Sure sure, rub it in I had to use the ice scraper today!!

 

Basically I always feel ok when I compare the mpg of my 400h to my old RX. When I read what other people are getting I sometimes wonder why I don't but I know that I don't drive like them and I don't have the "right kind" of trips. Regardless, we're helping the environment, getting better mileage and getting great performance. I love the car.

 

Outside Temperature: 32 degree F

Cruise at 70mph - about 22 mpg
Cruise at 80mph - about 20 mpg

 

Our 2000 RX 300 was EPA'd at 18, we got 15-16 around town (15% less). So, if we get 26-27 MPG in our 2006 RX 400h (15% less than the EPA's number) I'll be completely happy. It's all relative.

 

I always try to keep my engines warm in winter by covering the radiator with cardboard. Its kind of a trick to get it in there on the RX but it can be done. I use the flat compressed cardboard and unroll it in front of the radiator. The engine warms up quicker and it hold the heat in. I never see the temp guage go higher than it does in summer(just under half) And I like it warm in the cabin so crank up the heat.
I do notice that you cannot run on electic power even feathering it on very cold days.
I have almost 12,000 miles on mine now. And yesterday ran 100 mile against a 20 MPH wind and an air temp of 15 degree's, I got 20MPG at 65 MPH.
On the trip back home the temp was 0 and a tail wind of 15. I averaged 23 on the total 200 mile trip, and I was a toasty 75 degree's inside.

 

Very interesting! Being neither a hybrid owner nor a resident of a cold climate, I hadn't considered the behavior of the 400h in winter. It makes sense that the engine will have to run longer to provide cabin heat and keep the cats on the boil at low temperatures. I have had rather extensive experience with batteries - Ni-cad, NiMh, and Li-ion at low temperatures, and all become pretty inefficient at low ambient temperatures - particularly the newer technologies that can't seem to provide more than half of their normal life at moderately high loads in cold weather. I hadn't considered the effect on a hybrid, but it's obviously there.

 

I've got a brand new 2007 rx400h. It's got 1300 miles on it and I've had it for about 6 weeks. I live in Minneapolis Minnesota where we've had what is considered a warm winter so far with temps. in the range of 10 to 35F. A few days ago it started to get really cold with temps hovering at 0. The lows have been at 5 to 10 below the last few days. My mileage has been pretty bad, hovering at 18mpg with aprox 85 percent short city stop and go trips of 7 miles or less, and short highway trips of less than 10 miles. When I first got the car we made a long trip of 800 miles on cruse control at 70mph average. The mpg for that trip was 25.8. This is my first hybrid, so I'm dissapointed. I wonder if this is all that I can expect in weather this cold. This morning when I pulled out (of a heated garage) it was 10 below and the engine was on almost constantly except for coasting of course. The heater was on which wasn't an option. I'm new to this so I've been doing research on how best to drive for optimum mileage. When temps are below 15 I haven't been able to get much difference in engine/battery ratio regardless of driving technique. I'm looking forward to spring so I can see how much of an improvement I'll get with higher temps. Not much info out there on this car in very cold climates. Any advice, information, or encouragement is welcomed. By the way, on the bright side, it's a pleasure to drive, is very comfortable, and quite lux. It's my first SUV (I needed the cargo space for my business), and it was this or the Highlander which drove more like a truck and was noisy. I've got my fingers crossed for better mileage, but I might have to be satisfied with knowing at least I'm putting fewer emissions into the air.

 

A) Mileage is worse for a few thousand miles
B) Winter temperatures bring fuel economy down.

 

Yep, our gas mileage is lower in the winter with our 2006 400h. Another thing is the type of gas some areas have during the winter. The oxygenated stuff gets lower mileage. The ethanol laced stuff also gets lower mileage. The cardboard in front of the radiator trick is a good idea. Toyota/Lexus should offer a shutter option to folks in cold climes. Another factor maybe our tire pressure and rolling resistance changing when the temps drop. Tire pressure correlates to temperature. Rubber pliability also has some correlation to temperature.

 

Drove on the highway only, at a constant 60mph with temperatures at -6.0F (that's without the windchill factor) and was averaging about 22.5mpg. Not bad really, considering was driving on the open road with crosswinds, and slippery road conditions.

 

Ok, now I'm down to 16.8 mpg, this is really bumming me out

 

I ususally use regular gas but when the temps started diving I switched to premium. It was a good move. I've been averaging 21-22.9 mpg and I'm driving in below 10 degrees with negative wind chills. Last winter it was warmer but my mpg plummeted to around 18 so I decided to try switching this year.

 

First 3 months ownership: average 26mpg combined, about 10% hwy, 90% city.

I can coast down a few hills for fun and watch the gauge hit 61mpg. Yeah, sure.

 

Well, I just got back from the dealership and they said that the hybrid system is working within normal parameters. Its just the cold. I asked them about blocking the radiator and they said it wasn't recommended. Well, I'll try premium fuel and try not to keep blasting the heat and see if that helps.

 

I had great success with exhaust wrap, to protect vital components from being scorched from hot exhaust gasses exiting manifolds, catalytic converters, etc... on some highly modified vehicles.

You could, technically speaking, wrap the exhaust, the catalytic converter etc on the RX 400h and it could go a long way in helping keep the catalytic converter hot. Just like the wrap can keep heat away from vital components, the wrap has an additional benefit in keeping exhaust gasses hotter (hot exhaust gasses flow faster than colder exhaust temperatures). So, in theory the catalytic converter would remain hotter therefore requiring less engine running on to keep the catalytic converter up to boil.

Cheers,

MadloR

P.S. wrap is available in many widths and even in sheets. I got crazy once and wrapped my entire 4.7l Jeep GCL exhaust and interior compartment noise from exhaust was like 100% quieter.