this is interesting, even though a small sample, seems reliable.

http://www.fuelly.com/car/lexus/ls430

I have only about 30k tracked, but my overall is 19.3 mpg, again in the ballpark. I think it is truly not bad for a 2000 designed 8 cyl. engine--that's 19 y.o. technology.

To me, there is a direct correlation between avg mph and avg mpgs. The lower the avg mph, the lower the avg mpgs. Mine tends to be in the ballpark of 20-23 mph which is low, indicative of a lot of stop and go suburban and urban driving. Very little highway.

 

for V8 i think is not bad at all with average of 20MPG.
my M4 is 18.5MPG
myS2000 is 22.5MPG

 

True, I never understood why the EPA rating was I think 16/23? The only time my car sees 16 is when my wife drives. And I get 27-28 highway if the car is allowed to cruise at about 70 mph for an extended range.

And that's not bad for your M4. My 335i used to be 21.7 under the same circumstances (identical commute over 8 years) as the LS430's 19.x But as of late my 335i has dipped into the 19's too. I think it needs a walnut blast likely my intake valves are caked. My 1998 Maxima was the same 21.7. Imagine the 1998 had 190 HP and 205 ft. lbs., and the 2007 300 HP and 300 ft. lbs., identical on the fuel...

 

I haven't put many miles on my new 2006 (maybe 500), but I was curious about the gas mileage that I would get with this car. I traded in a 2001 Highlander, so I figured it wouldn't take much to beat what I had. Nonetheless, I do a fair amount of highway driving, and I was hoping that I'd settle in around 25-27, as multiple owners said that they were getting high 20's on the highway. So far, I'd say about 65-70% of my driving has been on the highway and my dash says that my tank avg have been 22.7 and 23.1. I could probably eek out a little more, but sometimes it sure is tempting to step on the gas just to feel how smooth it accelerates. My previous Highlander had some pickup, but you definitely noticed that you were trying to accelerate.

 

 

A large V8 vehicle is not going to get good gas milage in stop and go city driving. On the highway at the speed limit I get just under 30 mpg .....

 

My short trip mode is power on now after a couple of years of ownership. I like the throttle response that traffic driving requires. Like Boca...15mpg or thereabouts.

On a trip the switch gets set on econ. Cruise on at 70 to 80 (texas) I get 25 to 28 at the pump depending on winds.

Just a great used car that, imo, looks terrific without shouting.

 

Here's mine which covers March 2017 through Sept. 2018

http://www.fuelly.com/car/lexus/ls43.../n84434/596138

54,382 miles and over $6,000 dollars spent on gas in 18 months, which is why I had to sell it....

 

2005 LS 430:
Over the last 12 months, 5,500 miles mix of city and highway, 23.6 average mpg. At a steady state of 50-55 mph on level ground the car gets about 31. My best tank so far: 29 mpg. Worst tank: 20.5. Highway speed limits around where I live are 50-60.

My daily driver, 2013 VW Passat TDI, gets about double the mpg.

 

i'm in nyc drive between queens and LI, average so far 16mpg

 

14-18 country driving very hilly when I am in a city like Albany I get 16-19, the car is stored for the winter time so that reflects on the mileage also. My rx330 gets 17-20 for reference it is driven year round.

 

18.5-19 on a backroads commute of hills to go up and down with some stoplights, about 26 on the highway.

I believe the aerodynamic drag coefficient is .25, which is fantastic.

 

The 0.25 Cd only applies to the UL (which has air suspension), which lowers the height of the car by approximately an inch at driving speed.

 

From Wikipedia:
The body was also more aerodynamic than previous LS sedans (Cd 0.26; 0.25 with air suspension), and was the product of wind tunnel testing at facilities used for Shinkansen bullet train development.

I think this is a big reason why 430 can get ~28mpg while cruising at 70mph.

 

21 mpg around our little town in mixed driving. 26-27 out on the highway on long trips.