I’ve had my 2014 GS350 (95000 miles) for about 5 months now. I believe the advertised MPG is 19 city/ 26 hwy. when I first got it, I was averaging around 17 mpg. I do about an hour of NYC city driving every morning dropping my kid to school. Traffic isn’t too bad. My commute to work is 14 miles, about 90% of that is hwy. my MPG has gradually gone down from 17 to 16 and now in the the 14-15 MPG range. I don’t drive particularly aggressively. I speed up to pass people, but I tend to stay around 70-75 mph when I can. What’s crazy is my kid hasnt been here for the last two weeks, so I’m mainly just driving on the hwy and my MPG is still getting lower. Is anyone getting MPG that low?

 

Gas mileage? Who checks that anymore?

95k and 8 yrs old? Time for a tune up. Are you using premium gas?

 

Heavy traffic big city driving gets me 14-15 mpg, that’s normal. When you say you’re still getting bad mpg on the freeway, are you actually calculating it yourself?

 

Until you do a trip to get some numbers, it is likely just style of driving. If it were anything else, it would pop a service light or check engine code would show up.

 

I have a 2019 GS I got a month ago (22.3k on the odometer). Initially the gas mileage seemed at the low end of expectations, so I put a course of Lucas oil fuel system cleaner through it and it's already gone up quite a bit.

 

I always use premium gas. I’m probably gonna get some stuff done next week.

 

No. I’m going off the numbers the car is giving me. When I was getting around 17 MPG, I thought that was low so I reset the trip meter. It then began giving me lower numbers from 16 all the way down to the mid 14’s now. I would just chalk it up to heavy NYC traffic, but I’m doing more hwy driving now than I’ve been doing in the last few months and my MPG is steadily decreasing.

 

Last month, I drove deep into LI for a wedding. Two hours each way. The highest my MPG went was a little over 20, occasionally hitting 21.

 

I’m getting 15-16 in the city. I have hit 20 on the highway. My 2nd Gen was getting 17, but that power was no bueno.

 

I get 17 or so around town, on trips more like 28 and I'm going 80+

 

On this forum, I’ve seen people claim to hit 30 MPG. How is that even possible?

 

I was able to achieve 30 mpg ogling from San Jose to Chico. All highway driving only and cruise control, pumped gas 1 light away from freeway entrance. Besides that I’m usually in the 18-22 with city and highway.

 

95k, new plugs, new air filter, some Cheveron Techron fuel addiditive cleaner, tans fluid drain and fill.

 

Highway driving, cruise control, having your car in the best shape. I hit 31.7 mpg on a long highway drive. You have to be driving for a while.

You are going to get bad mpg in NYC/city driving, stop and go, short drives, rough roads, turns, etc kills your mileage.

The best you can do is make sure your car is in the best position/shape to get the best mileage.

Over inflate tires a few psi to like 36-37psi instead of 33psi
Take out un necessary weight.
Make sure to keep up on oil changes and air filter changes, clean your air filter if it is dirty.
Try using a fuel injector cleaner like Redline.
Spark plugs with your mileage are unlikely a issue but check them and rub off any surface corrosion you can.

Not much else you can do, you just aren't going to get good mileage in city/stop and go driving.

 

In mostly local/city driving, I get 14-15mpg and I do not drive aggressively (only occasionally). The best i've done is 24mpg on a highway trip from NYC to Atlantic City, NJ.