Difference in Summer to Winter operation
12-04-09 | 12:48 PM
#1
Thread Starter
Pole Position
Joined: May 2009
Posts: 2,838
Likes: 23
From: GA
Difference in Summer to Winter operation
Hi folks,
I have a very early (may build) RX450h and no problems whatsoever to complain about but I do have a question re: traction batteries and ICE with your 400h models.
Since you folks have had a chance to notice seasonal changes (if any) I've noticed on mine that the time after starting up in cold weather to the ICE starting is much less than when the batteries were warmer. Is it the same for you? Also it seems that on the colder days it takes a lot less throttle response to go from batteries only to combination power. But mileage doesn't seem to have suffered from anything other than my occasionaly heavy foot to enjoy the mindbending power
.
Thanks in advance
I have a very early (may build) RX450h and no problems whatsoever to complain about but I do have a question re: traction batteries and ICE with your 400h models.
Since you folks have had a chance to notice seasonal changes (if any) I've noticed on mine that the time after starting up in cold weather to the ICE starting is much less than when the batteries were warmer. Is it the same for you? Also it seems that on the colder days it takes a lot less throttle response to go from batteries only to combination power. But mileage doesn't seem to have suffered from anything other than my occasionaly heavy foot to enjoy the mindbending power
.Thanks in advance
12-05-09 | 02:14 PM
#2
Pole Position
Joined: Feb 2002
Posts: 385
Likes: 1
From: CA
Yeah I've noticed a difference. From the time I turn the ignition on the ICE comes on shortly and the ICE would idle until the engine reached normal operating temperature. With that being said if I switch off the cabin heat the ICE would shut off and car would drive as normal. The gas mileage went from 26mpg to around 25mpg as the gas engine idles more often such as warming up in the driveway.
12-05-09 | 02:46 PM
#3
Driver
Joined: Nov 2006
Posts: 162
Likes: 1
From: ny
You will notice...
Mileage will suffer... bottom line... the cold, is the cause...
A. The catalytic converter is designed to operate at a particular temperature range, therefore in order for the catalytic to run effeciently, the engine will run to maintain the required heat in the catalytic converter.
B. If you operate your ventilation system to heat, the engine will need to operate to get the antifreeze coolant hot, allowing for the heatcore to dissipate heat into the passenger cabin.
C. batteries when cold are much less efficient at doing what it is they do, they are designed to do... charge, discharge, charge, discharge... therefore because of the cold, they require more energy to do the same amount of work and are therefore less efficient.
D. The general electrical load placed on the vehicle during the winter period is greater. Rear Defroster / Mirrors, Wiper Function / Wiper Fluid, Fog Lights / Driving Lights, Heater (as mentioned above) / Seat Heater.
E. Slippage (driving surface cold, slippery) and Resistance (things run with more resistance and friction when cold) add to the overall lack of efficiency.
I usually go from a gentle 32mpg in the summer (and if I am really carefull, I can easily get 34-35mpg) to about 23mpg (temperature range of -5F to -25F ) in the winter (still being carefull, but not as gingerly as I am in the summer months) period.
Cheers,
MadloR
P.S. I will pm you... so, you know Jim Myers :P
A. The catalytic converter is designed to operate at a particular temperature range, therefore in order for the catalytic to run effeciently, the engine will run to maintain the required heat in the catalytic converter.
B. If you operate your ventilation system to heat, the engine will need to operate to get the antifreeze coolant hot, allowing for the heatcore to dissipate heat into the passenger cabin.
C. batteries when cold are much less efficient at doing what it is they do, they are designed to do... charge, discharge, charge, discharge... therefore because of the cold, they require more energy to do the same amount of work and are therefore less efficient.
D. The general electrical load placed on the vehicle during the winter period is greater. Rear Defroster / Mirrors, Wiper Function / Wiper Fluid, Fog Lights / Driving Lights, Heater (as mentioned above) / Seat Heater.
E. Slippage (driving surface cold, slippery) and Resistance (things run with more resistance and friction when cold) add to the overall lack of efficiency.
I usually go from a gentle 32mpg in the summer (and if I am really carefull, I can easily get 34-35mpg) to about 23mpg (temperature range of -5F to -25F ) in the winter (still being carefull, but not as gingerly as I am in the summer months) period.
Cheers,
MadloR
P.S. I will pm you... so, you know Jim Myers :P
12-05-09 | 03:12 PM
#4
Thread Starter
Pole Position
Joined: May 2009
Posts: 2,838
Likes: 23
From: GA
Mileage will suffer... bottom line... the cold, is the cause...
A. The catalytic converter is designed to operate at a particular temperature range, therefore in order for the catalytic to run effeciently, the engine will run to maintain the required heat in the catalytic converter.
B. If you operate your ventilation system to heat, the engine will need to operate to get the antifreeze coolant hot, allowing for the heatcore to dissipate heat into the passenger cabin.
C. batteries when cold are much less efficient at doing what it is they do, they are designed to do... charge, discharge, charge, discharge... therefore because of the cold, they require more energy to do the same amount of work and are therefore less efficient.
D. The general electrical load placed on the vehicle during the winter period is greater. Rear Defroster / Mirrors, Wiper Function / Wiper Fluid, Fog Lights / Driving Lights, Heater (as mentioned above) / Seat Heater.
E. Slippage (driving surface cold, slippery) and Resistance (things run with more resistance and friction when cold) add to the overall lack of efficiency.
I usually go from a gentle 32mpg in the summer (and if I am really carefull, I can easily get 34-35mpg) to about 23mpg (temperature range of -5F to -25F ) in the winter (still being carefull, but not as gingerly as I am in the summer months) period.
Cheers,
MadloR
P.S. I will pm you... so, you know Jim Myers :P
A. The catalytic converter is designed to operate at a particular temperature range, therefore in order for the catalytic to run effeciently, the engine will run to maintain the required heat in the catalytic converter.
B. If you operate your ventilation system to heat, the engine will need to operate to get the antifreeze coolant hot, allowing for the heatcore to dissipate heat into the passenger cabin.
C. batteries when cold are much less efficient at doing what it is they do, they are designed to do... charge, discharge, charge, discharge... therefore because of the cold, they require more energy to do the same amount of work and are therefore less efficient.
D. The general electrical load placed on the vehicle during the winter period is greater. Rear Defroster / Mirrors, Wiper Function / Wiper Fluid, Fog Lights / Driving Lights, Heater (as mentioned above) / Seat Heater.
E. Slippage (driving surface cold, slippery) and Resistance (things run with more resistance and friction when cold) add to the overall lack of efficiency.
I usually go from a gentle 32mpg in the summer (and if I am really carefull, I can easily get 34-35mpg) to about 23mpg (temperature range of -5F to -25F ) in the winter (still being carefull, but not as gingerly as I am in the summer months) period.
Cheers,
MadloR
P.S. I will pm you... so, you know Jim Myers :P
All of what you said makes good sense. I guess the new Atkinson system that warms the ICE up faster is why my mileage hasn't 'appeared' to suffer yet.
You must be a really 'easy' driver. I know mine is capable of getting more but the power difference between this and my 1st model Gen 1 '03 RX300 is soooooo good and smooth I'm having a real problem getting what I got the 1st 5000 miles when I was really gentle
. Yesterday I did about a hundred of combined city/highway with just me and got 30.5 so I'm happy with that. Usually tho I have myself and two other souls on-board and that makes a difference, down to 29.To me, the difference in standard features and power and the smooth tranny alone would be worth the increase in price but when you add in the economy factor then the payoff is very visible.
Thanks again
Last edited by Cruiter; 12-05-09 at 08:37 PM.
12-08-09 | 08:49 AM
#5
Driver
Joined: Nov 2006
Posts: 162
Likes: 1
From: ny
Temperature...
The real difference, is when it gets cold. I am talking Cold cold. Not the kind of weather most people regard as cold. I am talking more like daytime highs of -8F as best case scenarios.
Right now, on the east North coast, the weather is around 32F - 38F and my mileage is on average about 27-28 mpg.
To get the maximum mileage out of your vehicle, you will need to adapt the coast and light throttle (not activating the ice regardless of what speed your driving) technic. Trying to adapt this principle will also increase your aptitude to predicting when the upcoming traffic will come to a stop. Taking "advantage" of the traffic around you will allow you to coast to a stop, as opposed to accelerating to a stop. As well, you will be more aware of the slope of the road your driving on. If you can see any kind of slope that favours less resistance, you use this as a means of being somewhat more gingerly with the throttle, in such a way that the electric motors are ASSISTING the ICE, as opposed to being charged by the ICE. You will understand what I mean, when you begin to put some of the various coasting technics to practice.
Oh, and by the way, ever since driving my 400h I have never incurred a speeding ticket. The vehicle simply doesn't induce the need or want to speed. Just be carefull and try not to annoy the drivers driving behind you.
Cheers,
MadloR
Right now, on the east North coast, the weather is around 32F - 38F and my mileage is on average about 27-28 mpg.
To get the maximum mileage out of your vehicle, you will need to adapt the coast and light throttle (not activating the ice regardless of what speed your driving) technic. Trying to adapt this principle will also increase your aptitude to predicting when the upcoming traffic will come to a stop. Taking "advantage" of the traffic around you will allow you to coast to a stop, as opposed to accelerating to a stop. As well, you will be more aware of the slope of the road your driving on. If you can see any kind of slope that favours less resistance, you use this as a means of being somewhat more gingerly with the throttle, in such a way that the electric motors are ASSISTING the ICE, as opposed to being charged by the ICE. You will understand what I mean, when you begin to put some of the various coasting technics to practice.
Oh, and by the way, ever since driving my 400h I have never incurred a speeding ticket. The vehicle simply doesn't induce the need or want to speed. Just be carefull and try not to annoy the drivers driving behind you.
Cheers,
MadloR
12-11-09 | 01:20 PM
#6
Driver
Joined: Nov 2006
Posts: 162
Likes: 1
From: ny
In a nutshell, the catalytic converter requires a certain temperature range in which to operate and do what it is designed to do.
When it is cold outside, it is only normal that the effect of the cold, on the catalytic converter is much greater than during the hotter months of the year. Therefore the source of heat, is derived from the hot exhaust gasses, which in turn is delivered by keeping the ICE ON. Therefore, ICE ON, hence fuel is required, and therefore mileage will suffer.
Cheers,
MadloR
When it is cold outside, it is only normal that the effect of the cold, on the catalytic converter is much greater than during the hotter months of the year. Therefore the source of heat, is derived from the hot exhaust gasses, which in turn is delivered by keeping the ICE ON. Therefore, ICE ON, hence fuel is required, and therefore mileage will suffer.
Cheers,
MadloR
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