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Really low MPG?

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Old 02-18-09, 07:38 AM
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vmcgarve
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Default Really low MPG?

I have never gotten the posted mileage on my 2007 rx400h -- I have peaked at between 23-24 MPG. Recently my MPG has plummted and I am now getting 16-18MPG. The dealer says everything is fine. I have not changed my driving habits and am even more conscientious about "gliding," etc. Anyone else have this experience? Suggestions?
Old 02-18-09, 07:43 AM
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DaveGS4
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This probably wouldn't account for as big a change as you note but can make a significant difference.... when is the last time you checked the tire pressure in all your tires?

Have you changed gas brands / grades / stations?

Just starting with the simple stuff
Old 02-18-09, 07:45 AM
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O. L. T.
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A lot of accelerants are being used in todays gas, politics as usual IMO.
Old 02-18-09, 07:46 AM
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vmcgarve
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No changes. Same regular station, gas. Have checked the tires a lot (low pressure indicator kept going off -- turned out to be the spare). Just in to dealer for 15,000 service. No significant change since then.
Old 02-18-09, 09:40 AM
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jrobe
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What do you see on your energy monitor when you are only getting 16-18 mpg? It must never run just on the battery/electric motors to get mileage like that. In fact, the Rx350 gets better mileage than that.

Something is clearly wrong with your vehicle. It would be impossible for me to get mileage that low, even now in the winter. I have even towed my 2000lb boat on trips of 300 miles + and still gotten 18-20 mpg.
Old 02-18-09, 10:05 AM
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Lexmex
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Welcome to the Club.

What brand of gas/octane are you using?
Old 02-18-09, 10:48 AM
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NeoNz
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thats not good, are u taking alot of 5 min trips? in start up around town i only get 10 mpg for the first 5 mins sometimes or even less depending on where u are
Old 02-18-09, 11:45 AM
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lots of quick trips will kill MPG because the motor stays on to warm the engine.

also, using your heater will keep the engine running at stops to keep the heat going.
Old 02-18-09, 02:17 PM
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Joeb427
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Winter blend gas and warm ups?
Old 02-18-09, 02:36 PM
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herbvdh
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Originally Posted by vmcgarve
I have never gotten the posted mileage on my 2007 rx400h -- I have peaked at between 23-24 MPG. Recently my MPG has plummted and I am now getting 16-18MPG. The dealer says everything is fine. I have not changed my driving habits and am even more conscientious about "gliding," etc. Anyone else have this experience? Suggestions?
The biggest culprit right now is the weather with it being cold out the gas engine must run more to warm up thereby decreasing your gas milage. I have dropped about 10% to 15% decrease in my gas milage. As outdoor temperature goes down so does your Miles Per Gallon.
Old 02-18-09, 03:01 PM
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oldcajun
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Originally Posted by herbvdh
The biggest culprit right now is the weather with it being cold out the gas engine must run more to warm up thereby decreasing your gas milage. I have dropped about 10% to 15% decrease in my gas milage. As outdoor temperature goes down so does your Miles Per Gallon.
Exactly right! The only source for cabin heat is the ICE so when it is cold out, it runs to keep the cabin warm. For short trips, it will also run to heat the catalytic converter. This is one of the real limitations with the hybrid system and one of the as yet unsolved issues for plug-in electric cars. The real "sweet spot" for hybrid operation is the crowded freeways of Southern California. The least favorable operation would be open freeways in some place like North Dakota with little traffic, no stop and go driving, and cold outside temperatures.

The new 450h has some modifications to the ICE to improve the situation.

Steve
Old 02-19-09, 08:48 AM
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jrobe
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I live in northern Wisconsin (about as cold as you can get in the US) and I have my heater and seat heaters on almost all of the time. I still average over 24 mpg in the winter. I took a 500 mile trip last weekend on the freeway (72 mph) with the heater on and averaged over 25 mpg (regular gas).

If he is getting 16-18 mpg, something is wrong unless he is making 5 minute trips only in Nome, Alaska.
Old 03-06-10, 09:08 PM
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never tried this.. I don't think anyone suggested it either

http://us.lexusownersclub.com/forums...30&hl=learning
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