Good Day everyone out there!!!!
I have had my Prius since March of this year and I love it. Averaging 53 miles per gallon. But as winter is approching I know that I'm going to loose some MPG. Does any one have any sugestions on cold weather driving? Should I warm up the car for a few minutes before I start out in the mornings?

I was also wondering why the MPG calulation if different when you do by hand as to what the car montor says? My last tank I went 569 miles and filled up the tank (it was empty and the square was flashing) and put in 8.990 gals the car said 59.5 MGP my calulation 63.93 why the big differance? It was my best tank since I got the car and did all my driving in town.
Thanks for your help.

 

Welcome to the CLUB!

Engine block heater is a good idea. Also, you might see if you can do the first 1-2 miles at a slow speed to really let the ICE warm-up before putting a load on it. Warming on the driveway is not a good idea unless your using an engine block heater.

You might take a quick read of the FAQ but the simple answer is variable sized, bladder in the tank. But there may be a fix, if you're willing to risk it.

It looks like if you carry a small, spare can when you get down to one block and run the car out of gas, the bladder problem seems to go away. At least that is what appeared to have happen with my 03 Prius. One caution, I'm always within 20-30 miles of a gas station so I know my 1 gallon can will get me to a pump. You may want to carry a little more if the distances to a pump can get further than that.

Bob Wilson

 

As the bladder shrink with the falling temperatures, you'll be putting in less as a "full tank" hence the calculated number will be higher tha the MFD number. Hopefully the reverse will show when spring comes along and the bladder expands and you can put in more fuel before shut off.


As for winter driving tips

- install a block heater

- install foam insulation to the upper grille <15°C/59°F is a good start (technically you can start when the daytime highs drop below 20°C/68°C but without a scangauge, I wouldn't risk it and 15°C/59°F gives a nice big buffer. The lower grille can go in < 5°C/41°F. We use the pipe insulation (I think I'm using ½ inch.. gotta double check) from Home Depot. Cost: < Cdn$2 after taxes

- Be careful as the Integritys wear down. They're ok for the first winter and maybe the second (depends how many miles you put a year) but after 50% wear, they're much less grippy in the cold and snow.

- Get to know VSC. After the first snowfall, go to an empty parking lot and do some lane change manoeuvres and ABS braking. Simply knowing how VSC will react will help you understand what to do in an emergency.

- Clean the headlights of snow and ice regularly.

- If possible, clear the wheel wells of snow, ice and crud (whether you have mudguards or not) especially the rear wheel well. It has a tendency to collect quite a bit of stuff.

- Be aware of the Prius' low ground clearance and avoid any chunks of ice even if they seem small. The Prius (esp. if there's 2 or 3 people in the back) will hit it

- The rear defroster uses the most electricity (even moreso than the headlights) so if for whatever reason the 12V battery is running low, shut that off first.

- Remember to use the rear washer once in a while to make sure there's fluid in there when you need it. In fact, just use it right now after reading this message and just make sure that there's washer fluid running through the lines.

That's all I can think of for now

 

I used 3/4" foam in the upper grill, and I'd say it's safe there below about 25C. I used 1 1/2" foam in the lower grill, or perhaps it's 2". I'd say it's safe there below 15C (even at 20C ambient coolant only got to 95 C peak, and only then on the highway). But I do have a Scangauge II and wouldn't have tried it without -knowing- what my temps were doing. Also, keep in mind I can't monitor the electronics coolant loop, so perhaps being a little conservative is a good thing.

I am still amazed how little heat this car generates. Even with both grills blocked and 18C out, the car will cool below 80C at lights.

 

Well it is an aluminium block