So I Googled it that the 06-2011 GS350 S190 is supposed to have 19/26mpg so average of 22mpg but mine is much lower than that. I drive both freeway and streets. AC is never run, windows mostly up. Tires are new with 33psi. I dont drive all crazy with full throttle. That said, I only get about 16.2mpg. How did I calculate you ask? Every time I fell up on empty, I reset my travel meter back to 0. Then I calculate how may gallons I filled up, most of the time around 17 gallons (max capacity being 18.8 gal). So around 260 miles on the odometer is when the gas light comes on and by the time I pushed it to 275 miles, the gas meter is noticeably below the Empty line. I pull over to the gas station and it filled it 17 gallons, with I'm assuming 1.8 gal left in the tank so 275miles/17 gal filled= roughly 16.2mpg. How many mpg does your S190 get? What can be the problem that it's burning so much gas? Thank you

 

I have an 09 GS350 AWD. I get about 18 mpgs in daily driving (trans set to norm) and about 23-24 mpgs on the hwy running about 80 mph with the cruise control engaged.

 

I get 22 mpg, mix driving, on my 300. Have you done a tune-up?

 

Scan for codes, if none, disconnect your neg. battery terminal for a ~ 15 minutes, reconnect and then go for a fairly long drive on the freeway observing your mpg - try it!

 

2006 gs300 AWD anywhere from 17 (in winter all city) to 23 (every other season with mixed. 2008 gs350 RWD, usually average 20ish in the city and 23-34 mixed, with up to 30-32 straight highway

 

Reading those mpg figures makes me jealous, hehe. I got average 13mpg only city driving with medium traffic and 15mpg mixed city and highway that's in my GS300 RWD. My driving is not slow I like making my kitty roar from time to time.
Try checking your oxygen sensor, sometimes they are to blame. Also make sure you got your filters and fluids serviced up (diff, atf, engine oil) also try cleaning MAF sensor and check your spark plugs. Also what tires are you using? Tires can cause mpg drop, since I use Pirelli P Zero's which are sticky! But I prefer safety over mpg when it comes to tires.
I hope reading my figures makes you feel better. Good luck!

 

We've only had "Lucky" one month. We filled it up and decided to keep an eye on its mileage today. We drove mostly on highways, but a fair amount through stop and go traffic, and we still got 26.7 mpg. Not bad for a 2 ton car with a 302 HP motor and AWD.





We got 19.3 mpg for our first tank of gas; we drove 247 miles and burned 12.83 gallons of gas. That was probably 70% city traffic and 30% highway. We will be taking "Lucky" on its first little trip on Monday. I will top off the tank right before we stop then fill up right as we finish the trip. I am hoping to best 30 mpg.

 

This topic came just in time if me researching my drop in MPG. I have the GS430 V8 model and I used to average 25-27 MPG in California and the North Eastern States. Since I moved to Southern Texas I noticed my Average MPG is now 18.5-21.9, I've done a complete tune up, New tires and Alignment, New plugs and Coils, complete suspension over haul. Changed O2 sensors a year ago. The only suspects to consider is the Air Fuel Sensor or just plain old ****y gas packing that I purchase from Exxon and Shell.

 

gs450h.
Worst I've gotten is 21, flooring it a bit too often. I have to maintain way above 100mph constant on the highway to reach this kind of consumption during steady state cruise... forget about it
Current tank is 29-30 - a bit of highway, a lot of main city roads (maintaining constant speed is not very easy), some small city streets, uphill village.
Best - I think 39, rural road, cruise control, ~43mph.
Usual highway - 30 to 33 at 70mph.
City - if it's lots of stop and go + jams, can get worse than 23. Usual 25-26.

AC is just about always on, summers are pilot sport 4 245/40/18 at 36/38psi front/rear (possibly a bit much, but I'm still following the manual on this).

Fuel is 95RON, about the equivalent of US 91 premium I think. No benefit noted when running on 98 or 100.

 

thats at 110 km/h for 3 hrs

 

Believe it or not my GS460 with almost 140 averages 30.9 on the high way on cruise if I keep it between 70/75. I keep my foot in it during street driving to notice what I get there.

 

First fill up in my 2008 AWD after a tank that was 80% highway. 32.4 mpg. Like...wow! I drive to maximize fuel efficiency; I only use full power when I absolutely need it.

But still...wow.

 

The best I've gotten is 8.5 L/100km, from Toronto to Buffalo with mostly 130-135 in on winter tires in March.

 

I drive gs450h 2008, highway best so far was 6.8, on average 7.5 on highway, in town it's around 9-10 litres per 100 km. I'm in Europe, idk if we have different fuel here. I always go for the 98th.
Where I live we don't have autobahns, speed limit is 110km/h. Well... 120 :P

 

This is my "record" lol with a full Magnaflow exhaust and removed cat and resonator on my 2006 GS430 driving very subtle and pressing softly until I got to freeway speeds. Normally I'm in the 15-16mpg range.