coldsoda

UPDATE: after a full 1,519 miles without resetting the computer mpg calculations, it is exactly the same as my manual calculations (I use fuelly). 22.7MPG with 38 miles of freeway and 4 miles of streets each way to work every day. No real rush hour, steady moving on the freeway between 55-75 depending on traffic flow.

asiandavid

I just got the is350 fsport with an exhaust doing 11 mpg the exhaust cant impact it that much can it? Car currently has 600 miles and i read in here that theres a breakin of 3k miles for better efficiency? Can anyone confirm

Avi8orco

I got mine in Dec. First tank of gas 18 avg. Second 18.9, Third 19.4. I have just under 1000 on the clock. Dealer and many others said it improves after a few fillups till it gets steady around 22. I'll buy that as mine seems to be following suit. No mods other than F sport drop-in filter.

dman51

I have a '16 IS300 and am about 50/50 highway/street and after numerous fills now over 1,200 mi I'm still squeezing by with about 18mpg driving eco 24/7. It's the one aspect of the car I haven't been satisfied with. I'm stunned to see those with 350s getting 20+. My best tank was 20.5 mpg but that was 75% highway so I'm not sure whats been going on.

EZZ

18-19 mpg is normal. I have a lead foot and I get about 18. Price I pay to have a little fun

SLMis

I go a short distance daily without a chance to warm up, pretty much 5-8 minutes of stop and go traffic and park. Most days pretty lenient on the gas but still average 12.5 unless I go around town more then the average might go as high as 13.5. No performance mods, stock.

evident

that really just sucks, an M5 or S63 AMG probably gets better gas mileage. might as well drive those cars, LOL

asiandavid

Im on the same boat only mod i have is an exhaust and i manually calculated it and its averaging 11 mpg this is horrible mpg

nathantse

2016 is350 fsport..

I filled it 3 times so far.

1st time, drove off dealership. I got about 15-16mpg

2nd time, self filled. I got about 18-20mpg.

3rd time, which was yesterday. Im getting like 22-23 mpg.

I drive pretty conservative, I go in eco on freeways, normal/sport on streets.

But a full tank says the range is ~300miles.. is that normal?

asiandavid

i think this is normal i havent seen mine go to 18-20mpg yet on second fill still at 12mpg

F Monster

Damn, y'all IS350 F-Sports is getting the same gas mileage as my ISF. I average about 275 miles on a full tank which contains 14 gallons. 275 miles / 14 gallons = 19.65 MPG.

nathantse

My car is still new.. less than 500 miles. I'm getting a combined of 22-23 MPG right now. Hopefully it will get better in the future.

jkonquer

I get 19-20 mpg/street on 14 is350 f sport. My average mileage is set at 19.5 with 3000 miles of only street driving on all mode.
I have gotten as high as 30 on highway driving, but it was short period of time so it may not be precise.

goldengame

On average, I get 22-23 mpg in my 2015 IS350 AWD with 60 highway/40 city. On the highway with my winter tires, I managed to get a high of 33 mpg. My city only mileage is around 19 mpg. I'm not sure why there are so many people in this thread getting bad mileage; my mileage has been about the same since I got the car from the factory (no real break-in period for fuel economy).

ExSrAaron

Overall average 22-24 mpg (mostly Eco/occasionally Sport+). I track gas mileage with Fuelly.

Driving aggressively it'll dip to around 17-19 mpg (Sport+). Trackdays are around 8-10 mpg. Highway road trips 26-27 mpg. 8 spd IS350 F Sport RWD running 93 octane and performance tires.