Please post your winter G1 Prius tips here!

[Optimus]

Hello, I'm looking to collect tips for wintertime for the G1 Prius (or ones that are valid for newer generations). I would be looking for any aspect of tips ranging from winter traction, fuel economy, reliablity, safety, and more. I will be reporting on a set of Bridgestone Blizzak WS60 snow tires once I get them installed. I picked up a set of Honda steel wheels for my winter rims. Alloy wheels like to leak for no apparent reason around the beads in the winter time, so I tend to shy away from alloy wheels on any car.

I would be interested in people's experiences with tire pressures, synthetic oils (such as in the trans), and what I can expect when the car is completely cold sitting in a parking lot when it's -30F and windy to boot. This will be our first winter with a G1.

Post 'em up!

[tochatihu]

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

[john1701a]

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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[bwilson4web]

Originally Posted by Optimus

Hello, I'm looking to collect tips for wintertime for the G1 Prius (or ones that are valid for newer generations). I would be looking for any aspect of tips ranging from winter traction, fuel economy, reliablity, safety, and more. . . .

I would be interested in people's experiences with tire pressures, synthetic oils (such as in the trans), and what I can expect when the car is completely cold sitting in a parking lot when it's -30F and windy to boot. This will be our first winter with a G1.

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

[Optimus]

Thanks for all the responses. The main thing I want to do with this thread is mimic what they do in the main G2 forum, but more specific for us G1 owners, and to help anyone looking for such information. In a way, it's nice to know we don't have to worry about much. A co-worker has a good friend with a G2, and they said they must back into parking spots (so they can pull out forwards) because when it's this cold, the snow is blowing, etc.... the car does not have enough battery power in reverse to make it out of the parking spot. I'm sure they aren't referring to four foot snow drifts building around the car, but I'm sure they are speaking of something that takes a little more oomph to get out then what it would take on a hot summer day. Anyway....

I will probably run the snow tires at standard pressure for maximum traction, but it will depend on how well the car does I guess. It's pretty light, but it's not really much different in terms of weight then the car it replaced. Mileage went from a comfortable 50mpg in the summer (mostly highway) to 44mpg during a few days we had that were in the single digits (and snow tires are not on yet). As long as we can stay above 40mpg average, I'll be happy. With gas at $1.77 right now, I'm not too concerned about maximizing every possible variable, but I do want to know what the options are, if any.

I can install an oil pan heater, but I can see my significant other driving out of the garage with it still attached and dragging the garage down the road.... So, that might not be a good option.

We don't have much of a hill anywhere near us, so I don't expect to be able to try a rolling test, but we'll see what happens. Is type WS a synthetic or available as a synthetic? Reason I ask is, I can feel the different in "regular cars" and especially my 4x4's when I run regular 75W90 gear oil in the front/rear differientials and (manual) transmissions) and even with ATF in the autos. I don't use synthetic motor oil too much since engines warm up pretty quickly, but I do use it in the prius. Gear oil basically turns to mud when it's -30F, and automobiles are VERY sluggish until things warm up. It's even to the point where a (manual transmission car) in neutral will still creep forward in neutral, and when you suddenly inhale/exhale from the brief shock of movement, your nostrils freeze together for a brief moment. That's when you know it's cold.

[bwilson4web]

Hi,

Originally Posted by Optimus

. . . A co-worker has a good friend with a G2, and they said they must back into parking spots (so they can pull out forwards) because when it's this cold, the snow is blowing, etc....

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.

Originally Posted by Optimus

. . .

I will probably run the snow tires at standard pressure for maximum traction, but it will depend on how well the car does I guess.

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.

Originally Posted by Optimus

. . .

I can install an oil pan heater, but I can see my significant other driving out of the garage with it still attached and dragging the garage down the road.... So, that might not be a good option.

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.

Originally Posted by Optimus

We don't have much of a hill anywhere near us, so I don't expect to be able to try a rolling test, but we'll see what happens. . . .
Is type WS a synthetic or available as a synthetic?

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

[Optimus]

I haven't actually experienced any 'creep' yet with the Prius. I was merely commenting on the creep I've experienced with other vehicles. With "normal" auto transmissions at -30F below, I normally see a very delayed reaction time in shifting, be it the time it takes once you actually move the shift lever to when the trans actually engages into that gear (R, N, D, or P mainly) and even while shifting gears while driving (e.g. 1st to 2nd gear etc...). The prius is obviously a different beast and I am not sure what to expect (hence why I asked about synthetic vs. regular WS).

I actually think our G1 has great rear visibility. All the comments I've heard about bad visibility seem to be more about the G2. I've owned a lot of cars, and I'd go so far as to say the G1 Prius is one of the best visibilities with the tall windows and what-not.

It just seems so counter-intuitive that higher tire pressures equal better handling and stopping distances, unless they are not referring to snow tires specifically. Normally, "airing down" for a wider foot print with more surface area in contact with the road has been better for traction in terms of snow, off-road (obviously not with a Prius), rock crawling (again, not Prius style), etc... not to mention the ability of the tread/sidewall to flex better to better conform to the shape of the road. That being said, airing down is harder on mpg as we all know, heats a tire up, and causes overall squishy handling. Without reading the article yet, maybe that's what they meant.