First Snow, low temps...

It will help reduce the ICE warm up cycle but if ur running the heater it will keep the ICE running.

U might also want to look at the grill blocker

 

Keep checking tire pressure too! Sudden cold temps means you're losing air pressure.

 

I had ours plugged in yesterday for about three hours before start up. Tw0 hours is the practical limit for raising temp's., but...

Anyway, immediately after startup cooolant temp was showing around 100 degrees Fahrenheit, and within a couple of minutes (just backing out, getting out of our cul-de-sac) was up to 120 degrees. That rapid rise is likely due at least in part to the coolant temperature getting more homogenized, with circulation.

Ambient temperature was around 50 degrees Fahrenheit. As that drops so will the block heater results I think, but you can typically count on it to raise coolant temperature by 40~50 degrees F.

The temp. observations were with a ScanGage.

BTW, we got ours installed by the dealer, when we purchased the car. Installed they charged us $400, pretty steep. I might have taken it on myself, if I was doing now. From what I've heard/read it's doable, but a bit of a struggle.

You should really look into grill blocking too. There's a Prius 3rd gen grill blocking thread here, not sure how applicable it is to the C, or if there is a similar thread for yours:

2010 Prius Grill Blocking strategy | PriusChat

It likely can't hurt (inspires confidence, eh) to block just 50% of lower grill. If you've got continuous slats on the C, 1/2" plumbing pipe foam insulation is very effective. The 1/2" refers to the pipe diameter: the OD of the insulation is maybe 1.5".

You can also use that stuff to reduce heat from escaping through the hood. This is 3rd gen Prius, but something similar might work for you:

 

Now today is getting colder still for North Dakota (15 F is the high, 8 at night in Bismarck), how are the MPG's holding up in Minot? I had trouble just getting out of the apartment complex driveway today (nearly got stuck a couple times). I think you guys got the worst of the snow up there. Bismarck got 3-4" from that storm, though that wind doesn't help any . Are you going to try that grill blocking thing mentioned on the other forums? I would like to see if that would help at all if you would be willing to try that.

 

What kind of tire slips are you seeing in snow? Is it more agressive than the regular Prii? The wife's hatchback simply goes limp at the first sign of tire slip.

 

If the temps on the ocean were what we get here, maybe you could drive there . Wouldn't be a whole lot different than driving to work these last couple of days. Well, according to the people so far that have grill blocked, its only a couple of minute mod that costs pennies on the dollar, might be worth the investment if it works. And as long as you don't live on Mauna Kea, you'll probably be fine as far as snow is concerned (wish I could live in a temperate climate again ) . Thanks for posting your results.

 

Not really.

All-season and summer tires lose pliability in cold temps and increase stopping distance fairly dramatically at temperatures below 45F. Just saying.

 

I agree, drive like its winter, and you probably wont see the difference in tires. To people who only experience snow when they drive up to it or live in an area where it snows but warms up enough to melt it, then the sudden shock of driving on wintery roads may save some headaches. I am curious though if there is a difference when driving on ice, or icy pack snow (when it heats up enough to melt all of the snow around the packed snow, but the packed snow remains and re-freezes). That stuff is annoying, and generally means that it takes more time getting going from a stoplight. Don't know if its $150+ a tire annoying, but would be nice to have more traction in that case. I would love to drive on the snowy roads they showed compared to winter roads here.

 

Snow tires are not a scam. Traction is everything, and "all season" tires don't have anything close to the traction of snow tires in below freezing temperatures. All you have to do is bump into another car or slide off the road and you have paid for snow tires. My favorite winter tires are the General Altimax Arctic and Bridgestone Blizzacks.

Last year as I drove a snow covered interstate to work, I saw a pickup truck come on the to the road too fast for conditions. He was what I call a "shooter". There are two types of drives that I don't like. Some are shooters (drive like they are in a Nascar race), and "slugs" (could not catch a cold and merge on an interstate at 45 MPH). Well, this shooter guns the engine to get to the left had lane just in front of me. The tail of the truck came around quickly and his head lights were pointed right at me. With snow tires on my car I made a quick maneuver into the right lane and as I went by, the shooter was grinding up the passenger side of his truck against a center guard rail. Those snow tires paid for themselves that morning.

 

Also, after the initial outlay, for the snow tires and extra rims, you will be extending the life of your regular tires. Burning the same amount of tread yearly.

 

You may also save a life. Tires are the most important object on your car. Why mess around when your life or someone else's is at stake? I find it inconsiderate to drive on unsafe tires which includes tires worn past 4/32s when it's wet out.