Engine Noise and Responsiveness

[holycow99]

I'm in the process of getting a '08 Prius Touring Pkg #6 which is hard to find in this area. I finally found one in a town two hrs away. Yesterday, I went to pick it up but went home empty handed because:

1. the engine noise seems high when pushed trying to get up to highway speed. So far I have test driven three New Prius on dealer's lot. The first one, a '07,was noisy like hell when pushed. Second one was very quiet and accelerated quite well. The third one yesterday was somewhat in between the previous two.

2. the car is actually a pkg #5 w/ port-installed leather (w/ liquidcell). I was surprised to find that there are no leather on the door's armrest and steering wheel!

3. I ask for a cargo net. The dealer found out that they cannot just take it from another Prius as it requires to install the two upper hooks. As a result, I need to make another trip.

Okay, issues 2 and 3 are really no big deal but I'm really confused by the engine noise and responsiveness. Is it real or just my imagination? If real, what causes it? Could it be battery's charge level?

I ended up ordering a touring pkg #6 from the same dealer(I felt obligated since they held the car with 3 miles on the odometer for me so no one could test drive it for almost a week). I worry that what if this one comes in like the first one I test drove. Any comments? Thanks,

[donee]

Hi Holycow99,

I think you answered your own question. Being in a warmer climate, the AC will run down the battery when sitting. The car does not like charging the battery, unless its moving. What the highway acceleration test within a couple miles from sitting with the AC on ?

The car gives priority to battery life. Which means it is programmed to try to hold the battery mid charge. If the battery is down into the purple bars on the SOC (State of Charge) indicator (which is on the "energy" screen), it will run the engine pretty hard, if you need acceleration at the same time. As you were just driving the car for the first time, you might not have even been in this screen on the display, let alone noticed the SOC indicator.

In normal driving in hot muggy weather, its usually not a problem as the car is always moving, and it keeps the battery at mid point. In stop and go traffic, the battery gets down, but, hey, there is no need to accelerate very much either. Only the odd situation of a sitting in a dealer lot waiting for the next test driver, or at a rest stop on the highway with the AC on and stationary is where this is noticable. Parking in the shade is always a good thing, no mater which car you drive, of course.

[holycow99]

holycow, donee, I think you're right on. I did recall the second Prius (the good one) was parked in the shade!!! and the worst one was sitting under the sun in a hot afternoon.


Another possible factor is cold engine and the fact that acceleration occurred right after leaving the dealer lot.

Hmmm, maybe I should go get the car, instead of waiting for the ordered one which won't come until November?

Is the "liquidcell" leather really making the seat cooler than the factory-installed one(issue 2)?

donee, thanks for the quick response. I feel much better now.

[efusco]

The real bottom line is not to worry about the sounds you hear...the interaction b/w the battery and ICE vary. The ICE is governed to run no faster than 5000 rpm and will sound loud when it gets over 3500rpm or so.

You are using a lot of gas when it gets that high though, so when you can avoid hard acceleration like that do so for the sake of your fuel economy.

[richard schumacher]

It may also feel to you as though the clutch is slipping. This is perfectly normal: there is no clutch, and the engine RPMs are not a direct function of the road speed. It's just the engine running as needed to supply the power required at each moment.

[holycow99]

<div class='quotetop'>QUOTE(richard schumacher @ Oct 15 2007, 04:47 PM) [snapback]526028[/snapback]</div>

It may also feel to you as though the clutch is slipping. This is perfectly normal: there is no clutch, and the engine RPMs are not a direct function of the road speed. It's just the engine running as needed to supply the power required at each moment.
[/b]

Yeah, never driving a Prius before, I was completely perplexed by the great disparity in engine performance in three seemingly same new cars. Next time, when I test drive the Prius that I'm ordering, I'll make sure the AC is turned off and try to look for the battery charge level. You live to learn....

[a priori]

<div class='quotetop'>QUOTE(holycow99 @ Oct 15 2007, 09:40 PM) [snapback]526148[/snapback]</div>

Yeah, never driven a Prius before, I was completely perplexed by the great disparity in engine performance in three seemingly same new cars. Next time, when I test drive the Prius that I'm ordering, I'll make sure the AC is turned off and try to look for the battery charge level. You live to learn....
[/b]

Keep your eye on the SOC (State of Charge) of the battery. When I first picked up my Prius, it was mid-August, and the car had only been driven enough to get it to the gas station. They had just pulled it off of the truck, prepped it and gassed it up. They then let it cool with the A/C on. By the time I got in to drive it away, it was showing two purple bars. In fact, it took me a couple of weeks before the purple bars really went away. I don't think I've seen them now for a long time.

Some of this comes from learning to drive better, of course. At the same time, I think newer cars that have been sitting out will not be prepared to give prime HSD performance. Not to worry -- it will! I still haven't had a tank under 50 MPG (according to the MFD), while my calculated mileage is now above 53 for the lifetime of my car.

[drifty1955]

<div class='quotetop'>QUOTE(a priori @ Oct 16 2007, 12:09 AM) [snapback]526183[/snapback]</div>

Keep your eye on the SOC (State of Charge) of the battery. When I first picked up my Prius, it was mid-August, and the car had only been driven enough to get it to the gas station. They had just pulled it off of the truck, prepped it and gassed it up. They then let it cool with the A/C on. By the time I got in to drive it away, it was showing two purple bars. In fact, it took me a couple of weeks before the purple bars really went away. I don't think I've seen them now for a long time.

Some of this comes from learning to drive better, of course. At the same time, I think newer cars that have been sitting out will not be prepared to give prime HSD performance. Not to worry -- it will! I still haven't had a tank under 50 MPG (according to the MFD), while my calculated mileage is now above 53 for the lifetime of my car.
[/b]

Yikes! Couple of weeks to get the purple bars go away? Thats not right. I've had the purple bars a few times and the batt charges right back up to 3 0r 4 blue's within a 15 minute drive. Only see the purple bars now if I do something stupid like let the car sit with the air on for 20 minutes. In fact the longer I own the car..... now been about 2 months its become really easy now to achieve all green bars.Usually takes about a 25 minute drive even with the air on.

[a priori]

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 16 2007, 12:11 AM) [snapback]526209[/snapback]</div>

Yikes! Couple of weeks to get the purple bars go away? Thats not right. I've had the purple bars a few times and the batt charges right back up to 3 0r 4 blue's within a 15 minute drive. Only see the purple bars now if I do something stupid like let the car sit with the air on for 20 minutes. In fact the longer I own the car..... now been about 2 months its become really easy now to achieve all green bars.Usually takes about a 25 minute drive even with the air on.
[/b]

Yikes, indeed!! Now I see the reason for your reaction. What I meant to say is that the purple bars continuously or regularly reappeared. I would have three or four blue bars (no more) that periodically reverted to the one or two purple bars. I didn't see any green bars for at least five or six weeks after I bought the car. Now, I don't see the purple bars at all, and I regularly see five or six green bars come up. I don't know why the progression exists. Perhaps it has to do with the design of the car. Of course, it could just be due to my learning curve in driving the Prius.

Sorry for the confusion.

[Pinto Girl]

<div class='quotetop'>QUOTE(Drifty'sDad @ Oct 16 2007, 12:11 AM) [snapback]526209[/snapback]</div>

Only see the purple bars now if I do something stupid like let the car sit with the air on for 20 minutes.
[/b]

I must be *really* stupid...'cause I set the HVAC, and let the car sit for hours!

The Prius is actually one of the most comfortable road-tripping, "sleep in it" cars I've ever owned.

Set the HVAC, lock the doors, climb in back, and slip under the covers; the car will efficiently cycle the ICE and take care of itself all night long.

Biggest concern is hitting your head on the dome light when you get up in the morning!
:-)

------

Two purple bars indicates a SOC in the neighborhood of 40%. All green bars, about 80%...it's not like the battery is at zero when you're seeing the purple bars.