Prius Generations in cold weather

Get a black car - black absorbs solar heat faster.

You need to grill block a Toyota Prius when the temperature drops below 60F degrees.

On cleanmpg.com there is a FAQ article on winterizing a prius/hybrid at...

http://www.cleanmpg.com/forums/showthread.php?s=349e74d6181a59e6ec080b61e7f3ad37&t=17560

It sounds like Finnish Prius have a 400W Engine Block Heater(EHB) standard. If you can use an EHB - the optimal pre heating warm up time is from 30minutes to 90 minutes. After 90 minutes, the Return on Investment diminishes. Since you cannot pre-heat your car - I would suggest you look at installing additional engine hood insulation as an option.

2nd gen vs 3rd gen

If you get a 2nd gen Prius then you should get something to monitor the engine speed (RPM) and fuel consumption rate (GPH) like a scangaugeII or an Android Torque App if you want to optimize your fuel efficiency. The 2nd gen Prius fuel efficiency display is clumsy and primitive.

If you have a 3rd gen then you can get by with the onboard HSI display to optimize your fuel efficiency.

The 2nd gen Prius has a Coolant Recovery Heating System (CHS) -- atleast in the USA --but the 3rd gen Prius does not. The CHS keeps the Prius coolant warm for over an hour after the car has been turned off. The CHS makes the 2nd gen Prius more fuel efficient than the 3rd gen Prius when the driver does multiple short trips in sequence (where each min trip is only in less than an hour apart from one another). The 3rd Prius has an Exhaust Heat Recovery (EHR) system which heats up the coolant faster by recovering extra heat expended from the exhaust to heat up the coolant faster. Hence, the 3rd gen Prius tends to be more efficient when one is just driving one simple long trip. You can click on my fuelly.com signature to see my mileage log for the winters - please ignore the winter of 2011-2012 since it was very mild and the average winter time temperatures were way too high.

Even with hypermiling I normally get about 53 to 56 mpg (US gallons not Imperal gallons) during the cold winter days on my 3rd gen Prius on my 15.8 mile /60 minute commute to work in the cold mornings using 10% ethanol gasoline. It takes about 30 minutes to 45 minutes for the 3rd gen Prius ICE coolant temperatures to warm up to about 160F-188F degrees and reach 45 to 55 mpg. BTW - When I drive my 3rd gen Prius for less than 2 miles from a cold start in -32F degree temperatures , the Prius will get between 12 to 30 mpg. Short trips in cold weather causes the Prius MPGs to drop.

hope this helps

Walter

 

That isn't a necessity. Blocking simply reduces the burden on the engine, by limiting the flow of air and helping to retain heat. This is my 13th winter here in Minnesota driving a Classic (2001), Iconic (2004), Definitive (2010), and now PHV (2012). That benefit becomes quite obvious when you drive the plug-in, since the engine runs less.

Each generation has shown improvement. That's certainly not a purchase decision maker though. There are plenty of other differences to make that choice with.

As for an engine-block heater. I haven't ever used one. Obviously though, it does indeed help. But if you're like me, who's Prius is parked outside all day in temperatures well below freezing, the ability to warm up quickly unassisted is a big deal.

Usually about 10 minutes into my commute home on those brutally cold evenings warmth emerges from the heater, enough to start to feel comfortable. Of course, with heated seats, warming takes less than 2 minutes.

 

That seems like a long time to warm up. I have an Ultra Gauge and it reaches those temps in about 10 min. First 2 miles local then highway.

You didn't really mean -32F? Maryland isn't that cold.

With temps in the 30s in the morning going to work I have been getting about 54-58 mpg (display) on my 35 mile commute into work. On my way home lately, temps usually 45-55, my mpg is about 62-64 (display). It's the short trips that really hurt. Typically, I don't do too many during the week this time of year ... golfing has come to a screeching halt.

BTW - great job on the readability of your post!

 

As a fellow MN I can tell you that -32 was probably an accurate number a few mornings in the winter here (if you count the wind chill is can be lower than that every now and then

 

The description of your winter closely matches Anchorage, Alaska. My 2010 (GenIII) does quite well with about 52 mpg summer and about 43 mpg winter. I do have a warm garage to park in at night however. A few other members that do not have a garage suffer a bit more in fuel economy.
I think you would still come out ahead with the prius, assuming you got a good used one.

 

You are not a fellow MN, since Walter is from MD. If MD got that cold, the government would be at a standstill. Well I guess they are at that anyhow!

 

In my experience the "block heater" (400 W) is pretty much useless in our climate. Not really noticeable. I tried the one in Pearl (GII) and gave up on it. Pearl S (GIII) doesn't have it installed, so I didn't -waste- the $400 or so they charge for it.

You WILL need to block the grill. We use pipe insulation for this. Search the forum. There are lots of posts on it. It helps a lot speeding up the warm up of the engine. I recommend a Scangauge or some other OBDII reader with real time gauges so you can watch the coolant temperature.

Here in North America the GII has the thermos as you have listed. It was useless as well. At an ambient temp much below freezing the coolant in the tank by morning is not very warm and there isn't much of it. My observations with the Scangauge showed it raised the coolant temp by perhaps 5-10 deg. Not very effective when it starts at 0 C or lower. Driving a block does the same.

In my opinion both the block heater and the thermos are useful in more temperate climates - below latitude 45 deg. in North America or along the coasts.

The GIII here has the exhaust heat recovery device, and it -may- speed up the warm up cycle. Proper grill blocking is easier, cheaper, and probably more effective (keeping the cold air wind out of the engine compartment as you move).

You can expect the following mileage:
GII - summer - 4.6 l/100 km winter - 6 to 7 l/100 km
GIII - summer - 4.4 l/100 km winter - 5 to 6 l/100 km

The car works best if your trips take 20 min or longer. It won't warm up sitting and idling when it's real winter, as you and I have (actually I think it's a bit colder here). You will find the car cold inside until you have been driving that long, though the GIII has been noticeably faster, perhaps twice as fast to warm up.

The reason for all this is the engine is just so darn efficient, and produces little waste heat. Add to that the fact it will shut off when not needed, and you will find the coolant will run in the 60C temp range for a long time in the GII, but the GIII seems to reach 80C in the same time and gives better cabin heating.

Oh, and I only noticed the effect of the two electric heaters in the A/C system once, on a day when it was above freezing, perhaps 10C. Otherwise they are ineffective in our climate.

 

I forgot to mention, that I am completely lower grill blocked. I have been since about 9/20 here on Long Island.

Walter Lee - are you grill blocking? I just assumed you were, since you are up on these type of matters.

 

HAHA, I misread that state abbr... my bad nothing like putting your foot in your mouth within your 1st couple posts. I should blame it on my laptop screen but with 20/20 vision I don't really have an excuse.

 

Yes. I'm blocking both the top and bottom air intakes right now. I monitor my coolant temperature with a ScangaugeII FWT Xgauge. Because I'm hypermiling my Prius - I don't run the ICE as often as someone who isn't hypermiling - hence it does takes longer for my Prius' gasoline engine/coolant to heat up. I'm sure if one drove the Prius like a normal car - it would heat up faster (but at the same time it wouldn't be optimizing the Prius' fuel efficiency) I'm getting about 59 mpg overall over 32 miles per day commute right now with my tire pressures set at 44 psi front and 42 psi rear. The average driving temperature is between 30 to 45 degrees Fahrenheit here in DC Metro Area. Oh yes, that "-32F" was a typo - it should have been "32F " - I miss that one. It sounds like taraja(the OP) knows about EBH but he doesn't have access to a garage/electrical outlet to plug the Prius' EHB in so it's basically worthless standard feature for him - hence - I suggested getting a black car and maybe upgrading the Prius' hood insulation + grill blocking. You can buy automotive grade hood insulation over the net but you have to cut and install it yourself... I've been thinking of doing that myself....

I forgot to mention that the Prius fuel efficiency depends partly on using Low rolling resistant (LRR) tires and that taraja should make sure that if he buys a used Prius to make sure the tires are LLR tires if he wants to optimize his fuel efficency. Unfortunately the downside to LRR tires is that often they dont perform as well in ice and snow as good conventional performance tires - something a driver in "snowy Finland" might decide is not a good engineering trade off.

 

For me here in cold, snowy Vermont USA, I generally drop 5-8% overall MPG in winter time. That's a combination of high friction snow tires and the consistent low temps. We use the heat and defrost plenty and we are not hardcore hypermilers.

 

The Nokian tyres are very LRR. One of the best according to the charts. My favorite. Pearl wears the WRGII. Pearl S is on the stock tyres, which work very well when parked in the garage for winter. Actually they worked fine for the few days I tried the car. Now the snow is too deep and I refuse to plow the roads for the city with Pearl S! So I burn about 2-2.5 times as much fuel driving the FJ Cruiser. Good for our local economy, bad for the environment.

 

I think I'm going to also try blocking the upper grill, now that the morninga are pretty much in the 30s. I'll keep a close eye on the temperature with me UltraGauge. Worst case if the temp gets too high, I pull off to the side of the road and just pull it off. No harm, no foul!

 

I'll let others argue about grill blocking or not. In New Jersey, not that cold a place, it doesn't seem that necessary. But I've never used it, so who knows.

What I have heard though, is that the GEN 3 traction control is better than the GEN 2. Something about if a GEN 2 is in a place where the car has to be rocked to get free, the traction control tends to prevent the driven wheels from spinning. The GEN 3 has, apparently, software changes that allow for better wheel spin/rocking.

Turning traction control off on a GEN 3 is possible, but time consuming and difficult. (Open this door, close that door, hit a button twice, stand on one foot and blow a nose, that kind of thing - I've got the instructions around here somewhere. )

KBeck

 

I have blocked the grill on my prius cars for going on 8 years now and it does make a diffrence. Under 50 degrees I block the bottom 1/2 of grill, car warms up faster and helps hold the heat longer. Really helps when it is -20 degrees and below!

 

Here on Long Island, I have been blocking my lower grill since late September and I just started blocking my upper grill this morning. It was 27* when I started out for work and 39* when I got there an hour later. According to my UltraGauge the highest temp it reached was 197.6* and that was only for a few seconds at a time. It literally took my 5 minutes to cut and fit my upper grill.

For such a cheap and easy retrofit, everyone should be doing it ... even in NJ!

 

If the Prius is driven longer than 30 minutes at over 50 mph, you shouldn't grill block your Prius. My 2010 Toyota Prius stability sensors are very sensitive - and just joustling around in the driver's seat can turn it on.

 

Can you please explain in more detail?