Please post your winter G1 Prius tips here!

Tire pressure suggestions would be brand-specific and I don't know about yours. Leave the transaxle oil as it is, unless you are due for a fluid change. Many people use 0W20 synthetic engine oil. Even though it is not specifically recommended by Toyota, the used oil analyses all look very good.

The car starts like a champ in cold temperatures. However if your 12 volt battery is already old, cooling that thing way down may make it too weak to perform its (small) job. A small jumper battery is a fine acessory.

There is an electrical block heater available but I have no experience with that. It is described elsewhere in PriusChat. In fact the only winter prep I did was block most of the front of the radiator with cardboard. In 01-03 Prius there is a convenient space to slide it in. Behind the central vertical metal brace, and it rests on a lip at the bottom of the radiator. For the temps you will probably face, I don't think there could be such a thing as 'too much' cardboard in there.

Unnecessary to tell this to a winter expert. but if you preheat the car for a few minutes with the rear glass heater on also, most of the ice will just slide off the glass. But tricks like that and -30 driving in general will eat up the fuel. Expect a small decrease in mpg

 

3 winters in Minnesota, I did absolutely nothing to prepare my 2001.

Kind of boring, eh? The Prius just fired right up... even after sitting out in that horrid cold all day while I worked. For more heat, you could block the grille. But that's totally optional and something I didn't do. To reduce the startup MPG penalty, you could install an Engine Block Heater. But I didn't do that either.

Lots of photos available on my website, by the way. For example...

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I suspect you bought this car used? How many miles? Where was it bought?

I bought my 03 Prius used in October and our normal, cool winter started six weeks later. This led to my first transaxle, cold weather testing and change. However, I am curious if you might have a shallow hill near by that you can do cold-weather, rolling tests?

Our winters are so mild that I seldom get a long and hard enough freeze and after 3 years of incremental improvements, my test route is now too steep, my car does not come to a stop. Three years ago, it would come to a stop at temperatures under 35F. Now, it rolls all the way even if I start half-way down the slope.

If you have a shallow slope hill close to home, you could conduct some baseline tests and then try replacing your Type T-IV oil with Type WS, the current model oil. I've looked for equivalent transaxle oils and Type WS is a very high quality turbine oil. It really is good stuff! Worse, if your Type T-IV is worn, it really is bad news.

Block off the lower bumper inlet and don't worry about it until the temperatures get back to 80F.

A block heater will bring your engine temperature up about 20C in an hour. After four hours, it can bring it up to 28C. One hour is about the break even point as the gas engine rapidly adds heat. But a 20C boost can make a significant contribution if you learn to drive the warm-up cycle.

Check the message archives for "Ken" and "warm-up stages." It would be very helpful if you could rig up a coolant temperature gauge. I have one and this is my cold weather protocol:

• below 70C coolant - speed is around 25 mph and I use "N" as much as possible. In "D", even at idle, the engine burns about 30-40% more fuel. But in "N", the engine idles at the most efficient fuel efficient burn rate.
• reaches 70C coolant - look for a chance to stop, sit in "N" for about 10-15 seconds, and shift into "D" so the engine will "autostop." This puts you in the final S4 stage, full hybrid mode, and ordinary hybrid rules apply.
• last 2 miles, 30-35 mph - you want to maximize your hybrid EV mode driving to your destination. This will let you use the stored energy in the battery to maximize your trip mileage.

Now you live in an area with much colder temperatures than North Alabama. It turns out there is a way to trick the engine into thinking the coolant is 70C once it has reached 40C. Below 30C, the engine can choke-out and die. Once it reaches 40C, it works perfectly fine although the emissions might not be so good and you'll want to keep the oil clean.

You already know to:

• keep oil level under "F"
• tires at maximum side wall
• 4 wheel alignment (requires shims for rear wheels, camber bolt for front)
• clean throttle plate in fall and new engine filter

Seriously, if you have a shallow hill that with temperatures under freezing you can do a hill rolling test, it would be a good idea to plan on replacing the current Type T-IV with Type WS and saving a sample for oil testing. You'll get immediate feedback from the hill rolling test.

Bob Wilson

 

It is more a question of being able to start rolling forward when you start the car instead of backing out. When you get to the parking place, using the battery to back-in is a better use of the stored energy than using it 8 hours later when self-discharge has stolen it away.

You may want to try some 'snow tire traction tests' by starting with maximum cold pressure and then trying the handling and stopping at different, say 5 psi steps, down to the recommended. The DoT has a web site claiming that higher pressures improve handling and stopping distances at some loss of ride comfort.

I have had terrible luck with the JC Whitney, transaxle pan heaters. They barely last one season. I'm going to 'make my own' rather than try that mistake again.

I don't have enough information about it but given the excellent viscosity range and similarity to turbine transmission oil, I suspect it is synthetic. The main thing is to get worn-out, Type T-IV out of the transaxle and Type WS has significantly better low temperature viscosity characteristics. As for testing, I believe a hill rolling test is the gold standard.

Vehicle 'creep' is an illusion in the Prius because it is a software artifact created by the control laws to replicate a by-product of a screwed-up, automatic transmission design. The early automatic transmissions had this creep because they were not very well designed. The theory is 'people got used to it' but that is like saying, 'rear view vision is terrible because people got used to it' or 'accidents will cause death because people got used to it.' This is one of the nuttier things I don't like in the Prius ... the automatic creep followed by the abysmal rear view.

Bob Wilson