Hey Guys,

I purchased my 2015 GS350 Fsport last Saturday on June 13. So far I put two full tank of gas and 520 miles on my car. I'm getting a average of 16.3 miles per gallon. I'm driving normal the way I've been for the past 18 years. On my last 2008 GS350 I average at 19.8 - 20.5 MPG.

Why MPG so slow on my new car?

 

It should improve slightly as the car breaks in.

But yes, these cars get lousy gas mileage. Pretty sure my old V8 GS with a 5 speed auto got better or similar mileage.

 

That's pretty much normal. You might see 17mpg once it gets broke in. The car has a slightly better time achieving highway figures on road trips. Otherwise don't expect anything higher than 17-18.

 

Yep our car get aroubd 17.5-18 on city/freeway.

 

Luckily, I have a short commute.

 

You have to drive reaaaaaaal easy to get the advertised gas mileage. Under normal circumstances 16-17 is all you'll get in the city. It does very well on the highway though, I regularly get over 30mpg.

 

I get 19mpg regularly with mixed driving but the current tank is all stop and go local driving, and it's saying 16.3 estimated. I've gotten over 25mpg highway a few times but still haven't taken a long enough trip to burn a whole tank on the highway.

Basically, yours is a little low, and will probably improve as the car breaks in and the ECU learns. Also make sure you put 91 octane or higher in it, and go for 100% gasoline if it's available. This car, like my old G35, does not like 93 and will guzzle it excessively vs. 91.

 

There is no break in period. lol I'm still getting 16-19 mixed daily after 1 yr and 10K miles later.

On the highway my best was 24-27 with cruise control set at 70 MPH with no gunning.

 

What psi do you run your tires on? I had an F sport recently. First thing I noticed was it was a lot less comfortable compared to the luxury so I checked the psi. They were set to 34-36. I thought it was too high since I run 32-33 on mine. I looked at the door and it does recommend 35-36 . You may be running on low psi without knowing. Not sure how it has been driven but the clock shows 22ish which really surprised me. It has less than 5K on the clock.

 

16 ish does seem low... My 13 GS Luxury Package (non F-Sport) with 34 psi tire pressure get 23.9 mpg at 80 mph (most of the time - If I don't see a Mustang coming up in my rear view) when going to work and using the cruise control. I guess you could say this is highway miles. Approx 44 miles a day 22 each way. This is just slightly less than my 06 IS 350 I traded in which I would get 24.6 mpg. Don't do much city driving but noticed times of low 19's.

 

I have never had under 24 MPG in town, 27 to 30 on the highway (2013 RWD F-Sport). I do drive like a little old man.....I am a little old man!

 

This is spot on with what I've experienced.

 

My average is 18.4 right now. It took two trips out of town to get that high though. I normally average 16.5.

 

Around town (30 mph - 40 mph) with all the stop-n-go stop signs and traffic lights I usually get between 16 mpg - 18.5 mpg. Throw in some 60 mph - 75 mph driving and it goes up to 23 mpg or so. All highway driving and it goes up to high 20s. What really drives the fuel mileage down is all the stop-n-go city driving.

 

Yup perfectly normal. I've had mine since '12 and typically achieve somewhere between 16.3 and 17.5 depending on the week. Mostly city driving.

But like others, this thing cruises very well on the highway, 28 mpg at 75 is achievable on flat land!