i just drove my dad's 2014 base GS350 on mostly freeway for 1.5 hours and got from what it was, 22 mpg, to 24.3 mpg.

That was on normal mode, automatic (no paddle shifting), and careful use of the gas pedal and coasting.

 

Just came back from Boston to Niagara Falls family trip. 4 adults. 2 carry-on size luggage.
Distance: ~950 miles
Average speed: 64 mph
Average MPG: 24.1 mpg
97% highway. 3% city.
ECO mode ~30% of the time on freeways. Premium gas on the way there. Regular gas on the way back. No big difference. A/C on low 50% of the time.

2015 gs350 awd. 2500 miles on the ODO at the beginning of trip

About 4mpg worse than our LS460 on trips. Much less comfortable. Driving the car for 3-4 hours was good. Riding as a passenger was uncomfortable after a hour. The seats were too hard.

 

yeah what's up with the hard leather seats?? thought it was just my dad's GS.
We had a loaner ES350 and those leather seats were as soft as pillows, very nice.
I hate ECO mode, I think normal mode would save you more gas if you concentrate on correct gas pedal usage.

 

i drive to NYC this weekend. Combined 24mpg: 80% highway, 10% traffic, 10% city. It comes close to 27mpg on just highway. I have 2013 gs awd btw.

 

I'm getting 20mpg and I'm not even driving it hard, 91octane. I was hoping for little higher mpg, oh well

 

In the past, I found that with gentle driving I could beat EPA estimates. It seems in recent years the advertised fuel economy is less accurate, and this is after the EPA changed the methodology to allegedly align with real-world driving conditions.

I'm not sure if it's the modified test, or whether manufacturers are trying hard to game the system since buyers are more interested in advertised fuel economy than in days of yore.

I don't mind poor fuel economy, I do mind false advertising. It seems lots of folks are getting considerably less than advertised for 'city' driving conditions. In my opinion, 'city' should represent the lower end with the exception of aggressive driving.

All that philosophical rhetoric aside, I can get far better mileage than a typical Texas pickup truck and have a whole lot more fun doing it.

 

2016 350 F-Sport, I drive aggressively and average 22-23 mpg per tank. When I drive nicely it gets 38-40 mpg on Florida highways.

 

Eco mode doesn't help much on highways, so don't bother. It's made for city driving or stop and go traffic.

Last trip I took I got over 28mpg on some stretches, overall average was 26 I think. 460 miles to one tank whereas I normally get just over 300 in mixed driving. Modes were sport S and normal. Lots of cruise control, but I was running it 75-80-85mph (usually go 5 over anywhere, some roads in Texas are fast).

The most important factors for economy during highway driving is drag coefficient, vehicle weight, and gearing. My '13 has a decently tall 6th gear although newer models with the 8 speed may be higher. cD isn't bad on the F Sport either.

 

Are you seriously pulling 38-40 on those Florida flats? It seems maybe a typo 10mpg higher than reality....

 

Yeah, even 28 to 30 is pushing it.

 

The detuned & more efficient hybrid can do up to 40 mpg @ a constant speed of 55 mph on perfectly flat or on slightly downward sloping roads. That's really in all ideal conditions though. It's very difficult to maintain that mpg number.

@RomanTPA - Please post a video of your GS350 getting 38-40 mpg on the highway over a period of time. Or take a picture of your efficiency from your route on the navigation screen.

~ Im2bz2p345

 

The best I've seen is a trip average of 31mpg (about 530 miles) - cruise control set to 70. Most of the driving on flat open highways. Got the same on a different trip (about 200 miles) - similar conditions, so I know the car can do it.

 

Some of these numbers seem low to me. AWD versus RWD difference?

My setup: 2013 Lexus GS 350 F-Sport RWD 6 Transmission. City is 21. On average with a 30/70 City/Hwy mix I'm getting 23.5. HWY is 27. My last all highway trip ended up with 28MPG. I have some fun when I drive too.

 

I have never gotten below 19mpg in mixed driving. Usually close to 25 if I run a full tank out on the highway.

 

I was thinking the same thing. I suppose the way one drives is a big difference, but I posted in another thread looking for reasons for variations, and I think tire size could make a difference (going from 18" to 19") for example, getting low rolling resistance tires, and summer vs winter gas as simple reasons.

I am going to post in the hybrid thread, but so far in about 1000 miles, my wife has been averaging 30mpg. Considering the EPA range is 29 city, 34 highway, I suppose that is not bad but I have been trying really hard to see the high end of that range, and I have not been able to achieve it, but mind you, I can't drive 55 (in Sammy Hagar voice), so perhaps that is the reason, lol

For some with really low MPG, that is really odd, my Ranger Rover, all 6000lb and all, with a 5 liter supercharger averages 17-18mpg city/highway, probably 80% highway. I'm not going to say no way should a GS 350 be worse than that, but, no way should a GS 350 be worst than that.