[Flatland 306]

I just got my 25 AE Feb 27 and I live in Saskatoon, Canada. Winter here is -10c to -40c (14f to -40f). I don’t have any experience with summer fuel efficiency but maybe some members that do get cold temps can weigh in on the difference they get from summer to winter. So far on the divided highway (interstate) with a strong 60kmh tail wind I was getting 7.7l/100 at 119kmh at -10c.
We did a trip around the city yesterday with several stops and 30 or so Km on the highway going 109 or 99kmh. It averaged 9 ish for the day. It was -14 to -18 with a wind. Not great but likely 5 l/100km better than my ‘08 highlander v6.

I’m interested in the hybrid logic and how to control it a bit. What I’ve learned so far is that when the heat in the cabin is set to auto and temp to “Hi” the van will use the engine exclusively. It seems to make the engine work as hard as possible so it will produce as much heat as possible into coolant to give to the cabin. During this scenario it steadily charges the battery up to one bar from full. If on the highway going 109kmh it will start to use some battery but once you slow down to, in my case 60kmh, it will charge the battery again. Once I changed temp to 24c it started using the battery again.

Another theory I have is it will only charge the battery when it’s cold. It won’t use battery power until it’s warmed up. We park in our 5c garage and it seems to function normally from there. We parked outside in -16 for a couple hours so the battery got cold and it charged the battery to one bar from full then it stayed there for a while after the cabin got warm. So I wonder if it charges full then uses excess electricity to heat the battery to a certain temp before it starts draining?

Has anyone had luck controlling battery use with drive modes or some other trick?

 

[elementZ]

Don't set the HVAC to high. Set it to the temp you want the cabin to be, and let the computer sort out what to do to reach the setpoints. Also use a block heater if it's possible.

 

[20swrt]

Cold weather tip #1 - use seat warmer instead of central air/heat. #2 - dedicate engine heat to windshield blower (front / windsheild defroster) only. #3 tire pressure no less than 37 psi - COLD ! #4 no need to warm up vehicle more than 3 mins before driving slowly (less than 5 mph for the next 1 or so miles) - aka rolling warm-up. #5 dress warm (make sure not to block vents underneath driver/passenger seats). The Sienna uses Ni-MH batteries so it really does not need to be warmed up for the HV battery to start charging. #6 in stop-go traffic. if the ICE still runs even if traffic is not moving (engine fully warmed up)...it might be because it is trying to heat the cabin....turn off cabin heat (i know it sucks - thats why dress warm #5). #7 If you do not have any rear passengers - make sure you dont turn on heat or a/c in the back seats.

 

[Sienna9816]

If you have a 1500W outlet, consider a space heater with proper precautions.

 

[pamhar]

We also park in garage most of time and do not warm other then time it takes me to click on that warning on 9" screen.

Then back out of garage onto driveway. Take 10 seconds to unfold side mirrors and drive moderately. Nearest highway is about 15 minutes away so get to warm up van although many people here drive at highway speeds on city roads!!

Our winter temps are probably in -5C to -25C range without wind chill.

Last several tanks we got 6.02, 6.69, 7.05 [CPU was 2-5% better] for Dec, Jan, Feb. That 7.05 tank included some idling as waiting for someone. Normal for winter is more around mid to high 6s.

Keep in Normal mode and while heat is on Auto the fan is on 2 bars and not overly high temp setting which greatly helps. PSI is set at 35 in garage so more like 37-38 in cold outside. Lowest that have seen once pressures are available is 34.

 

[Flatland 306]

Pamhar, I’m not sure I could get it down to that level. You must have the hybrid driving dialed in. Today I was very careful to try to get it as low as I could and only got to 8.4l/100km.

I’d shut the heat completely off, fan and everything and only turn it on once the engine started due to acceleration or high speed. I’d only accelerate in the green eco band. Ran the heated seat on low. It was -15 or so today.

Did yours get better after break in?

 

[cougarhound]

I don't think there is much you can do. In those extreme temps most evs prob lose half the range. The chemical reactions in the batteries slow down. Even those lithium jumpers don't work. Try taking the crossbars off the roof rack.

 

[Richard E]

I am getting around 7.4 l/100k on hilly rural driving with a pretty full load In winter in Ontario. Summer tanks are closer to 6.2- 6.4 l/100k.

There is definitely a break-in period. My auto electronics specialist brother-in-law says it is programmed into the engine computer, and at some point you will see a sudden jump in efficiency.

 

[Chubbysumo]

I am getting around 7.4 l/100k on hilly rural driving with a pretty full load In winter in Ontario. Summer tanks are closer to 6.2- 6.4 l/100k.

There is definitely a break-in period. My auto electronics specialist brother-in-law says it is programmed into the engine computer, and at some point you will see a sudden jump in efficiency.

there is no break in period with these, none. I was getting 38mpg or better from the start(in summer, without the trailer).

 

[pamhar]

Pamhar, I’m not sure I could get it down to that level. You must have the hybrid driving dialed in. Today I was very careful to try to get it as low as I could and only got to 8.4l/100km.

I’d shut the heat completely off, fan and everything and only turn it on once the engine started due to acceleration or high speed. I’d only accelerate in the green eco band. Ran the heated seat on low. It was -15 or so today.

Did yours get better after break in?

Mileage has been in same range since bought.

Have only used heated seats maybe 6 times so far and heated steering wheel maybe 2-3 times... that not help mileage if use regularly.

You've checked PSI levels? Speeds above 110 or 120 also hamper mileage.

You're also in colder temps so it's not you... it's the weather

Update us when temps above 5C.

 

[Richard E]

there is no break in period with these, none. I was getting 38mpg or better from the start(in summer, without the trailer).

I definitely noticed a difference- I bought mine in winter and was lucky to get 8L/100km a tank. Now that would be lousy mileage even for winter. I think I saw a dramatic jump in the spring, but also changed tires and it warmed up.

I think driving style makes a big difference with the hybrid. If you are heavy on the gas it’s a bit of a pig, but if you optimize EV driving it’s good,

 

[slk]

We’ve experienced the same L/100 KM numbers this winter on our 23 XLE. We head to Florida in 3 weeks so I will swap out the snow tires before we leave and see how that and the increased temps change things. Then we will soon switch back to the summer blend of gasoline which should give us a boost again. Last year we saw 36 MPG or 6.45l/100km.