Pre-collision system activation

Congrats on your new Five!! BTW, can you tell a difference in road noise or traction b/w the two tires (Michelin vs. Toyos)?? Thanks because these two are my prime choices.

 

After two weeks of driving, I am quite confident to say that the Toyos are quieter. At first I did not notice any difference. But then I noticed that I did not have to turn the volume of the radio up when I got on the freeways (55mph +). I used to turn volume three numbers up (17 on local road and 20 on high ways). Now I can keep the volume at 18 all the time. I kept the pressure to 36/35lb/psi on both sets of tires. The rides feel similar (btw, how do you tell the traction differences?). I heard that the Michelin has longer wear then the Toyo. It could be true because my Michelins still looked like new when the car was totaled at 22,414 miles. I expected them to last at least another 22k miles. I am not sure about the Toyos, which has a wear rating of "300" on the wall.

 

Thanks so much!!! Looks like i will be going with Toyos because i hate noisy tires! At 17k miles, my Toyos still look brand new...so, i am really hoping that the "300" treadwear rating is an underestimation!

Thanks again for your 1st hand experience with PCS and info throughout this thread.

 

How's your fuel economy between the two Prius V's? I see everyone getting 50+ on average and I'm lucky to get 45 on mine. The only possible way I can get 50 or higher is by driving 65 or under on the highway (or maybe a lot of city driving longer than 10 min trips, which i rarely do. Under 10 min = 40mpg for me, highway or city). Going over 65-67 on highway, mpg's goes off a cliff.

As for as PCS, mine has activated several times in near misses, but never once do I recall it automatically putting on the brakes. I don't think its disabled either because there's no "PCS" on the dash. Perhaps if the system senses that you have already started to apply the brakes doesn't slam them on? I think in most of the cases I was already in the process of braking at the time the car seen the issue and clicked on the seat belts.

 

I believe there are multiple stages to the PCS; if you're in an accident, I believe it will tighten the seat belts before it slams on the brakes, but since I haven't been in an accident, I can't say for sure. I do know that it also uses your treatment of the gas and brake pedals as inputs, though; if you quickly switch from the accelerator to the brakes (as you might for a near miss), it will tighten the seat belts and prepare the brakes, the same way it would if it saw an impending crash with the radar. It will also amplify brake input in these cases, as people often don't (or aren't able to) step on the brake fully in an emergency.

 

The only difference betweent the two V's is the tire (Michelin vs. Toyo). It's too soon to compare because the new one has only 1000 miles. But the first one had average about 46mpg (by hand calculation, not the trip computer). I drive 25 miles one way to work everyday (half high way/half city roads). In warmer days, I could get as high as 52mpg, but in the winter only 45mpg. The new car so far has 50mpg within the first month.

I did not have time to hit the brack in the accident because the other car suddenly appeared in front of me at the intersection. I can't verify if the PCS applied the brakes for me or not. Perhaps it did not have time to respond either. But certainly the seat belt was locked before the hit.

 

Ok heres a new one guys. I have been interested in how the pre-collision system works because its peace of mind to know how you and your car will coordinate in an emergency.
Plz donot try this at home!! Or on the road. It's very risky.
I saw the video with the cardboard boxes and was not convinced because it came wayy to close to be able to detect the boxes.
I did a couple experiments.
I drive on the highway everyday 90 miles. So I see a broken down car sitting on the edge of the white line since 2 days. 3rd day I slowed down and set cruise for 62 mph with radar distance as short. When I was about 500 feet away I went outside the while line for a couple seconds just to be behind that sitting car. No activation of pcs or even drcc brakes !! I was about 20 feet close and I had to pull back in the white line. That was scary.
I came home and read in the manual that pcs does not detect stationary objects! How was that cardboard guy able to pull that off? If you notice he didn't use cruise control. Is that why it worked? U think maybe pcs does not work when drcc is on?
But then again yesterday , I was cruising at 70 on the highway at about 5 pm. So it is slightly heavier traffic at that time. I had drcc at short distance again. Traffic in my lane started slowing down and my car also started slowing down keeping the distance but then they guy in front of me was fully stopped and I was sure I was going to hit him if I don't apply brakes soon. But on the other hand I really wanted to see what the pcs would do. At this point I took a big risk. I didn't apply brakes and the system started flashing and beeping with faster beeping. (exactly like the one with the cardboard guy). The car did NOT slam on the brakes but they were quite hard but I knew i was gonna crash within 1 second. The seatbelts did not qinch. I had to eventually apply brakes but then I noticed that the braking system helped me by applying extra force but I had to move my car onto the service lane in order at avoid the collision. But the car came to a complete stop when I applied some brake force.
So I conclude that pcs only minimizes impact but not slam on the brakes like the Mercedes "distronic plus" system.
I will redo the cardboard experiment myself with and without cruise but I want to have the "clear" bumper bra installed first.

 

Chris, you have balls of steel!! Damn...keep us updated with your experiements...and be safe!

 

I would have not done such things if I didn't have a 17 year fast driving experience behind me. Yes I've been driving since 94. I drove in India's densest and craziest places for 9 years! Without a single mis-hap( my God prevent everyone from any mis-hap).

 

Solution would be a vision-based system.

 

That's not the PCS working. That's just the DRCC slowing down the car. The beeping you heard is the DRCC too close warning. If you had look at the dash, it's the DRCC distance flashing not the PCS's brake warning flashing. I had that a couple of times. I've complained about the audible warning sounding the same here http://priuschat.com/forums/gen-iii...ing-down-prius-complete-stop.html#post1293759

 

Ya guys you maybe right about the cruise slowing down but today I tested it again and it showed blinking car first with slow intermittent beep and then when the car got too close, a fast intermittent beep and said "brake" in green and black flashing but I had the cruise set again at shirt distance.
One problem I am having is that I can't feel seat belts retract at all. One reason could be that the fuse is blown that gives power to the seat because my lumbar support button is also not working. Could there be a link?
I'll check the fuse tomoro.

 

pcs activates when you are about to crash, so what you got is radar cruise control activation,not pcs... hopefully you dont feel pcs ever working


so to confirm, pre-crash system works only before actual crash, it doesnt stop the crash it helps you make it less painful

 

Ok guys I quit!! I have had 4 close encounters uptil now(on purpose). Only today I saw the orange pcs light blink for the first time and a very fast beep as I approached a car on a red signal. Please don't Try that. It was just too close so I had to step on the brake. But I must say that when Toyota says that the car "primes" the break in such an emergency, it really works very well. The car completely stopped within 12 inches. I was at 27 mph when pcs started screaming. I guess I can never get to the third stage with the belts. That cardboard experiment is a must do for me now.

 

Tideland, I've tried that few times above 40mph, above 50mph and above 60 mph too. I've release the accelerator very quickly and tapped brakes very strongly. Nothing ever happened. I just can't get the car to "scream" on the brakes. I guess the brake system is too advance and it just slows down tremendously.
It's just nice to know how and when they work

 

Yay!!! I did it!! Thanks tideland! It worked over 50 mph. But not 40.
Bit here's the trick (make sure there's no car in front of you)
Bring your car to 35, and step fully on the pedal. The moment the car reaches 50+ mph, release the pedal very quickly and tap brakes upto 50 % capacity for half a second. YOU"LL FEEL THE BELTS! (I'm still excited) I don't know why, it's just belts after all!
But if you have your foot half way down the gas pedal and you do this, it will not work. The gas pedal has to be depressed more than 50 or 60 % I guess. And make sure you release it very quickly to press on the brakes. Make sure there's nobody behind you either.
But im glad I know the system works now (since i bought the car used) and dealer had no idea what is a tech package !) that's why I had a doubt on my pcs and belts but now I'm satisfied.
Thanks tideland !!