Cold Weather Fuel Economy

Re: What am I doing wrong?

Tell us about how you use your Prius. Short trips are mileage killers. For example, in last night's cold (19°F), with a warm engine, I was getting 38 mpg after filling up. The 38 mpg was from several short trips in the city, with stops for shopping between each trip.

Because of icy roads we could only drive 45 mph on the trip home, which is about 30 miles of two lane state highway (55 mph limit). I pulled into the driveway showing 45 mpg, so I was averaging close to 50 mpg on the way home. The only difference between the 38 and 50 was the type of driving.

Tom

 

LISALISA - for me to get 100 miles before the 1st pip disappears calls for a celebration!

there's no way that i'm resorting to hypermiling, but i will try to drive as conservatively as i can. there are people here that can get insane mileage, but they're probably moving road blocks.

i'm happy getting 45 mpg with performance tires and that's really as slow as i can drive.

 

Hi LisaLisa,

I am about 3/4's the way through this tank, and drove this week where the drive into work was 3 F on the Prius temp gauge, and then 10 F on the drive home. The next day was about 8 F in the morning and 20 in the evening. I was in the mid 56's mpg until the cold weather hit this week, after filling up midweek the week before. I finished the week at 53.5 mpg. I was too lazy to hook up the block heater for various short-of-sleep reasons. This was with BP gasoline this time round. I usually get Shell, which is good for a few mpg better, I guess. Mobil seems to be the lowest mileage gas around here. When the temp is above 15 F I rarely use the heater, and just for defrosting, or if its snowing to keep the windshield warm. I do dress warmly. I have the heater set for 65, and would use it more if it had something like a 50 F setting, but it only goes down to 65 F. If your not into keeping the 70 % of the heat loss out of your body covered up (ie wearing a proper winter hat and mittens below 10F, not gloves) your going to have some issues with getting good winter mileage. I did have to scrape the inside of the hatch window to get rid of the ice build-up twice this week.

This tank dropped the first pip at about 60 miles, but a 70 mpg summer tank will not drop the first pip until after 200 miles.

One of the things I discovered the summer before last that got the summer mileage over a plateau I was at (63 mpg best) to getting consistent 68 mpg summer tanks with the best at 70 mpg is the early part of the route. It has to have a minimum stoping time. If you get on a main secondary road that feeds to the interstate, and you run the car for 5 minutes to sit and wait 5 minutes, then a small distance, and sit for 3 minutes, then another small distance and another 3 minute wait, and then get on the interstate, the first 5 miles of interstate will have terrible mileage because the car is running at a lower mileage condition while the engine rewarms up, and the battery has to recharge from the slow and go at the lights. And that will kill your averages. I changed one direction of my commute to a route with short lights, and many times they are green when I get to them. The other commute direction has always been 5 miles before the first long stop at 25 then 35 mph. The early portion of one's drives is just one of the many things however. The Prius warm-up cycle is very bizarre and inconsistent, changing what it does with only very slight differences in conditions. It was not until I had instrumentation that I realized this. And only after driving the car with the instrumentation for a year till I realised what I had to do to get better results.

When I do the around-town errands I rarely match the average I have built up over the week.