Toyota Prius Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
Just got my new '06 Prius a few days ago and the salesman mentioned that I should wait 1k miles before using the cruise control.

He then went on to say that Toyota would never tell you that, but the guys in the shop recommended it. I'm not too sure why this would be, does anyone know if this is true? I searched the forums and didn't see anything about this.

Anyone ever heard of this?
 

·
Premium Member
Joined
·
2,815 Posts
Depending on the vehicle model, usually there's a warning that you should vary your engine speed during the initial break-in period (therefore you shouldn't use cruise control), so that's where the sales person is coming from.

However, that warning has been removed from the newer Prius. (I think it was in my 2001's manual, but I'm too lazy to go downstairs and check.) The eCVT keeps the engine at differing speeds, even with cruise control, so no real need to worry.
 

·
Registered
Joined
·
7,161 Posts
2004/2005 owner's manual says break-in is 600 miles. Main thing to control is hard braking, but excessive speed and acceleration should be avoided during that time.

In a normal car with set gear ratios, driving with a cruise control could create a rather constant engine RPM, especially an aftermarket CC workign off the tach (like my old Sears CC, boy did that work great).

But with the way the Prius works, engine speed is determined by power demand, and is not proportional to vehicle speed. If you climb a hill, engine RPM will increase. Decending a hill, your engine most likely will be off.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #6 ·
So I gather that there isn't one well defined answer since some of you are saying there isn't a break in period and some are saying 600m, etc.

Maybe a good rule of thumb would be to limit cruise control use until about 500 miles or so?

Seems like Toyota would put a statement about this or put it in the manual if it was a big concern. Wouldn't they want to cover their asses in case something can go wrong if you use the cc too early in the car's life?

I will proceed with caution in relation to the cc. :)
 

·
Registered
Joined
·
7,161 Posts
Page 202 of 2004 owner's manual, section 3, INFORMATION BEFORE DRIVING YOUR TOYOTA (so you can possibly find it in the owner's manual in later model years):

Break–in period

Drive gently and avoid high speeds.
Your vehicle does not need an elaborate
break–in. But following a few simple tips
for the first 1000 km (600 miles) can add
to the future economy and long life of
your vehicle:
* Avoid full–throttle acceleration when
starting and driving.
* Avoid racing the hybrid engine.
* Try to avoid hard stops during the first
300 km (200 miles).

I will re-iterate, the way the drivetrain works on the Prius, CC would not yield constant RPM like most other cars, and even the vehicle speed can vary +/- 1-2 MPH on occasion, especially during changes of load.

CC should not be a problem during so called break-in period. Besides, CC would not permit hard acceleration or hard braking but would promote gentle driving and depending on set point, avoid high speeds.
 

·
Premium Member
Joined
·
2,815 Posts
puppetmasta said:
So I gather that there isn't one well defined answer since some of you are saying there isn't a break in period and some are saying 600m, etc.
There is a break-in period for the Prius. However, the owner's manual for the current Prius does not mention anything about varying the engine's speed (i.e. not using cruise control) as is common for the break-in period for most other cars. Just to avoid racing the engine and no hard stops.
 

·
Registered
Joined
·
582 Posts
no break-in cruising?

This particular restriction during break-in has never made sense to me for Prius. Its gasoline engine speed is not constant even at constant road speed, because of the way the electric motors and planetary drive work.

Avoiding hard breaking makes sense, as does avoiding sustained heavy engine loading. The latter would occur in fast uphill driving or *really* fast flat driving.

Seems to me that this section of the owner's manual was drawn directly from conventional vehicles without being modified for the hybrid drivetrain.

DAS
 

·
Registered
Joined
·
7,161 Posts
After reviewing the break-in recommendations, which I posted, I don't see anything regarding engine speed variations mentioned.

However, it would make sense to allow the engine speed to vary. But then again, that's just the very nature of the Prius, which is why Toyota didn't mention it in the user's manual.
 

·
Premium Member
Joined
·
2,815 Posts
US 2001 Owner's Manual, Section 3 "Information Before Driving your Toyota," "Break-in Period," page 144:
Drive gently and avoid high speeds.
Your vehicle does not need an elaborate break-in. But following a few simple tips for the first 1000 km (600 miles) can add to the future economy and long life of your vehicle:
  • Do not drive over 100 km/h (62mph).
    Avoid full-throttle starts.
    Try to avoid hard stops during the first 300 km (200 miles).
So it would seem that the US Prius has not had the cruise control/varying speed thing, but it is the "do not drive over 62mph" limitation that is gone from the newer manuals.
 

·
Registered
Joined
·
7,161 Posts
It does still address the max speed issue, but it's not specific about it and not addressed in the bulleted section.

Page 202 of 2004 owner's manual:
"Drive gently and avoid high speeds. "

See my previous post for the rest of it.
 

·
Registered
Joined
·
95 Posts
Just a guess here...but given what people are saying about constant speed not equating to constant engine speed, I think that that whole line of thinking may be a red herring. Perhaps the reason more relates to the "avoid full–throttle acceleration when starting and driving" statement that is in the manual. After all, I have noticed that the cruise control can result in fairly full-throttle sounds from the engine if you ask it to resume speed or you use it going up a big hill.

I am still skeptical that using the cruise control would present a real problem, but my guess is that what the salesman was thinking of may have more been along these lines.
 

·
Registered
Joined
·
7,161 Posts
I find the opposite to be the case. CC is not very aggressive with the acceleration that I am often tempted to accelerate to speed myself, then set CC. If I am patient enough, I let CC do the acceleration.

Athough I can't state or prove this scientifically, it seems the most efficient acceleration rate is when the car consumes fuel at the rate of 20 MPG on a level surface. CC tends to keep to that rate. You can accelerate faster.
 

·
Registered
Joined
·
2,285 Posts
Sounds like the typical salesman that wants to sound knowledgable, but mixes up his (mis-)information. As Dan posted, on a conventional tranny (auto or stick), constant vehicle speed means nearly constant engine speed, which is said to be less than ideal for break-in. Certainly the CC will vary engine speedd with load, avoiding the problem. However, I defy even the most skilled driver to maintain constant engine speed in a Prius while driving in normal traffic! This is a problem that simply doesn't apply to the Prius, and the salesman should go back to school and learn a thing or two before opening his ignorant mouth.
 
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top