Modeler

I just returned from a trip from Washington DC to Virginia Beach, which is about 200 miles away. On the highway I used the cruise control to set speed of 74 mph (9 mph over speed limit hoping cops would leave me alone ), but had to occasionally speed up or slow down a bit for traffic. The resulting mileage was 31.4 mpg , which I consider pretty damn awesome.

We choose my car for this beach trip with two kids despite its challenging trunk over my wife's 2005 Honda Odyssey minivan. The minivan gets dismal mileage at real life highway speeds. At 74 mph it gets about 22-23 mpg, which really sucks relative to the stated 29 mpg highway mileage. My GS450h actually gets better mileage than was on the sticker.

lucasb7

I realize most people refuse to actually go 65 but when I did (I had to...) It reported 38.6 which is pretty darn good for a car with this much power.

Modeler

You must have been going downhill

I did tests of mileage on short (a few miles) flat stretches of the highway at different speeds, and my speed in the 450h did not vary much between 60 and 80 mph. My mpg at 60 mph was 32.6, and at 80mph it was 29.7.

lucasb7

I was using the method of accelerating then coasting (I forget what it is called, I read about it on the prius forum). So jolt to 70 coast to 60 over and over. works well and makes slow highway driving more fun!

borg1of2

I would like to ask what you are using to measure your MPG. Are you using the GS' computer, which reports the average for that tank, or are you calculating the mileage based on miles driven and the amount of gas you put into the tank? I ask as I am getting dismal MPG on my GS 450h and have been really concerned as to what I may be doing wrong.

lucasb7

I don't know who your asking but I'll try and help any how.

I use both the tank average in the center and the trip info screen. I have also noted that I get at least 375 miles per tank.

I too was having trouble getting good gas mileage in the beginning. But then I found a sweet spot, I was often pressing down on the gas petal too hard. If I came back a bit I held my speed and the milage soared. I find that the current milage gauge in the center instrument panel to be especially helpful for this. When cruising on the highway I slowly let off till the gauge hits anywhere from 25-35 and it seems to work for me. Also if you let the mph drop a little bit when going up hills it helps your milage a lot.

borg1of2

Sorry, I think I was asking both of you as you each indicated you were getting way better gas mileage then I have ever gotten. Currently I am getting, maybe 24 MPG. My driving is fairly simple 17 miles each way to and from work. Even on trips where I head over to Orlando I maybe was getting 27 and that was running around 78 mph with the cruise on.

I have spent time watching the mpg screen and the engine/electric motor screen to try and see how my foot pressure may or may not affect things. I think I generally give up and just press on the gas and accelerate, so I guess I have a lead foot and no patience. LOL

Any other tricks to improving and maintaining high gas mileage?

Modeler

I use the Trip Info screen for the mileage.

My mileage has increased from an average of about 22 mpg at the beginning to the current 24.5 mpg for my regular commute (about 12 miles each way -- mix of about 70% highway and 30% suburban). The increase is due both to the break-in of the car, as well as a somewhat different driving style. While I still occasionally accelerate like a maniac and break hard, these episodes are now further appart than before, when it was like 60% fo the time.

Ikonz350

iTrader: (1)

my brother gets 37mpg in his 2006 Lexus gs300 on snow mode going 65 on cruise control on the freeway.. just wanted 2 let you guys kno.

drpepper

I have to ask...about all of these people posting pictures of Tank Avg MPG in the high 30's or posting that they are getting that kind of mileage, are people actually averaging this economy (i.e., taking the actual gas used for an entire tank and miles actually traveled) or going by the display at some arbitrary point in time?

How are the displayed numbers derived? It's clear that the car's computer has the ability to read the amount of gas in the tank, but it seems like the display is not using actual consumption, but is taking stock of conditions (speed, rpm, distance, etc.) and applying the momentary economy that "should" apply under a programmed model/table and then averaging snapshots. If that's the case, an "abnormal" driving condition, like of coasting at high speeds can be used to skew the the number.

If multiple people are driving "normal" units of the same mass produced car, inside of the typical range of driving habits, there is no reason why there should be individual significant outliers, is there? If 9 out of 10 all get actual consumption of 26 to 29 MPG for extended highway trip driving, what is the reason that the 10th in the same car would get 38.5?

Modeler

Sorry, but your brother is full of it! A 37 mpg mileage at 65 mph is not possible on a V6 engine unless you're going downhill!

Ikonz350

iTrader: (1)

I was actually there 2 take the picture, Just 2 let you know we live in the valley and the freeway is straight, no hills or anything.

drpepper

So, you were witness to a numeric display That's not the same thing as knowing what the actual average fuel consumption was.

Everybody with that same car should get similar fuel economy under similar driving circumstances. There seems to be a few (couple) people claiming average economy approaching 40 mpg for highway driving.

Would you agree that all other properly running GS300s should get the similar mileage to your brother's under similar driving conditions?

What do you credit his remarkable mileage to?

supermaz

I did a 220mile trip at 37.4 mpg. Took me 4hrs with a stop. Thats 20 miles urban, 45 miles country roads average speed around 40mph-60mph hilly windy roads) and the rest 80-85 down a motorway. I though that was pretty good done the journey twice since could only get 35mpg!

drpepper

Did you calculate your actual gas mileage or is that what the display said?