AeyBeCei

16.5 sounds about right. In NYC with the traffic the car usually calculates an overall 17 mpg for me.

geigerbran

This sounds terrible. I am getting roughly 24mpg+/- 0.1-0.2 on my 2015 IS350 F Sport. I have the HPS intake pipe, not really sure that is actually helping. 70/30 Highway/City driving. I also keep track of my milage/MPG on an app as well. I hope you figure out what is going on with your car man. Also I did not see where you said what kind of fuel that you use. If you are not using premium I would change to it if I were you.

goldengame

City driving and traffic kills gas mileage in this car. In 100% traffic, I'm getting around 17 mpg with my IS350 AWD. On the highway I get around 30 mpg.

GibbsLexus

iTrader: (1)

I got my car 2 weeks ago; drove it from Atlanta to Charlotte, averaging 29.8 (27 low- 32.8 high) mpg on I-85 (driving in eco mode). However driving around the city and suburban, I'm getting between 19-23 mpg (normal mode). Sport + mode was getting me 16mpg to 22ish but I was getting it. lol. The 350 got some nice power but good mpg if u drive conservative on the hwy. I'm happy with the car.

MWIS350

Something is wrong with your car even V8 ISF get 19-20 mpg.

goldengame

Yeah but that's not exclusively city. The IS-F will get 19-20 mpg combined. My IS gets around 24 combined. Not a big difference, but a difference nonetheless.

Crossxup11

i had a similar problem.

Are you by any chance using Shell V-Power 91?
I used to love that gasoline, but an "expert" at Lexus told me its great for cleaning your engine, but doesn't burn as well as, say, Esso Synergy 93.

I thought it was BS, but since I've switched I swear I've noticed a change. Not in terms of performance, but in gas mileage.

Is it reviewer's bias; am I only noticing because i expect to notice? Maybe, I don't rule that out.

but take it for what it is, not all fuels are the same.

nathantse

I use Chevron, Shell, and Costco. All gave me roughly the same MPG. ~24 MPG for each full tank.

But now, I mostly use Costco because its cheaper and 4% cash back. I fill my tank every week, (~35$), and I still achieve ~24MPG (sometimes 0.5 more or less) per tank on my commutes to work.

tea

I have a 250 and I average 20 mpg. But that's 90% city driving in LA and a 5 mile commute. People will get better "city" mileage that lives in a city with less people, less traffic, and less idiot drivers. I'm sure I'd get worse if I had a 350 and definitely way worse if I had an isf with the same drive

Olasek

I am with my IS350 in Colorado today and filled up at Costco - Costco offers either 85 or 91 octane here - why 85? - because at this altitude 85 is equivalent to 87 at sea level. So I filled up with 85, gas attendant confirmed that I will be fine with 85 if I use 87 in California. Costco was at about 5000' but tomorrow I will take my IS to the Independence Pass - over 12,000' up.

nathantse

Just curious why your're ussing 85/87 when the IS350 requires premium, 91.

Olasek

No, it doesn't.
The dealer confirmed that.
I do not want to get into repetitive nuts and bolts argument here - it has been recently discussed in the chat forum here.

EZZ

People spend thousands in mods to squeeze out tiny amounts of hp. You taketh away the power gains to save a few dollars. Should have gotten the 200t

nathantse

I work at a dealer and we always tell customers to use premium. It even says so in the manual and there's a sticker behind your gas cover stating so.. But its your car.

Olasek

There are no 'power gains' a driver could detect, actually many drivers report better power with lower octane, but if there is anything there it is virtually undetectable, its bunch of poppycock.