clellandm

IS250 AWD, less than 3000 miles on the odo. 46 miles round-trip to work every day, about 12 of that on surface streets, the rest freeway. Probably average 75+ mph on the freeway, and my tanks of gas have been pretty consistently at 24.8 mpg.

I was hoping for a little better, but by the end of the day I'm not in the mood to see the 'speed circle' light go out!

Xanadu350

City/Hwy 80/20 ECT button always on.
Avg 21-22

The other day I drove 60 miles straight hwy no stopping and I can get over 30 MPG. Stop and Go City it drops fast.

But still I think anywhere between 19-22 in city only is pretty darn good for this much HP. I'm not complaining. Shift it to S4 in city and have fun.

vdubturbo

I only have 1,550 miles on my car, but I usually get 26 on the highway and 19-20 in the city. I'd love to get 28 Hwy... and I think I could squeeze it, but its sooo hard not to jump on it once in a while :-)

slowandlow

25 mpg highway @85mph AWD
17 city summer
15 city winter

IS350HKS

iTrader: (4)

I don’t know how all of you with the 350 can do 20 or +... I drove really slow without passing 2.5 rpm, 65 on the highway I can get 23.5.. However after that I go back to the man would drive my avg is only 16.1 without flooring it.

MIA IS250

95% city 5% highway Avg: 23.7 miles/per gallon

SC300T

09 IS250 AWD -- Only 450 miles on the Odometer... First couple tanks are averaging 31mpg pure hwy at 70-75mph (flat highway). Cold city suburban driving is more like 22mpg (7 mile commute). This is what the trip computer says. I then filled up and measured by hand and the reading I got was around 1mpg less than what the computer says. I'm hoping for an honest 23mpg city and 32mpg highway once it gets broken it. City mileage improves dramatically once the car gets warmed up and the converter locks and it climbs into 6th gear.

07-IS350

Lexus states that the IS doesn't have a lock-up torque converter, at least the 06-07 don't.

greg0723

when i got my car (winter 08) avg 25 than in the summer went up to 29 and now back to 25.4 this winter. all depends on the weather and i drive the same 70mph on the highway all the time. 85 highway 15% street

SC300T

The converter on all automatic IS models certainly does lockup. Virtually all modern slushboxes have lock-up torque converters. Lexus has used them on all of their conventional automatics since Lexus was born. On the IS, it is a "flex" lockup converter that locks up in 4th, 5th and 6th. I'm not sure, but it may even lockup in 3rd. It does only lockup after the transmission temp reaches a certain point.

SC300T

It could just be that your city route isn't the same as others. Cold weather, longer / more traffic lights, ATM visits, drive through window visits / hills. These all hammer your mileage. Reset your avg. speed and see what it is on your route, it could be really low with lots of stops. You could also try easing off a bit more, get it to shift at 2000rpm or less. I know that is really granny driving. Also, if you see a red light, let off the gas immediately and do more coasting. Try going the speed limit. Before stops let off the gas and coast down the first 10mph or so before hitting the brakes. Just a few ideas.

Kurtz

iTrader: (1)

Lock up on an automatic torque converter has been fairly common since the late 70s/early 80s... I can't recall the last time I saw any manufacturer that didn't use the feature on an automatic car transmission.

I know for a fact Toyota has been using them going back to at least 1982

acefalcon2

iTrader: (20)

RWD.... 23 in summer 20 in winter....

AKIS350

Half City Half Highway 24.5mpg
I got 30.3mpg once all highway

vdubturbo

Seasonal gas formulations might play a role in that too. Those are encouraging numbers.