S344

I was test driving a 2015 ES300h the other day and noticed during the drive that I could hear a very very faint high-pitched whistling/whining noise which would come and go. I couldn't really tell whether it was more prevalent while on the throttle or while coasting, but it was pretty constant at regular city driving speeds.

I was wondering if this is a common thing with the hybrid ES or if I should stay away from this car. I'm thinking I'll need to test drive a couple more to see if I can hear the same thing.

jollick

It sounds like the regeneration process. Sounds to me like a turbine. It is very faint and not constant, only when regenerating power to recharge the battery. I happen to like the sound in my ES300h. It is a great car.

chromedome

It's the sound of the electric motors up front. The traction motor can get pretty loud if you're driving on battery power only. The car also sounds like a subway train slowing down when it's on regen as the traction motor brakes the car. All hybrids and EVs make these sounds, I wouldn't worry about it.

Vegasaurus

think of it as the sound of money desperately trying to leave your pocket but being held in!