Still considering a Prius but have a Q for you all.

My new job (yeah!!) is now local so I'll be commuting into work daily.

The drive is about 6 miles regardless if I take the highway or secondary roads. My concern is in really cold temps like we have here today, will I really benefit from the battery power at all on the way into work?

On the way home I have about an 11 mile trip on secondary roads as I have to pick up the kids at school, so the car will have a chance to warm up then, but what can I expect in the mornings mpg wise?

Most speeds on the secondary roads are 35-45mph. Freeway I tend to go 70-75mph. I won't likely vary my habits/speeds in a prius if that matters in considering mpgs. I'd rather trade the handful of mpgs vs being a rolling road block in fast moving traffic.

Thanks!

Five Passenger/All Season V8 Powered Fun

Hello, Tim!

It's not so much that the Prius "benefits from battery power" during sustained driving. The Prius infrequently moves under battery power alone, regardless of trip length. A major benefit of the Prius' hybrid system is a small (1.5L) ICE (internal combustion engine) that runs efficiently at a variety of speeds, despite a car of almost 3000 lbs. Now, if that ICE was the only source of propulsion, then the car would be woefully underpowered. So the electric motor provides immediate and significant low-end torque for short bursts of acceleration when needed.

In addition, after a short warmup period, the Prius shuts the ICE down completely when not needed for propulsion -- coasting, braking, or idling. The warmup period, as you might guess, is lengthened in cold weather, and the ICE will run to keep itself warm. Running the cabin heat will lengthen the warmup even more and draw heat, causing the ICE to light even if not needed for propulsion. All of this costs fuel economy.

Short trips hurt MPG in all cars. The effect is probably magnified in the Prius because of this warmup period. For the first five minutes of driving with a cold ICE, results of 20-30 MPG are not uncommon, even in warm weather. 40-50 MPG for the next five minutes can be expected in typical conditions, though it will be lower if the heat is constantly run in cold weather at slow speeds. At highway speeds where the ICE runs continuously anyway, cabin heat has less effect.

Many of us have taken some simple and inexpensive steps to improve fuel economy in cold weather -- namely, an engine block heater and blocking the front grill. You might search here and on PriusChat for more info on either of these if you want it. With those modifications, my first five minute MPG reading is usually at least 40, and can approach or even exceed 50 in warmer weather.

Good luck, and I hope that helps!

Jim

Lifetime fuel mileage:

After learning how to hypermile:

Hi,
In the winter for 6 miles, I would expect to see 35 MPG. It gets much better once the temperatures reach 50F and above. You can get some help by using a block heater.

One of the things Prius drivers learn is how to use other, slow traffic to provide 'cover' for our optimum speeds. This means looking for the slow vehicles and following them at a safe distance. There is not need to be at the head of the line of slow vehicles, just be another member of the 'train'.

Recently I drove through the Atlanta freeways and had no problems by simply following slower traffic. I did see one slow car in the right most lane get 'flashed' by an Atlanta driver. Yet following a semi-trailer truck at a safe distance gave me immunity from the 'flashers.'

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
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