Observed cold weather MPG difference

before my plug in, i used to see a 10 mpg difference from spring and fall to coldest winter. 65-55 on the mfd.

 

My warmest tank is 46 MPG, my coldest is 35 MPG.

 

I'm planning to install a engine block heater, hoping it will help without costing more in elect than it saves in gas. My last tank was off by roughly 3MPG and I expect it to be worse come freezing temps.

Be sure you adjust those tires as the pressure drops in the cold.

 

Here is a graph showing the seasonal MPG for the first two years of my Liftback. Your 'v' would have a different scale, but the relative change should be similar.

 

Over last nine years and having had a Gen II and a "v" have always seen a decrease in mileage averaging around 4-5 mpg difference. I've put this condition due to several factors, the cold makes increased demands on the batteries, which have a harder time keeping charged and causes the engine to stay on longer. The other factor hear is the difference between summer and winter fuel the distributors/oil facilities turn out. While I do not have specifics of what the do I just know they do adjust the gasoline, which seems to produce less mpg in colder months. One contributed recommended using pipe foam insulation and applying to lower grill area. I did this last year and it did seem to help keep the mpg average more constant, I. E., mpg stayed around 48 (for me), although I removed this insulation when temps returned to mid-50s. There are some other excellent background contributions in this forum by folks who seem to be experts, might be worth searching.

 

Each of these "cold weather" threads reintroduces the same problem, we don't know anyone's idea of what "cold" actually represents. So, always keep LOCATION in mind when reading comments.

For me, cold is well below freezing. Seeing temperatures with 20's as the high is quite normal... here in Minnesota.

This graph from my regular Prius gives a general idea how the V model would react in the same conditions:



The drop due to the seasonal changes is quite obvious. But even so, the hybrid system still outperforms the efficiency of traditional vehicles.

 

Here's my Fuelly graph for the past year:



(Edit: we have relatively mild, coastal winters. Also, I switch from 215/45R17 Michelin Pilot to 195/65R15 Michelin X-Ice2 every fall. The latter seems to break even.)

 

There is long list of reasons cold is worse but one thing is change in gasoline formula to winter mode. Some factors like that kick in even if there are not other obvious weather changes.

 

I've seen a small drop in mine on the last week or so here in Ireland with temps down to freezing at the weekend. That was my que to fit my 15" Goodyear Ultragrips (winters), which I did today as well as getting alignment done. We will see how it goes now with the new tyres fitted.

I also noticed that the dealer overfilled the oil too, so will be getting a fresh oil change in the next few weeks.

Volume wise, what is the recommended oil quantity for an 08 gen 2 again?

 

I've recently filled up and 36 mpg +- is the worst so far. Several things conspired to make this tank worse. I did the dealer service, put on my Artic Max snow tires, the temperature dropped from the 50's into single digits and teens, and the Wind. IMO, the wind is a monster factor. 30+ mph winds I could feel the car struggling. This past week on the new tank, the temps are 14 to 25 degrees, and the winds have stayed firm, gusting to 40+ mph. Now my computer reads 34 mpg.

Interesting to note that our 2007 Camry hybrid suffers little from the winter months, averaging only 2-3 mpg less maximum, mostly due to idling at warmup. In fact, the Camry Hybrid gets better mileage (so far) than my new V does.

I think the biggest deficiency in the V is that it's underpowered, forcing more throttle than would be necessary otherwise.

It will be interesting to see what happens this winter, since I bought it new in May. My average was a pretty consistent 42 mpg, not bad considering the highway driving I do, which is uphill in many areas.

 

My most recent tank was off by 7-8 MPG over warm weather. I have yet to install the block heater. But I have a hunch it has as much to do with cold tires as anything else.

 

It's been abnormally cold for November in Oregon and I do a lot of short trips. So I kind of think I have close to a worst case scenario going.

I've had about a 10mpg drop. from 50's to 40's.....but I expected this, and I think you still have to be deliriously happy with a vehicle that is getting upwards of 40 mpg, in winter.

 

I am still getting 50mpg across the river in Vancouver Wa.

 

Same here, too many short trips so it doesn't always get fully warmed up. I'm hoping the block heater will help change that.

 

The short trips are a killer in all cars, not just hybrids. The constant stop and go hits the engine at it's worst possible spot.

My current tank is now back at around 37.5. Doing longer trips helps.

The weird thing is that my 2004 Corolla, my 2011 Camry, 2007 Camry Hybrid, all other cars did just fine in the winter. The only time I noticed any appreciable drop is when I intentionally idled and warmed the car up. I hate the cold, and hate cold cars.

Our Camry hybrid is the same, mileage only drops when warmed up excessively. Other than that, it's around 38 now as always.

 

Short trips are MPG killers in all cars because you are using energy for warming up car and cabin, not becasue of ill timed engine start/stops. On short tips you spend energy warming up stuff and then when the car starts most economical warmed up driving you are stopping and you see worse/worst MPG.

Camery Hybrid has a bigger ICE engine than any Prius. If you are used to those (combine) 200 HP, the Prius v (wagon) will seem underpowered. Try the Power mode for a more Camery-like ride, but a less Prius-like MPG.

I could not tell what needed the most breaking in, my brain and hypermiling driving skills or my Prius v itself. It took 6 months before it all came together for me and my v and we are now averaging very close to the EPA 42 MPG over the 2 years with my Prius v. That is with a good mix of hypermiling and tearing up the roadway when I feel/need to. Those first 6 months were fustrating as I was struggling to get 38 MPG.

Just enjoy your new roomy ride (in Power mode if that is what it takes) and keep developing your hypermiling skills as traffic permits.

 

For the last three year winters of driving in the Washington DC Metro Area , my 2010 Prius MPG has dropped each winter and risen each summer and dropped when I have taken +600 mile (each way) +65 mph interstate highway road trips(around March-May). I've employed a variety of hypermiling tricks to extend my Prius's fuel efficiency so this fuel efficiency chart closely represents the best that I probably could have arrive at.


http://www.cleanmpg.com/garage/images/cha3707.png


The above chart demonstrates:
1) +60 mph lower MPG and
2) cold temperatures lower MPG.
3) MPG is from 71 to 44 mpg - 27 mpg range with an average of 60 mpg
which represents a +18% bump(+11 mpg gain) or
a -27% drop (-16 mpg loss). That is to say - it is easier to drive a Prius
into the ground with less fuel efficiency than it is to drive a Prius more fuel efficiently.

Conversely (in other words)...
1) lower speeds (e.g. 35 mph) raises MPG and
2) warm temperatures raise MPG.
3) while hypermiling isn't all that useful at speeds greater than 60 Mph ,
the Prius can still achive 44 mpg which is still competitive when compared to
conventional gas powered vehicles and to a diesel engine vehicles.



If I ignore the annual road trip data (and times I had to shuttle people around) then 2011 and 2012 look very similar and that the fall-winter of 2010 and 2013 are very similar. That is to say it looks like the Washington DC Metro Area is going have a very cold winter

 

I don't hypermile at all and 42 was fairly easy. As for temperature, 25 and up it seems happy. Below that it gets cold and grumpy, like I do

On this tank I'm back up to 40, and that's with the heat on, snow tires on, etc...

I've played with the power button on and off, and it's far more drivable with power on. Just have to watch the foot because the pedal has zero pressure on it in that setting.