Break-in vs. Cruise Control

[MikeInPoulsbo]

Hi,

We took delivery on our Prius today (2008 pkg 5, Silver Pine Mica). I have a question about break-in. The dealer rep says we should not use the Cruise Control the first 500 miles. He did not indicate any other break-in issues but the manual does list a few. I am so used to using CC that this is going to take serious discipline staying off it. Is his recommendation related to the suggestion that the car not be driven at constant speeds for long periods?

[rigormortis]

just do what the manual says, some of those dealer reps say things that are completely wrong.

one of the ways to improve fuel encomy is setting the car at a descent speed to your liking, say 62, and leaving it on cruise control as much as possible. it will not only save you gas, but it will probably save you speeding tickets

undoubtedly a hyper mileage will chime in soon and say how its bad for fuel economy to leave it on cruise control full time,
but that will be considered off topic, heh

[qbee42]

Cruise control is fine. The theory about not using cruise control is that you want to run the engine at varying speeds during break in. With the Prius, the engine speed is not directly related to the car's speed, so using cruise control will not force the engine to run at a steady speed.

Engine break in is not the issue it used to be. Avoid wide open throttle, shake up your driving a bit, don't panic stop if you can help it, and all will be good.

Tom

[Shawn Clark]

I agree with qbee42's recommendations. However, you might want to try running without cruise control for awhile to familiarize yourself with how the hybrid system responds on the energy screen. The way the vehicle responds to the throttle is completely unlike anything you've ever driven (even though it might not appear that much different at first.) Having a long drive can give you some opportunity to learn how the hybrid system responds to different grades, speeds, battery charge, and throttle action. Looking at some of the tutorials about pulse and glide, warp stealth, etc. (perhaps making some printouts) could make the first long trip more useful. Even if you do go back to using CC you will be more familiar with how the vehicle responds and when it might be best to hit "cancel" and take over.

[mingoglia]

I 3rd qbee42's recommendation.

[litespeed]

While it would be very hard to measure affects of various break-in procedures...I favor the heat cycle approach....a series of short drives..20-30 miles with cool down periods between each cycle...varied speeds, no full throttle, no cruise control...for 1st 100-200 miles..after that..drive normally..with exception of full throttle...for 5-600 miles..then you are done.

[MikeInPoulsbo]

I thank you all for your responses. As far as short trips go that's what we do a lot of. I had anticipated poor gas mileage in my situation here -- 2-3 miles to our destination; down then back up a long hill; short stay at the destination; several stop lights. The MFD says I am getting 35 mpg in these conditions which seems pretty good to me.

[kittykat]

Ok, I have a further question about this. My dealer said I shouldn't use CC for 1000 miles. Not that I trust anything this dealer says. I just finished reading the manual & I didn't see anything in there about how long you should not use it. Where are y'all getting your information from? Thanks for the input.

[Whiteyprius]

Don't be at all concerned about CC. Drive it moderately, don,t stomp the throttle and all will be fine

[patsparks]

Originally Posted by qbee42

Cruise control is fine. The theory about not using cruise control is that you want to run the engine at varying speeds during break in. With the Prius, the engine speed is not directly related to the car's speed, so using cruise control will not force the engine to run at a steady speed.

Engine break in is not the issue it used to be. Avoid wide open throttle, shake up your driving a bit, don't panic stop if you can help it, and all will be good.

Tom

As usual Tom speaks words of eternal wisdom. Go for a run in the hills, that should bed things in. Enjoy the best engineered car on the market. No, I don't care if you are an engineer for Mercedes, I believe I am right.
Oh it is my belief from my days as a mechanic rebuilding engines and stuff that a couple of hard accelerations in the first 1000km will help seat the rings to the bores. Just don't allow the petrol engine to rev to red line.