I drive ~25K miles a year, just passed 72 K miles so I have quite a bit of aggregate data. I drive a ton of highway miles (>80%). I cruise at 70-75 daily.

29-31 mpg everyday, realistic miles before fillup ~445-460, trip computer says 31-34, range ~480-508.

2 road trips, calculated mileage was 33 and 35 mpg (NorCal and Vegas).

 

my 2010 IS 250 AWD averages around 24 with half city/highway driving. I beginning to wonder with all these 30 mpg everyone reports. Is it with the 2006-2008 models of IS 250? Are they AWD? Didn't Lexus change the 2009-2010 models to the new mpg standard? The 2006-2008 were 22/28 I believe and now 2009-2010 with the new mpg standard is 20/26.

 

My 2010 IS250 RWD is averaging 33.1 MPG with 90% highway driving at 65-70 MPH. With the rising price of gas I could not be happier.

Kevin

 

It's because your car is AWD. AWD is the suck for mileage.
Bunch of extra pretty much dead weight most of the time, and having to drive 4 wheels instead of 2.

 

My daily driving is spent 90% within the city, I average 18.2-18.7mph in my 350.

 

I was curious... The people not getting good gas mileage.. Are you rolling on 20"s? Just wondering if that contributes to the poor gas mileage? or are you on stock 18"s? and it's just the city driving?

 

I drove from Fayetteville to Wilmington NC (1 hr 45 min drive) and averaged right at 30 MPG. I kept driving around 60-70 mph. Also, I averaged 26.2 for the whole weekend trip. I couldn't be any happier with the mileage for an IS 350.

 

I'm averaging about 24 MPG over the last 4,200 miles.

You can see my fuel log here: http://www.fuelly.com/driver/rrocket/is350

 

I get about 25~27 MPG (85% freeway) going 75~90 with is350. Im on cruise most of the time.

 

Driving very easy I can get 24-25 going 50/50 city/highway. On long road trips, mainly highway driving at 70-75, 28 is normal.

I did however manage 19.9 highway going an avg. of 120 mph, and topping off at 143 on a 225 mile trip.

 

My last road trip, avg speed 90, and 32.3mpg.....'07 IS250 RWD....so sad that some jerk rear ended me last week when I was stopped at a red light. Now I have to replace this thinking about a AWD....

 

Wtf.....mine is250 gets ~27 65/35 hwy/cty.

 

Why in the world would you want an AWD car in SC?


Anyway, my mileage seems to be improving as the car gets miles on it... early in the cars life I was seeing 27-28 for long highway trips... now it's more in the 29-30 range.

 

Still getting 18-19 mpg, 50/50 freeway and streets albiet work is 8 miles away. I think I hit 22 mpg before and that was driving out 40 miles to see some of my in laws, crusing at 80 mph the whole time with no mad accelorating.

 

I average 20.5 mpg driving in NYC. Stop and go traffic really kills your gas mileage.