Most of my trips are long, however in the winter so far I have noticed a .9 MPG decrease. Not much. Like Mel indicated my driving habits will affect the milage more.

 

Thanks all

 

Yeah, I'm averaging about 17 MPG in the winter compared with 21 in the summer. My ICE almost never shuts off. I have noticed though, if you drive for about 10-15 minutes, let the car sit (turned off) for a bit, and then get in again, the truck will often go into EV mode.

I think I read here that it's because the 300v batteries need to get up to temp as well as the ICE to get to the EV mode.

I saw you post this before. I was under the impression that the heat works just as a normal (ICE only) car. Where the water temp needs to rise for heat. I don't think we have electric coils to provide the heat, well besides in the seats!

I know the A/C in the Hybrid is different, where the compressor runs off of the electric batteries rather then a belt driven system.

 

I'm not claiming to know how the system works completely. It just doesn't depend on a heater core being warm from hot coolant to provide all of the cabin heat. We had temps in the teens here a week or so ago. The truck was outside at the movies, I hit the remote start from 100 yards away and when we arrived at the vehicle, the cabin was heating up and the ICE wasn't even running, and didn't until I put the key in and turn it to run. Again, I am not trying to mislead anyone, I just like the way it heats/cools quickly and the fact that the engine even heats up fairly fast. Maybe one of our more knowledgeable guys can chime in on why this system seems to be so much better comfort wise than a conventional ICE/heater core combo.

 

The cold is kicking my butt. During Christmas break from work all I did was short trip shuttling of children in 4 HI. I used remote start and set a new record low for 2 Mode winter mpg. I was down to 17.6 mpg average. Outside temp was single digits F.

Last few days it is just above freezing. Spent all day today on highway (70 mph) and 2 lane country roads. Shopping for new car.

Back up to 19.5mpg

 

Last winter, I found that the real cold weather (freezing to -20C (-4F) ) took the mileage down about 2 mpg.

This winter, with 43,000K on the vehicle, I am getting about 1 mpg better (19 vs 18 last year). I think this improvement also has to do with the recall reprogramming - I find it stays in V4 longer and I am surprised to look down when I am doing just under 30mph and it's on autostop.

 

I have found in cold weather the ICE always starts, because of the cold temp and the baby I always let the truck warm up on remote start. Heating has not been a problem. I do not often complete short trips so I cannot comment here. My Tahoe Hybrid is more of a long range mission vehicle.

 

Since I live about 60 miles from the metroplex and 10 to 15 from the nearest destinations, my mileage is varied. Sometimes I spend a day in metropolitan conditions and whether I am on the highway or intown, I seem to see basically the same mpg's. The highway at 70+mph however is slightly less mpg's than is the intown stuff. But the cold only seems to put a less than 2mpg hit on me. I will say this too, it does not have to be very cold to do that. Less than say 50 degrees F outside and the ICE runs more and starts more frequently. I see the mpg drop when the temps are below 50. This is the same with the Prius. Guys block the grill on it when the temps are consistently below 50-60F. But in north Texas, the temperature variation is unpredictable. I would think some of you Canadian guys could benefit by rigging a grill block of some sort. You do need to monitor the coolant temps. On the Prius, guys use a Scan Gauge II and it plugs in right below and right of the steering column. I mounted mine in a small compartment and just pulled the cord through an opening in the back of the compartment for a clean permanent install look. I have sense stopped using it and don't block the grill much anymore because the wife has the car.

 

I thought I had saved all the articles I have read on the 2modes...I can't seem to find the information on climate control that I have read previously. I was hoping Marty or fjungman had the inside scoop. As t-pole mentioned, yes the a/c is a 300v electric compressor and runs when the ICE is off. As I recall, and that can be dangerous to rely on...so does the heater. I know it heats the cabin when the ICE is not running but don't know if it is just a supplimental or the way the entire system works. I will keep looking for the information as I am sure we all would like to know what we have here!

 

The heating system is standard; runs off of engine coolant heat. Plenty of latent heat there during the short periods when the engine is off. Since you're not going to get autostop for a while during the periods when you really need heat, the system is going to be good and warmed up when autostops do happen. So no need to design in the extra complexity of separate smaller cabin heating loop with an aux electric heater.