How can pulse and glide be bad for engine?

The claim probably comes from the traditional view that starting is hard on engines. Obviously, the Prius doesn't start its engine conventionally, as it starts and stops all the time on its own. Pulse and glide only exaggerates what the Prius tries to do on its own.

Tom

 

The only streatch I can imagine the newbie meant might be in reference to pollution ... again, being quite a streatch, and really only applying to PHEV's. Here goes, as I've heard the concern: If the car is hardly running, then it doesn't warm up enough to adequately burn off pollution particles. The theory also brings up concern about lubrication ... where the thought is, if the ICE isn't running, then it must not be getting enough lubrication, which must cause pre mature wear. It's not really a P & G concern. It's more related to running with more EV power.

 

Did you ask that of the junior member? I'd be curious to see the response.

 

qbee & Jimbo,

You can ask him yourself. The post okie is referring to can be found here:

http://priuschat.com/forums/showthread.php?t=41525

 

I believe what the junior poster was suggesting was the old axiom that engines incur 90% of their wear in the first 5 minutes of operation.

In the old days this was somewhat true in the old days. In the old days, cold starts needed a rich mixture (choke) to start a cold engine, causing potential for oil dilution as well as other problems. In a cold engine the internal parts (pistons, rings, bearing etc) need to warm up to expand to their design sizes to seal and properly.

The Prius is very different. First, with modern fuel injection the amount of enrichment needed for cold starts is reduced, but more importantly, because of the way the Prius holds the heat in the coolant, it is not really "cold starting" each time it starts. As an engine spins, it really doesn't care whether it is burning fuel to turn or just being dragged along by the wheels to turn.
In the case of the Prius, above 41 mph, the engine is just spinning along for the ride if no gas is needed. Most cars burn a bit even coming down a long hill with the throttle totally closed.

Perhaps this clears up a bit of misconception,

Icarus

 

Thanks! I searched around for it quickly during my lunch break but couldn't find it. Meanwhile, Evan beat me to it.

 

I think it was Consumer Reports, that posted on the net their continuing reliability study. In it they stated the Prius was the "most reliable family car".

That doesn't help you, of course, but mechanical/electronic contrivances DO fail. So relax, let the warranty handle it, and be assured it will probably not fail you again, once they fix it. What you ended up with is called "infantile failure". The most failures occur early or not at all until the unit is very old.