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Hybrid Vehicles Lexus RX 400h Lexus RX 400h: Driving Tips & Tricks
110 messages, Last post on Sep 10, 2007 at 8:21 AM
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| It is an interesting phenoma how the mpg drops so quickly waiting for a light to change....Wife pointed out that maybe if there were more miles driven it would drop more slowly...I drove the bmw down the mountain around eighteen miles..UP and down but generally dropping..Got to the little community, and pulled over to mess with the i drive which is tedious...MPG dropped from thirty two to thirty in nothing flat..Started the drive back up the mountain and the mpg rose very quickly back to thirty two and a bit...Got back near the house and got the two lights and it dropped back to thirty just lke that..Went the next mile and a quatre and it was back up to thirty two...I was very impressed with the mpg for the longer trip, but I feel if I had been stuck in traffic at all it would have been much lower...Seems this stationwagon 5 gets eighteen in traffic and city and thirty or more on general road..Next to check out interstate at eighty mph Tony ps I place this report here as we almost got the rx h and think the board would be interested, as I would be if the shoe were on the oher foot... | |
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We had 4 inches of snow here in the western Midwest last night (Wednesday night). I needed to be at work at 4 AM this morning. Since my snow tires have not been installed yet on my LS430, I decided to drive my wife's RX400h to work. The streets, for the most part, were not yet plowed. I had absolutely no trouble at all in the snowy and icy streets. The car had wonderful control. Even stopping at stop signs going down hill was a breeze. To summ it up, the car handles very nicely in this type of snow & ice. By the way, the tires are all season tires (nothing special). On another note however, I have been finding that the gas mileage has dropped off substantially with the colder weather. We are now only averaging about 23-24mpg on the highway & about the same in the city. In the summer months we were getting about 27 on the highway & at least 30 in the city. Driving home today (city driving) in 20 degree weather, I averaged only 22 mpg. Has anyone else seen this type of dramatic drop in gas mileage or has something gone wrong with our vehicle? The gas engine seems to be running a heck of a lot more than when it is warm. |
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Replying to: cyclone4 (Dec 01, 2005 8:32 pm) |
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Replying to: cyclone4 (Dec 01, 2005 8:32 pm) You are a victim of Mother Nature, mi amigo !! Cold weather reduces MPG in ALL cars, not just Hybrids, but it's more noticable in hybrids because we all care so much about the MPG. Here are some reasons why you will see reduced MPG all winter: Getting low MPG in cold weather is not a problem with hybrid technology, per se. If it was, there would be ZERO drivers achieving EPA numbers in the winter months, and that is not the case. There are many reasons for cars not achieving max MPG in the colder months... Car engines must warm up to a certain internal operating temperature before they most efficiently use the fuel. Winter months and colder temps make that transition from cold start to most efficient take a little longer. Also: If your car is relatively new, new cars go through what is called a "break-in period" where the metal engine parts are still grinding against each other more rigidly, creating more friction, which also reduces efficiency. Over time, the "extra metal" shaves off and gets lubricated better (expecially if you use Synthetic Oil) and the friction is reduced, which affect MPG numbers. Winter formula fuels used in most states hold less energy and this also hurts MPG. Generally speaking, colder weather in many areas means "rain, snow, or slush or ice" on the roads - these things add additional resistance which the tires must push out of the way to contact the road, so they hurt MPG in that way. Tire pressures also are lowered by the cold weather too. Most people fail to properly inflate their tires all year, but ESPECIALLY in the winter when it is cold and you might have dirty tires and you just dont want to deal with spending time in the cold airing up a dirty tire. Low tire inflation can cause blowouts and adds quite a bit of rolling resistance, which forces the engine to work harder to "push" the car forward, thus using more fuel. Additional idling uses more fuel and hurts overall MPG, and many people in cold climes by habit or necessity are warming their cars up in the morning. That is good practice to stay warm, but BAD for MPG numbers. While idling in your garage or driveway or carport, it is getting 0 miles to the gallon !!  People who use the defroster in a Hybrid are many times using the A/C compressor to help reduce the humidity in the car and clear the fog. That is a MPG killer too. The compressor can be turned off, but usually by default it comes on. See this science page for more explanation: http://tinyurl.com/3s7lo You might want to invest in an Engine Block Heater, which will help a lot in getting your engine up to prime operating temperature faster. I'm getting one for my 2004 Honda Civic Hybrid very soon. Good Luck, and hang in there !!!
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Replying to: larsb (Dec 02, 2005 6:06 am) |
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Replying to: larsb (Dec 02, 2005 6:06 am) Now, I'm sure Toyota thought of this and has installed heaters in with the batteries to keep them within certain thermal limits, but it still takes time (and energy) for those heaters to take effect. As for the tire inflation pressure. It needs to be clear that you still only inflate the tires to the recommended COLD tire inflation pressure, regardless of the time of year or the weather. Having said that it is true that city driving will probably not raise the tire temp to optimum levels and this could affect your MPG. Highway driving should still heat up the tires, so you don't want to overinflate them and then get on the turnpike where the tires will be dangerously overpressurized.
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Replying to: skyfish400h (Dec 06, 2005 11:28 am) Since my commute is short, less than 10 miles each morning, I lose MPG every day due to the warmup not happening fast enough, regardless of my battery charge. The battery can be 100% and it will not matter at all if the software is not using the electric drive. |
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Replying to: skyfish400h (Dec 06, 2005 11:28 am) Most battery chargers controlling automative battery charging, alternator output voltage, have a method of sensing ambient temperatures and will charge the batteries to a higher voltage level as temperature declines.
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Replying to: wwest (Jan 03, 2006 7:42 pm) I think they heat the battery compartment. Batteries hold charge better when cold, but they provide energy better when warm...
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Replying to: stevedebi (Feb 03, 2006 2:46 pm)
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