The Prius In Winter
By Bill Moore
25 December 1999 -- For the last year or so, I've suggested, somewhat with tongue-in-check, that a car maker let me subject one of their vehicles to the rigors of a Nebraska winter where it can be 60 degrees F one day and 12 degrees F the next. They would chuckle and change the topic.
Then Toyota decided to take me up on my challenge. Though it took until mid-December for winter to finally arrive on the American Great Plains, it did and with a vengeance, giving me the opportunity to see how a gasoline-electric hybrid would perform in climates other than balmy California and sunny Arizona.
I am pleased to report that other than two minor annoyances, the Prius, performs admirably on ice, snow and in temperatures that have ranged down to -12 degrees Celsius, or in the single digits Fahrenheit.
Winter 1999 has taken an unusually long time to set in here in Omaha. We can usually expect freezing temperatures in October and snow by November. This year, we've been blessed with the longest stretch of mild weather I can remember, possibly one of the few benefits of global warming.
For our readers who've never visited Nebraska - and I suspect that's most of you - it is situated in the middle of the North American continent, halfway between the Gulf of Mexico and the Canadian border. To the West rise the Rocky Mountains which function like a granite wall, channeling frigid Arctic winds down from Canada and Alaska. Temperatures have been know to drop as much as 40 degrees in twelve hours time. In fact, the winds blow so steadily through this region, that it is fast becoming the center for wind farm development, replacing California. This bodes well for completely zero-emission EVs someday in this part of the country.
With the exception of a table-flat region in the center of the state south of the Platte River, Nebraska is a rolling landscape that once teemed with millions of bison and an ocean of prairie grass. Today the eastern half of the state has been turned under the plow to grow corn (maize), soybeans, and similar row crops. The western half of the state is pretty much cattle country and sparsely populated. Media magnate, Ted Turner, owns tens of thousands acres of Nebraska Sand Hill's cattle country on which he runs a small herd of bison.
Here in the Midwest, we experience the extremes of weather from tar-melting summer heat waves to prolonged spells of bitterly cold temperatures which hover just at or below zero Fahrenheit. It is not a climate conducive to the faint of heart or electric vehicles.
Facing Winter's Worst
Two weeks ago, we woke up to ice-coated roads and a couple of inches of snow, helping to alleviate one of the longest dry spells on record. The night before, forecasters weren't expecting the snow to reach this far East in the State. Obviously, they were wrong. I had a early morning conference to attend, so I decided it was time to see how the Prius would fair, though I was a little concerned about the slick conditions. The last thing I wanted to do was "dent" Toyota's car. But I also figured, it was now or never. If hybrids like the Prius and Insight are going to be accepted by the public as substitutes for their conventional ICE vehicles, they are going to have to prove they can operate in these conditions. So, I threw my EV World carrying bag onto the passenger seat and backed out of the garage. The outside temperature on the Prius' display screen was just above freezing, though it quickly dropped to below freezing after traveling a few blocks.
My concerns about the performance of the car on ice quickly thawed at the first stop sign, just around the corner from my house. It is an uphill grade and previous traffic had polished it to a glittering glaze. I pulled up to a stop behind another car, keeping a safe distance. This meant I'd have to climb the ice-coated hill, come to a stop and accelerate from a dead stop just below the crest of the hill. The Prius handled it with aplomb. The wheels didn't even spin. This isn't to say the Prius is a substitute for a good 4 wheel-drive - even they have problems on ice - but in light snow or ice, it will get you around as long as you exercise the same level of caution you normally would with any front-wheel drive vehicle.
As you might expect after the first snow and ice storm of the season, traffic was at a crawl, perfect conditions for the Prius it turns out. Driving the five miles from my home to the conference, I got some of the best gas mileage I have gotten so far. In the ten minutes or so it took to get to my meeting, the car got nearly 30 km/liter or the equivalent of close to 65 miles per gallon!
Seeing The Turtle In Winter
As we drew closer to Christmas - and it will be a white one this year - the temperature has steadily dropped and two nights this week the thermometer plunged below zero F. Since I have a two car garage, the Prius enjoyed the benefit of being out of the weather in temperatures just above freezing.
During the day, however, it nobly sat outside our offices from 7 am to 5 pm in single digit temperatures, starting without fault when it was time to drive back home in the fading light of dusk. The prolonged exposure to single-digit temperatures did, however, have an affect on the car's nickel metal hydride batteries or at least, that's what the Prius' instrumentation seemed to indicate. For the first time since driving the Prius, I saw the "Turtle."
This is an instrument panel warning icon which resembles a turtle and appears when the battery pack has dropped below its normal State-of-Charge (SOC) operating range. Presumably this occurs when heavy demands have been made on the pack, typically on prolonged, high-speed road trips. When I drove the car to Kansas City back in September, the "turtle" never once appeared despite driving at speeds of 75+ mph for nearly three hours.
Concerned about how the car might perform on the drive back home, I was tempted to take a less demanding route through town. Instead, I figured it was important I find out just what impact the "turtle" might have on the car's performance on the freeway. Merging with the fast-moving traffic, the car accelerated nimbly, drawing the usual amount of power from the battery pack, which indicated it was at full SOC. For the next ten minutes, I kept an eye on the instrument panel and the Prius' video panel display. The car showed no degradation in performance, whatsoever, and within a mile of home, the "turtle" light went out, indicating all was well again with the batteries.
The next day, I repeated the impromptu experiment and again, the Prius performed as expected. The only other minor annoyance I uncovered during our spell of Winter weather the week before Christmas, was a "popping" sound either in the steering or front suspension, I haven't figured out which quite yet. It doesn't affect handling, but it does need to be corrected before the car goes into service in colder climes. Whatever it is, it is definitely caused by below freezing weather. Thankfully, it is expected to warm up again next week, getting into the 50's the day after Christmas.
As you might expect, the severe cold has reduced the car's mileage somewhat. On my commutes to and from work during warmer weather, I would typically get one or two five minute segments in the 20+ km/liter range or about 48 mpg. Now I am seeing segments just below this range. I refueled the car yesterday at 22,848 km or 587 km (364 miles) since my last fill up. I topped off the tank with 10.5 US gallons of unleaded gasoline, so my miles per gallon works out to be 34.6.
Worth The Cost?
Given these real world, Winter performance numbers, I've heard more than one observer comment that there are conventional cars that perform equally or better in terms of gasoline efficiency. I am not convinced that happens to be true, but even if there are a few models on the road which can get mpg's in the mid to high 30's in Winter driving conditions, they are in a definite minority and are probably sub-compacts using diesel engines which presents its own environmental concerns.
For critics who see these numbers as an argument against hybrids, I would point out that the Prius is, after all a first generation vehicle engineered originally for the more temperate climes of Japan, not the wide-open hinterlands of the vast American Great Plains. Even in these hostile conditions, the Prius turns in commendable performance which is pretty much unmatched in a vehicle with the interior room and refinement you'll find in this car.
My final observation is that the future of advanced vehicle technology rests, to a large measure, on the success of cars like the Prius and the Honda Insight. Bought in sufficient numbers, they can help drive down the costs of electric drive technology. But it will take customers who are more than just "sunshine patriots" in this energy revolution. They must put their convictions to the test and sign their names on finance contract to prove to the doubters in the auto industry that there is a market for this 21st century technology from the equator to the poles.
blog comments powered by Disqus