I recently got my 2021 IS350 and I noticed I'm running 13-14 mpg, that's using more gas than some big liter v8s. Is there something wrong, don't think this is normal. I bought the car used with 35k miles. I run 93 for gas

 

Take it in for warranty. Could be bad sensors, injectors, something mechanical. Even with a heavy foot your mpg shouldnt be that bad.

 

I know this doesn't help entirely, but beyond what richieca mentioned, low MPG could be related to a variety of factors - your normal driving style, whether your tires are inflated to the proper PSI, mostly highway vs. city driving, etc. Also, since it's winter time, gas stations generally use a winter blend where more detergent additives are in the gas itself compared to summer blend - that within itself could be a huge factor.

 

I live in Miami so I have no winter factors playing into this.

 

Would run a bottle of Fuel Injector cleaner and see how it does. These cars have in general arent great on gas. I average around 18-20 MPG locally, all highway i can get up to 26-28MPH.

But if you either have a heavy foot or are in stop and go traffic 13-14 is right on par LOL

 

I have 22 IS350 FSport and never achieved anything above 20-21 MPG, but I’m driving more aggressive than typical people, also there is a lot
of stop/go traffic in my area when going back from work so sometimes I average 15-18 MPG in between filling up.
I also put 93, and I usually have AC on like 90% of the time so that could be the factor as well.

 

Conversely, my lifetime average in my 2021 IS 350 is 22 MPG, but I work from home so can avoid the traffic in my area. I've also done a number of longer highway drives. I have gotten as low as 18 MPG on one tank.

So the situation in which you're driving matters a lot.

 

I'd chime in with my IS250, 95% city driving 5% hwy and i sit around 16.5 mpg (14L/100km)

 

I get 19 mpg between every fill up and always use a/c as well. Lots of traffic but i do mix in some highway use too.

 

Are your units in MPG(US) or MPG(imperial)? MPG(US) will read lower.

 

Have nearly 33,000 km on my 21 IS350 AWD and have averaged 21 mpg over that time with predominantly city driving with the occasional spirited driving. Seems to be on par for the course.

 

OK, I don't want this to turn into an MPG show-and-tell.

@FennyMike have you any updates for us on this topic? Still getting low MPG? Personally I'd be at the dealer by now if it had lasted this long.

 

Yeah, my mpg's are much better now, still not the best but that is because I am catless without a tune, so I am running rich. Turns out I just have a heavy foot and stop and go traffic in Miami does not help.

 

Stop and go traffic murders it: I get around 13-17 .
If you drive manual and accelerate hard at red-lights: 6-10 MPG

Highway/empty roads where no need to brake: 30-40 MPG if you drive in gears 5,6,7 and low revs.

The trick is to coast in high gears and occasionally accelerate to keep momentum going. I learned this the hard way after 4 years of ownership.

Living in a big city with a car like this kills it. If you had it and lived in low-traffic rural area roads no worries.

 

"The trick is to coast in high gears and occasionally accelerate to keep momentum going. I learned this the hard way after 4 years of ownership."

Yup, I learned that the hard way as well, drive in eco to go to 8th gear as fast as possible and then coast, hit the throttle every so often so the car actually moves, that's the only way to get okay mpg's in a very heavy traffic city.