ler0y

I'm really really obsessed with it. When I drive I think I must drive other drivers insane. I always drive at the speed limit, and accelerate very slowly, and one eye is always on the screen that shows power consumption.

So far, I'm averaging about 8.9 L/100 km, or about 26.43 mpg and I want to try and bring that down.

I'm so obsessed with accelerating with the battery alone that my battery gauge is usually in the purple and I haven't seen it green in ages.

Do any of you notice that when you start up the hybrid, the fuel economy drops like mad initially? I've had mine drop about .5 L /100km, or 470 mpg within just a few hundred meters. I wonder why that happens? But its very annoying.

MadloR

Well, as per your question about the initial mileage drop, the engine needs to create heat and quickly bring the Catalytic Converters up to operating temperature, for obvious emission reasons.

Also, you are probably driving in a city environment and hence by nature since the ICE is running you will obviously consume more fuel and this will cause the initial drop you notice.

As for being more mileage concious, yes absolutely. But just like anything you will eventually ween off this "high". I do enjoying pushing the envelope and try to coast and cruise as much as possible. The very hot and humid days have given me average fuel economy of about 33mpg (simply AWESOME) but that's been with the AC off. When it gets very humid, I do leave the AC on and this extracts a toll of about 2mpg.

And for those times I drive vigoursly and with some stop light racing, I STILL manage 28mpg including the AC. OMG. This SUV rules.

Cheers,

MadloR

SLegacy99

Yeah, its pretty sweet.

ler0y

Ahh, thanks for the explanation MadloR, it was driving me nuts trying to figure out what was happening.

You are getting such great MPG, I wish I could say the same. I've only got about 5000 km or so on it, but the best fuel economy I've gotten per tank has been about 24 mpg.

Lil4X

I don't know about the hybrid, but my RX 330's instantaneous mileage calculation does about the same thing, The explanation is as follows:

Your instantaneous mileage is calculated from both incoming data and data in the trip computer's buffer memory. If you were driving normally say, last night - shut off the engine and left the car overnight - when you start it in the morning, the first thing the trip computer will do is retrieve your buffered data to start its calculation. In a few seconds it will start adding new data to the process, and seeing fuel flow but zero speed, it will start factoring your idling "mileage" (or lack of it) into the equation. Even at low flow levels, zero speed results in really miserable MPG.

Remember, with the hybrid, the ICE will crank when cold in order to lubricate the engine and light off the cats. As you start moving, the computer starts getting speed data and mileage calculations start becoming more realistic. This will take a few minutes to damp out the dip your economy reading has taken, but never fear, all will be well within a few miles. Your "actual" mileage isn't really suffering, what you are seeing is an artifact of the mileage algorithm that is unable to predict that you will shortly put the car in gear and pull out of your driveway. It can only deal with what is happening at this moment, and apply that to what it has "learned" about your driving from last night.

oldcajun

My experience is that your mileage in town will improve if you quit trying to accelerate from a stop on electric power. Accelerate normally to just above your target speed then back off the accelerator pedal to just maintain speed while on electric power. Watch ahead for red lights and stopped traffic and coast up to the stop from as far away as possible. This will recharge the battery during the decel. With practice, you will find ways in your traffic situation to keep the car on electric power as much as possible. It is indeed possible to get 30+ mpg in city driving.
Steve

MadloR

I must say, to attain 33mpg requires driving like having a cracked raw egg under your right foot.

And, it requires much planning ahead and coasting as possible.

Also, you try to follow in a lane occupied by a semi or big rig, since they are the source or most likely to impede fast driving and quick stop and go (of course you don't want to be the car directly behind one). The reason I choose to drive on the highway in the right lane, since you can accelerate and coast much more effectively. Also, I use the cruise control to maintain speed, but NEVER use the resume feature when re-attaining my target speed or use it if the road is downhill. I find it more efficient to turn off the cruise control when coasting down a fast sloping road.

The AC is a real pig on fuel consumption, so I set the AC to a comfortable level 77-78F. I am not one of those who likes to FEEL the AC, but rather to remove the humidity (yes, I where suits and ties and yet don't feel the need to set the AC to "shrink my boyz" temp settings).

I like to set my tire pressures to 40psi in the summer hot months and especially if I am driving on long highway trips. I also have my tires oversized and have factored in the error factor, so technically I am driving with more tire drag. (255mm).

Cheers,

MadloR

nehal51086

i was expecting much better fuel economy when my dad got the 400H...but it turns out that i (is250) get better gas milege than he does...and i have somewhat of a lead foot and accel alot..and dad doesnt.... he got the RX about 2 months ago should i expect his gas milege to go up as the car gets more miles on it?

spwolf

yes, it will get better with time... but your dad has fast SUV, while you have small sedan, thats where most of the difference comes from.

spwolf

how do you average 26 mpg when your best tank is 24?

ler0y

The 26 mpg doesn't average out over a whole tank. It is only for a little stretch. The best instantaneous fuel economy I have seen is 33 mpg. The best average fuel economy per tank is 24 mpg. If I could average a whole tank at 33 mpg I would be very happy.

silvervett

When I first got the car I didn't understand why anyone would care about the gas mileage but I have to confess that I did go through a MPG obsession shortly after I got the RX400H. I basically don't care anymore but when I first got the car I also had a 2003 Jeep GC Overland with the high output V8 engine. 98% of my driving was around town trips to the post office, supermarket, friends house etc under 15 miles with a mix out local streets and expressway. I would get between 12 to 14 MPG. On a long trip with a little stop and go traffic I would get between 16 & 18. The one exception was a trip to TX last June with almost zero traffic jams I got an astounding consistent 20 MPG with the Jeep but that was an anomaly. When I first got the hybrid I was very pleased to get 22 to 24 MPG and I was very pleased to see my numbers go up as the engine broke in. On my last trip to SC I bumped up the air to 38 PSI and did a paper and pencil check to see what the numbers were after the added tire pressure and with about 6,000 on the engine. I seem to get 28 to 30 MPG with and occasional dip to 26 MPG reguardless of if I and at steady highway speeds or stop and go in town. Gas prices in my area are been about $3.50 gal (They seem to drop to under $3.00 as soon as I get out of NY) so switching from the Jeep to the Lexus is almost like going from $3.50 to $1.75 a gallon. I am now driving a car that has all the speed and comfort as my Jeep and yet it only uses less than half the gas of the Jeep. I have pretty much gone through the phase of MPG obsession and am just happy to I only need visit the pumps less often before the guage dips down. My guess is that everyone goes through the MPG obsession phase but eventually you will just accept it as being a normal thing and not dwell on it. I doubt if the Lexus (I have he 4 wheel drive version) will be able to handle the snow as well as the Jeep did because the Jeep had better ground clearance and a better 4 wheel drive system, but at this point I don't care because If all goes well I will be closing on a new house in SC on Aug 23 and I doubt I will see much snow.

SixEcho

silvervett

That is easy to do, you only had a 15 mile reading, I have had my computer readout go to 99.9 for about 5 miles

tod071

ha ha, me too, I can get 40mpg if I fill up gas every 50 miles! I notice that the real reading starts at about 100miles.