I live NEAR Chicago. Right now we are in the coldest part of the season/years. The day temperature has been high of 12 F to low of 1 F night has been around 0 F. For the past week. The wind chills are negative numbers. Half the week has been sunny half cloudy. We have had colder. It seems during the cold spell my MPG in my 2012 Prius C takes a nose dive. I get around 20 MPG. If I let it warm up it squeezes a few more MPG. I wish the Prius C had a temp gauge. Anyways it is only for about 2 weeks a year. Then my MPG goes back to normal. Any thoughts on this? The Prius C has about 75,000 mi, needs an oil change, and sits outside.
I'm 2 hours north of chicago by the lake and I got 30mpg last night on my 14minute (near 0 and probably below zero with wind chill) commute and 35mpg this morning on the same 14minute communte (I usually get better gas mileage coming home...more downhill? or not going against the wind) I usually just start my C up and go, no warm up (unless windows are frosted, but it's garaged from home, just not at work) and no I don't gun it if it's not warmed up, I just ease my C into the 55mph country roads then go 10 above posted (like everyone it seems and the sheriffs don't really mind 10 above). If you've ever watched or researched synthetic oil weight/viscosity, pretty sure the 0W still maintains it's viscosity at near 0 temps, so long as you don't gun it, engine should be fine in getting the needed lubrication. ***also have you tried grill blocking your C??? I use pipe insulation from menards (local home improvement store) to grill block almost my whole grill but compare that to the 16-20mpg I get in my odyssey (only drive it if there's snow, since it has newer tires)
Look into the block heater. It's a Toyota accessory, check with dealership, and on Toyota website, there'll be an installed price there, maybe a bit over $200 US?? Print that out for when dealing with dealership, in case they go much higher. The part is around $80, and it's doable, but NOT a lot of fun. It might be simpler to just let them do it. Look to plug-in for at least 2 hours. Also, assume you will forget to unplug, sooner or later: make sure the extension cord is secure and will pull out easy, and have your block heater cord VERY solidly zip tied to grill, and not extending long enough that it will drag along road. Test this. We got block heater install, eight-oclock-day-one, and use it semi-religously, year 'round, always aiming for 2 hour plug in before first cold-start of the day. And our winters are mild. Basically, it'll raise the coolant temperature about 20~30 degrees centigrade, above ambient temp. Dead of winter, our car will be shutting down a few blocks down the road, at the first red light. Without the block heater, it would still be at fast idle, makes a difference for sure. Good for the engine too: cold starts are rough.
I just got my Prius in December, so winter driving is all it has done so far, in a climate similar to Chicago (I'm about five hour west). My overall MPG so far is around 36, but on the coldest days and a 6-mile commute, I have been doing well to make it to 20. I'm looking forward to spring (for lots of reasons, not just the car!), so I can get a sense of what the Prius can really do. Mendel, I like the idea of a block heater. I had one in my previous car and over the years had similar good results to yours, though I only used it when the outdoor temperatures were below freezing. But currently there is no place to plug it in (apartment life, the car out in the middle of a parking lot). Someday... I am tempted to go ahead and get the heater installed.
