High speed pulsing/surging/dragging...anyone else feel it?

That sure sounds like a wheel issue to me. If you speed up a little bit and it goes away, I'd definitely have the balance and/or alignment checked. Of course, the tires themselves may reveal the problem if there is enough wear no to indicate an uneven amount of tread.

 

You mention this is when the ICE and electric motors are both engaged. Could be your speed and the car's control strategy are in just the right (or wrong) place to have you switching modes between motor assist being on and off. Thus, the electric motor kicks in for a few seconds, you speed up without changing the pedal command, and the electric motor stops again. You slow down and the motor kicks in again.

Is your issue repeatable at a range of speeds? (say +/- 5 mph) Try getting on a stretch of level road and getting up to the speed where this happens. Set the CC and watch the MFD (energy screen) to see what's happening (remember, there's a slight delay). Then use the CC to increase and decrease you cruising speed while observing the MFD.

 

That "surging" is really the only thing that bugs my wife when she drives it. I *think* it only seems to happen once the car is done recharging the battery, and then is trying to assist you to maintain speed by mixing in little "spurts" of electric power. Thats my theory. :huh:

 

Is the A/C on? If so, it can manifest itself as a slight surging as the compressor cycles on and off. Does it occur with the cruise control on?

 

I feel the surging in my 2006. It's the only odd characteristic about driving my Prius. As you say, it isn't noticable at low speeds, but only when highway driving without using the CC. It feels like you can't get the car to drive at a consistent speed without modulating the pedal. Oddly enough, I think my Prius gets better milage when I drive it without the CC and let it surge a little.

 

<div class='quotetop'>QUOTE(upland_bill @ May 3 2006, 09:10 AM) [snapback]249026[/snapback]</div>

We've had ours a week and noticed exactly the same thing at 60 mph+. Like there is something pulling at the car or like being buffeted around behind an 18 wheeler. Seeing this regularly discussed on Priuschat, I am writing this off to one of the quirks of the car, not a defect in mine. I get the sense it may relate to the aerodynamics of the car as well as perhaps to the relationship between the long wheelbase and the narrow tracking width. I have already ordered the stiffening brace in the hopes it will contribute to some improvement.

 

I think McShemp is on the money. Your at the center of going gas and electric. I get it on my 2006. I drive about 114 miles a day 90% hwy. I do a lot of lifting off the gas and applying the gas pedal.