Cold weather mileage hit

Between the winter temperature drop and snow tires on my car, I've lost 10-15 mpg. It's a big hit, but still better than my Gen2 on its best day.

 

the bumps are already starting with protest marches in many major cities.

 

Yes, heard that on BBC radio news this a.m. I noticed Boston was mentioned so I'll be wearing my hoodie with Boston emblazoned across the chest for the next few days. Bought it one of the malls as a practical souvenir 7 years ago and it's survived really well!

 

I got my 4 touring in October. I started with a high of 56 mpg (daily) with a 90 mile commute up and down hills, with temps in the 50s or 60s. right now with stock tires, snow and temperatures in the high 20s to 30s I'm getting low 40s for mpg. Even going down the hill, the engine runs constantly for about 14 miles before my mileage starts increasing towards the 50s. It definitely feels sluggish in the cold weather. Looking forward to experiencing summer mileage results.

 

What's the PSI in those tires? Have you set them since the temps were much warmer?

 

Thanks for the report. Good information for those people who are considering buying a Prius, and live in cold-weather states.

 

Mine's gone down into very low 40's on drive to work, where it used to be about 70 in the summer. Problem is the coolant has to get to 104 before engine shuts off if HVAC is off. If heat is on temp has to get to 125 before it shuts off, then when coolant goes down again engine kicks back on. A day and a half of running errands Friday and yesterday I got about 58 because it was more highway so coolant got to higher temp so I could run heater w/o penalty. Scanguage or similar is a great way to figure out when to turn heat off if you are stuck in traffic. I watch coolant temp like a hawk when I'm city driving.

 

At least on 3rd gen there was some gradient to cabin temp vs engine shut off, ie: the engine would still shut off fairly readily if you were heating the cabin but with temp set kinda low. In certain mid warm up conditions I could turn the engine off and on by adjusting cabin temperature.

 

This would be my contribution to the wall of shame.

Worse 100 miles yet. Note temp and EV%. All miles were on a flat, dry highway under good conditions.

 

Wow! That's enough to freeze the balls on a brass monkey. No wonder you took a hit!

FWIW, when wooden warships had cannon guns, the balls were stacked as a small pyramid on a brass frame to stop them rolling around the deck as the ship swayed. This was called a "monkey". Hence the expression above, which had nothing to do with primate testicles.

 

Thanks.

After spending hundreds of wonderful hours reading novels from the likes of Alexander Kent, Dudley Pope and of course the genius Patrick O'Brian I am surprised I missed that one!

 

I noticed very similar mileage the other day when it was also 3 degrees outside. 1% EV driving ratio, 35 miles at 48 MPH average, 43 MPG.

Kind of cool to see the mileage with effectively no contribution from the electric motor. I take it to mean that the car would hypothetically achieve mid- to high-40s MPG on the highway in mild weather without the hybrid system

 

Possibly even higher mpg with no extra battery to charge for EV propulsion. It all takes energy!

 

and without the added battery weight.

 

I really miss having coolant and rpm gauges... Those 2 things are reason why I'm considering scangauge/ultragauge..

 

Have to ask why you need tachometer in a Prius? The engine revs have no relationship to the car's speed!

 

Yeah, considering the car is ecological centric, and supposedly a miracle of advance instrumentation: omission of a coolant gauge in particular is a MAJOR mis-step. I've had a ScanGuage hooked up soon after getting ours in 2010, coolant temp was one of the constant gauges I watched. I've since disconnected it, about a year back: there's a possiblity the weight of the scangauge cord was causing some intermittent fault.

 

Since we don't have one, I figure it would be interesting to see when engine is just idling, charging, or in fuel cutoff mode... I don't care how it relates to the car's speed... I'm just curious on how fast the engine is spinning in different situations (engine braking, just running for heat, etc).

 

You'll learn things like the other day when outside temp was low, coolant temp was pretty high but ICE stayed on. I also watch GPH and saw it was using no more than .2 GPH, which means it was not driving the wheels. EV light did not come on, but GPH goes way, way up when ICE is turning wheels.

 

While using the radar cruise control on my Prius 4, I am hearing more engine braking than using the motor/generator to slow down the vehicle at highway speeds. Not sure if it's cold weather related or there was a software update. Maybe when the temps fall below freezing, the ICE provides better braking than MG1/MG2?