silvervett

You are correct and I think all hybrids work that way but even though the A/C is powered by the Hybrid battery it still cuts your MPG. For instance if the power is being drawn from the hybrid battery to power the A/C there will be less available to propel the car. So at some point when you are going up a long hill there won't be anything left in the hybrid to assist you and therefore the ICE will have to work harder and your MPG will drop




I never turn on the A/C until the outside temp gets to about 100 because I love the heat and hate A/C, but if I have a passenger in the car I turn it on for my passengers comfort. And when it does go on I set it to 80 or higher and let the passenger set their side to as low as they want. One thing I noticed when I had the RX hybrid was when sitting at a traffic light with the A/C off the hybrid battery would stay on full charge. But with the A/C on and if there were a lot of long stops a lights the hybrid battery would need to be replenished often and the ICE would have to come on fairly often.


On thing I have noticed with the 07 RX and the 08 GS, you can hear the ICE kick in and hear it running but the display does not indicated the ice is rinning when stopped. But with the 08 GS the display does indicate everytime the ICE kicks in.

borg1of2

So, I used this thread to try out a couple of things I was curious about with mileage on my GS450h. The first was a full tank of watching the mpg meter on the display and doing my best to keep the at speed driving, not acceleration or deceleration, to around 30 MPG as best I can. The other thing which was more important was to actually track milage and gallons for this trip against what the Tank MPG had on the display. Here are my results.

Driving was local town driving, no highway on this tank.
Total Miles driven on tank - 384
Total Gallons to fill tank after 384 miles - 13.128 Gallons
Avg MPG based on the above is 29 MPG.
Lexus Display for the tank showed 24.5 MPG.

So, my conclusion is that I was able to get 29 MPG actual mileage on this tank of gas, which is really pleasing. Second is that the display MPG for the tank obviously factors in other aspects of the driving that the true miles to gallons revealed. Not sure what those factors are, but it was an interesting finding.

I will try this again on the next tank to see if I can repeat the above. Thanks to all on this thread.

silvervett

So far I only have 254 miles on my 3 week old car.

I topped off the tank and drove 86.5 miles on 3.28 gal which = 26.33 MPG, I forgot to write down computer read out but I think it was 28 or 29

Second fill up yesterday 109.4 miles on 4.25 gal = 25.74 MPG, computer reading was 28.2 MPG

When I traded the RX400H with 17,000 miles it was getting 30 to 33 calculated paper and pencil MPG. I expect the GS to improve.

By the way I was able to get the RX read out to 99 MPG, and right after the fill up in the GS yesterday I got the computer read out to 55.9 MPG


PS most of my driving is local back roads 30 to 45 MPH
There is no doubt in my mind that I can get the Computer read out in the 450H to 99 MPG but it would be pure BS. The computer is an optimistic estimate but the only thing that counts is the old fashioned paper and pencil method

ReyRey305

iTrader: (3)

I have gotten 29.8 on my 2007 GS350 (full tank of gas) going between 60-65 highway driving... And NO and I am not going downhill because Florida is at sea level !
I am really surprised to see this car get that kind of MPG... The K&N filter probably helps about 2-3 miles per gallon...

slk_dds

Last time I took a 200 miles trip, and yes I did reset the trip computer each way.

One the way to visit my friend, traveling average of 80MPH, resulted in 27+ MPG.

On the way home, traveling average of 100MPH, resulted in 24+MPG.

silvervett

To get an average of 100 MPH you would need to do a lot of driving at 130 to 150 MPH to make up for stop lights and driving a low speeds through town on your way to the thruway

drpepper

For arithmetic average (mean), that's true.

He could have meant he was "most often" going 100, and that is a type of average as well

2thfixr

Here's a screenshot from my GS350, 30.3 mpg mostly highway with quite a bit of city stop and go.

Modeler

Right, "quite a bit of city stop and go" and an average speed of 61mph. Are you trying to fool us, or yourself???

2thfixr

Aha! A doubter! Well.... actually there is a little story there. My actual avg highway speed was around 80mph. Totally true! I have an office 2 hours away from my home. I have another home literally around the corner from my office out of town so I walk to/from my office. I use the car to get groceries, go out to lunch/dinner, and go to the video store (a.k.a. quite a bit of city stop and go). Total distance is 111 miles on that screen because I gassed up which reset the trip computer to 0miles/0mph/0mph and immediately jumped on the highway. My avg highway speed was at least 80mph (rural highways with a speed limit of 65mph but completely desolate at the time of night that I travel) + avg in town speed of XX and what do you get? You get quite a bit of city stop and go to take an 80+ mph avg to 61 mph. No trickery there!

Now for the kicker.... during part of that highway drive, I tucked in VERY close to a reasonably fast moving semi so I had no parasitic aerodynamic loss. You should have seen my avg mpg when I left the semi!

Obviously this is not the norm, a GS350 will not get 30.3 under normal conditions. However, at real world speeds, paying attention to throttle input, minimizing braking, minimizing jack rabbit starts, and a little bit of aero assistance... 30.3 is very doable. Traveling 300 miles round trip once a week is tedious at best so I have a lot of free time on my hands. My personal best is over 32 MPG but don't have a photo of it. I will try to post a better one from the same starting point the next time I get bored.

Jace7

wow, loving the milege you are getting Robert.
That's more than double of what I am getting these days.
But my GSX-R gets around 50mpg so there.

2thfixr

Jason, you play you pay. Congrats on the CGTS, I didn't know you picked one up. Did you get the exhaust?

** Sorry for the threadjack.

drpepper

Okay, not trickery, but what's your definition of "quite a bit" out of the hour and 48 minutes of driving that would get you to that mean of 61 mph? 20 minutes, 30 minutes?

Where's the dividing line between "quite a bit" and "some?" I think that's the issue

2thfixr

Quite a bit = more than some = way more than a little = less than a whole lot.

silver2000

Every time Ive done the math my math was within .1 or.2 mpg of the display

Im leaving tomorrow on a 3400 mile trip round trip - Ill get plenty of chance to see just what kind of highway max I can manage - Im unwilling to go 55 on the highway but Ill see what the RWD 350 will do for 300+ miles at 70mpg 100% highway

One question - Since Ill be going north will that be considered going "up hill" for MPG considerations ??

I bugeted the trip with an average MPG of 25 which I know I can easily beat

At 25mpg I should spend about $522 on gas for the trip - if I can get it to 29 mpg average the cost drops to $450 figuring $4.50 per gallon - with the recent oil price drops I should be able to average closer to $4.30 a gallon - which will save another $20