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So about a week and a half ago we picked up another Hybrid, a 2008 Prius.

I've had my HCHII for a few months now and absolutely LOVE it. Since it's gotten colder here in Upstate, NY I've definitely taken a hit in the MPG category, but still well ahead of my old Honda Civic LX.

So, back on track...I've been driving Rochelles Prius here and there when she lets go of it, and I can't seems to get above 44 MPG at best, when I could easily be at 50 (cold weather) with my HCHII for the same trips.

Is there something I'm missing with this car? I think a large part may have to do with me trying to drive it like my HCHII...which it's not. I try my best to keep it in electric when creeping from stops, which it does great!

Should I have posted this in the Pirus Forum?

Chris

Hi Chris
I have 06 HCH2 and 06 Prius and I get better results in the cold with my HCH2. I do better with the Prius in warmer weather. I prefer driving the HCH2! I'm glad my wife likes the Prius. She does better with the Prius. Both are very good Auto's. I'm happy and she is happy. H

Hi Harold,

Thanks for response.

I agree with the "I prefer driving the HCH2" :-) I feel almost like I'm driving a small Minivan when in the Prius, but the seats in it are nice and soft :-)

As for the Prius, when Rochelle started looking for something to replace her '01 Civic, she was set on picking up a Civic Hybrid as well, once she test drove a prius with package 6, she was in love...which I'm glad because she prefers to get in the car and drive which I think the Prius does extremely well, so far she's in bliss :-)

I really cannot wait until the summer weather gets here to see what each of these bad boys can do,

Hypermile wars '11 begin SOON!

Chris

Hi Chris;

Congrats on the 08 Prius. Excellent choice!!

Yes, I also concur with Harold. In my experience, the HCH-II has always been the better winter FE car especially when compared to the second generation Prius.

However, the third generation Prius has caught up with the HCH-II in this department and can at times be an excellent performer provided that we drive it well and have it well setup.

What I would suggest is that you prep the 08 Prius for winter operation (http://www.cleanmpg.com/forums/showthread.php?t=17560) and don't forget to check the tire pressures, level of the oil and its weight/viscosity. On this last detail, I have been very successful with 0W20 on the 2nd gen prius so I would recommend you do the same and the winter mileage will definitely improve.

A block heater is a BIG help on the Prius too.

Cheers;

MSantos

OK, enough about how great the HCH-II is. ;)

Two things happen to the Prius when it gets cold. One, it takes much longer for the engine to come to operating temperature. A coolant temperature of 70C or higher is needed to get to stage 3 (which means the engine shuts down on a glide at 35mph or above) or to transition to stage 4 (where the engine shuts down at every available opportunity...a brief stop while idling is required to get there). That can happen in just a few minutes during the warm months, but sub-freezing temperatures can delay warmup interminably, especially in an urban environment. (The engine does not warm up effectively at idle...it has to be driven.) Grill blocking goes a long way toward shortening warm-up and a EBH obviously does even more. Cabin heat can be a huge demand, too, and often forces the engine to idle when coolant temps are low.

The other thing that happens is that the system changes its behavior to protect a cold battery. High current could damage cold cells, so charge and assist can be limited to a small fraction of normal capacity. The battery can warm itself up eventually, but that takes a long time. I think this is much less important than engine heat management, especially if the car is driven efficiently (without much need for regen/assist).

If it makes you feel any better, I'm only showing about 49mpg right now and I'm working reasonably hard for it. It's cold!

OK, enough about how great the HCH-II is. ;)

Two things happen to the Prius when it gets cold. One, it takes much longer for the engine to come to operating temperature. A coolant temperature of 70C or higher is needed to get to stage 3 (which means the engine shuts down on a glide at 35mph or above) or to transition to stage 4 (where the engine shuts down at every available opportunity...a brief stop while idling is required to get there). That can happen in just a few minutes during the warm months, but sub-freezing temperatures can delay warmup interminably, especially in an urban environment. (The engine does not warm up effectively at idle...it has to be driven.) Grill blocking goes a long way toward shortening warm-up and a EBH obviously does even more. Cabin heat can be a huge demand, too, and often forces the engine to idle when coolant temps are low.

The other thing that happens is that the system changes its behavior to protect a cold battery. High current could damage cold cells, so charge and assist can be limited to a small fraction of normal capacity. The battery can warm itself up eventually, but that takes a long time. I think this is much less important than engine heat management, especially if the car is driven efficiently (without much need for regen/assist).

If it makes you feel any better, I'm only showing about 49mpg right now and I'm working reasonably hard for it. It's cold!

Hi Tim,

I can't wait to see what he prius does in the warmer months...I think the MPG potential of trading her I-90 ride to work and using rte.5 instead will be justified if the MPG swing is really that large from warm to cold weather. Now the extra 15 to 25 minutes will be the hard part to convince her of ;-)

This is a dream come true having each of these in the Driveway ;-)

Chris