Break-in vs. Cruise Control

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

 

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

 

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.

 

I 3rd qbee42's recommendation.

 

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.

 

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.

 

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

 

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.

 

The manual on page 121 says this about "Breaking in your new Toyota"

"For the first 180 miles (300 km):
Avoid sudden stops.

For the first 621 miles (1000 km):
Avoid sudden acceleration.
Do not drive continuously in the low gears.
Do not drive at a constant speed for extended periods."

Obviously the dealer has 1000 km and 1000 miles swapped, but this is understandable. If he said "for the first 621 miles" you would probably think he was joking or was from outer space. :suspicious: :alien:

This section sounds like boiler plate, especially the part about driving continously in the low gears since this vehicle has a CVT and doesn't have "low gears" as far as I know. :huh:

By saying "don't use the cruise control" he has in effect covered "do not drive at a constant speed for extended periods." Of course with a Prius this will matter to fewer components because of the nature of the drivetrain's operation. (More boiler plate sounding.)

The part about sudden stops is very sound advice as with any new set of brakes (and/or a car you are not yet familiar with.) As for the rest I've never heard any really compelling arguments about how important any of it is.

I can come up with some theories about various components but I'm not sure they amount to much. Avoiding running the car hard (sudden acceleration) sounds reasonable. There are some parts that probably benefit from settling in under less demanding initial service rather than being under heavy load for their early cycles. Wearing down any major burrs, etc. might be less likely to wallow other parts out if it is done gradually to get rid of the worst part. Plus if you do an initial oil change at 1,000 you should get rid of any crud, burrs, or debris from assembly that has fallen into the oil sump.

And of course from Toyota's perspective if you avoid hard acceleration for the first "621 miles" you are less likely to break any marginal parts right away...perhaps giving them some minor relief if a part goes belly up later, like say within 621 miles after the powertrain warranty expires.

 

I read yesterday about someone who flew from San Diego up to SF Bay Area to get their Prius ... then drove it home on the interstate for break-in. I've heard it is best to avoid constant speeds on a new engine, so I wouldn't do a long freeway run when new.

Saw a sedan being test driven yesterday. They stopped on the loop and floored the car off the line.

 

Does that quote come from a *Prius* owner's manual? If so, which model year?

 

Yes, Prius manual for 2008...not even a month old yet.

 

Well, I can certainly see the problem with that info - What gears!

But alas! I have a 2008 and on page 121 I see the same thing.

Things that make you go hmmmmmmm.