I do mostly city driving and am unable to get better than 13.5 mpg. This is with the car being in Eco the entire time.

I know these cars have bad gas mileage, but I'm not getting anywhere close to the EPA ratings. Is there something I'm missing?

 

I’m in NYC and I get about 8mpg doing “city” driving. I guess they mean normal city driving (like free flowing traffic and traffic lights being at least half mile apart), not stop and go bumper to bumper traffic

 

Holy Cow, I hate to hear this. What model do you have? I have a ‘17 300awd and average 19/20mpg city with 26/28 highway. Worst in city has been 16mpg with lots of idle time with a best 30mpg highway, although the on board readout said 27. I say this because sometimes what the car is telling you isn’t always the truth, it’s more of a guesstimate based on fuel flow calculations by the ecu.

 

I can see where that would make a big difference in mpg, like just idling all the way home.

 

yup, car does fine when “idling” on highway during smooth traffic (sometimes even 30+mpg)

 

I have a 2015 IS350 AWD... So the least practical for gas mileage. While gas mileage wasn't why I bought this car, I will still expecting in the 18ish range.

 

Maxxxx is brings up a good point. I think the 'city' EPA rating can be misleading - I believe that rating generically is to cover non-highway driving so speeds would generally be under 40 mph, where you'd be at times stopping at stop signs or red lights. I do not think that rating takes into account sitting in traffic like in NYC or Atlanta during rush hour where it's literally a parking lot, where your car would be idling a lot and not moving much beyond 2-3 mph.

To the OP, if your daily drive involves bumper to bumper traffic regularly, then it would make sense that you'd most likely get below the ~19ish mph city rating. Barring the usual culprits of bad gas mileage (ie. low inflated tires, etc.), how's your driving in the city given you really can't drive fast? Do you find yourself constantly hitting the brakes, having AC/Heat on full blast, or idling for long periods of time during your drives at stop lights?

 

Yeah I do almost completely "city" driving in my 2016 IS 300 AWD and get around 19 MPG. It will creep up to about 20 in the summer time if I am lucky, or dip down to 18 or even 17 in winter (especially if I am remote-starting the car). I think my version of city driving is closer to the EPA's version - lots of tooling around at 35-45 MPH with occasional traffic signals. If you are in bumper-to-bumper traffic, your 13 seems reasonable.

 

Have you done the basic maintenance on the car? Like engine filter if it's stock/clean the intake cone if it's aftermarket(some can be cleaned like K&N using a recharge kit, most can be cleaned using a vacuum or compressed air can). Are you doing the standard oil change intervals? Also I think I read somewhere that in ECO mode it's efficient for certain driving and Normal is better for other driving situations. Speed might be a factor in that, I normally drive in Normal and get 18-22MPH of mixed city and highway driving. Tires inflated at factory specifications? I think the factory tire pressure is 36psi, I always try to stay at this or above by 1-2psi. I usually refill the air in the tires once they reach 33-34psi depending on the weather temperature and season. You can also use Chevron Complete Fuel System Cleaner(I use this every other month, I know it's overkill but I do notice slightly better gas mileage and just want extra assurance there are minor carbon deposits), not all gas is the same and there are over dozens of gas companies in each state so making sure you fill up using Top Tier gas will make sure there isn't performance issues in the long run.

Another factor is if you apply gas when accelerating in traffic and then stopping, I learned to try to just let the car roll in traffic since it's no use trying to get to speed quick and then suddenly applying the brakes. But really it's different per person because not all cities are the same.

 

Thanks for the replies everyone.

The type of city driving I do is not NY City bumper to bumper. I usually only drive this car in the evening since I have a company vehicle. It is a lot of stop signs and traffic lights, but very little traffic. According to my dash my average speed is 23mph.

As far as maintenance, this vehicle has been serviced at the Lexus dealership every 5k miles. It has a new air filter and a fresh oil change as of 300 miles ago. My tires are at a steady 36psi as recommended by Lexus. I always use premium fuel from either Sheetz or Speedway. I use these two places with my other two vehicles and have no problem achieving the EPA gas results for those vehicles.

I will try driving in regular mode after the next fill up and see if that changes anything.

 

Actually gas from some brands differ, I found that Chevron/Texaco and Shell(slightly better) works best in my state but those two uses more detergents in their gas from what I was told. I also heard Sam's Club and Costco gas isn't that bad and some cars get better mileage from their gas. But it really depends on the person so it's not a one answer fits all, just more of a preference and possible placebo. But if you have a lot of stop signs and drive in the evenings then that explains it somewhat since you are always accelerating and stopping but not too sure how often such as per block or so. Try driving in normal mode and see if you notice some difference.

Maybe someone can chime in how ECO mode actually works such as if you were to get up to speed from stop to let's say 25mph, do you use more gas versus in normal mode doing the same. I would think maybe a little more since you do have to give it a push more on the pedal to get it to speed quicker versus in normal mode(purely my thought).

 

The way I have always looked at it is in Eco mode it takes longer to get to whatever speed you want to get to vs normal because the throttle is so limited. I'm probably wrong, but I feel like eco mode wastes more gas UNLESS you drive strictly on flat zero incline roads all the time. I NEVER use eco mode and I have 50% highway driving and 50% city driving, but there are SOOOO many hills everywhere here in Germany that I can only achieve 25 MPG max for the most part lol. That's obviously with my 4 banger turbo which makes it worse, but for Maxxxx that seems like pretty damn ****ty MPG. Those are good points though about how the EPA rates MPG not to mention it is an "estimation".

 

Great discussion everyone, I appreciate all of the responses!

I am going to try driving in Normal mode after next fill up and report my findings. If I can get up closer to 20 mpg I'd be very happy.

 

Getting 25 MPG itself will make me happy, too much random traffic to even get close to that.

 

We can all drive with a gentle foot on the gas (OK, some of us...) but we can not control the speed control or the A/C.
The Drive Mode "Active" ECO setting (you act to turn the **** and the car acts differently) modifies everything that
uses power, throttle, cruise and A/C. Cruise control will traditionally downshift and floor it to maintain speed
up a hill...not in ECO, speed will drop until you are on the level again. Try twisting to ECO mode when the A/C
has stabilized your set temp on a hot day, you will feel the fans ramp down and the humidity rise rather quickly.
Transmission shifts up earlier and the throttle will need a deeper press to even hold your speed.
All this will reward you with up to 7% better MPG.