeling At Highway Speed

[hthybrid1]

Hi All,

I have my rx400h for 1 month now. At freeway speed(50 to 80). The electric motor kick in anytime made me feel like un-intended acceleration at that moment and nervous when drive in traffic. I have to keep the distant between car longer. Do you have the same as my feeling? Any suggestion?

Thanks in advance.

Huey T.

[RX400h]

It certainly does take getting used-to and I do find myself releasing the gas pedal more often I would in a non-hybrid vehicle. Then again, the way my Mazda's auto tranny is set up from the factory, acceleration is very brisk at normal pedal travel from a standstill than it is under similar conditions in most other auto tranny vehicles. Each vehicle has its own idiosyncrises that require slight driving style adjustments.

[hthybrid1]

Hi All,

I have my rx400h for 1 month now. At freeway speed(50 to 80). The electric motor kick in anytime made me feel like un-intended acceleration at that moment and nervous when drive in traffic. I have to keep the distant between car longer. Do you have the same as my feeling? Any suggestion?

Thanks in advance.

Huey T.

←

Finally I figured out the cause of all bad feeling about driving RX400h in the first 3 weeks such as un-intended acceleration; too much "wind effect" althuogh there was not much wind; "Sea sick" on smooth freeway.... The tires pressure! They pump up to 45PSI on my new rx400h!

After reduced to 32 PSI. Everything OK. Average MPG drop from 25.6 to 25.2. I realize other owner post about high tires pressure too.

[RX400h]

Wow! That's even higher than the pressure in my RX400! It was two months by the time I checked, so it is possible that it was up in the 40s from the dealership. I think you'll notice a much smoother ride now that the pressure is back to normal.

[speedyg]

Hi All,

I have my rx400h for 1 month now. At freeway speed(50 to 80). The electric motor kick in anytime made me feel like un-intended acceleration at that moment and nervous when drive in traffic. I have to keep the distant between car longer. Do you have the same as my feeling? Any suggestion?

Thanks in advance.

Huey T.

←

I believe I have felt something like what you describe. I am cruising on the freeway and am not moving the accelerator pedal at all. If I look at the [tire/engine/battery/arrows] indicator in the dash I can see that most of the time it is using the gas engine to drive the wheels but occasionally the electric motor kicks in, at which time I feel some acceleration/deceleration. I'm not sure why the electic motor kicks in to assist, maybe to compensate for gusts of headwind?

The acceleration/deceleration is very mild though, feels more like the car gets hit with a sudden headwind. I have noticed this behavior maybe 4 or 5 times, not sure what conditions trigger it. Maybe it is actually some headwind :)

[katzjamr]

Thanks to your posts i took a tire guage with me when i picked up my 400h. Sure enough all tires were at 40. I asked the otherwise helpful salesperson why tire pressure wasnt a part of dealer prep. He said he would look into it. I think pretty much dealer prep must be taking off the plastic and washing the vehicle. I also checked a flint mica 400h next to mine that sold and ready for delivery, all tires were over 40.

[dobby]

What a timely subject.

I noticed my 400h doing the same thing on the freeway when I took it out for the first few times this past week. The movements correlated with the electric power boost on my dash monitor. While I'm used to "wind effect" movements, having driven an Integra as my last car, I thought it was odd that the 400h would be so much more noticeable on a day with even less wind. On a hunch, I also checked the cold tire pressures...38. Now that I'm back down to 30, the movement from the electric power assist is very subtle.

[speedyg]

What a timely subject.

I noticed my 400h doing the same thing on the freeway when I took it out for the first few times this past week.  The movements correlated with the electric power boost on my dash monitor.  While I'm used to "wind effect" movements, having driven an Integra as my last car, I thought it was odd that the 400h would be so much more noticeable on a day with even less wind.  On a hunch, I also checked the cold tire pressures...38.  Now that I'm back down to 30, the movement from the electric power assist is very subtle.

←

Wierd! I'll have to try adjusting my tire pressure.

Anyone know how the accel/decel is tied to tire pressure? I don't see the connection there.

[hthybrid1]

What a timely subject.

I noticed my 400h doing the same thing on the freeway when I took it out for the first few times this past week.  The movements correlated with the electric power boost on my dash monitor.  While I'm used to "wind effect" movements, having driven an Integra as my last car, I thought it was odd that the 400h would be so much more noticeable on a day with even less wind.  On a hunch, I also checked the cold tire pressures...38.  Now that I'm back down to 30, the movement from the electric power assist is very subtle.

←

I drove my rx400h to Catch Creek casino last weekend. On the country road(small, undivided road) at low cruising speed(40-45 mph?? I forgot); the RX400h perform just like pure gasoline engine although electric motor is still kick in for better milages. It make me wonder if the RX400h need to fine tune the software to control electric power at higher speed?? May be we can get a software upgrade in the future?. I hope Lexus manufacture are listening us.