https://www.clublexus.com/forums/sho...t=tank+mileage
Another thread that has a lot of input on gas mileage.

IS350 here. I have improved ever since I put on 20s on my car (I tend to drive carefully and softer now) ~ 260 a tank. Compared to 200-210 when stock.

 

DAMN WTF.... why when i fill up it tells me 315 miles till empty and everyone else is getting around 415 to empty... is this $3.51 a gallon gas so cheap??

also, mia IS250 i refill because on my old car i blew the fuel pump by leaving it to empty all the time... i dont want it to happen again

 

Wow, some of you guys are getting some great gas mileage. Looks like I will be doing quite a bit better then my G35 coupe.

Lips

 

I'm getting 310-330 in my 350.

 

85% - 90% highway driving.

Tank average ends between 27.5 mpg and 28.5 mpg.

If I let the miles left before running out of gas go to zero I usally get 410 to 430 per tank.

In that tankfull I will gun it 4-5 times.

Full tank lasts me 4-5 days.

 

I don't feel so bad about 340-360 per tank. Also, I drive till it goes to zero... there is always at lease a 1 gallon reserve BUT it seems in Lexus's case its 2 gallons because when I fill up I can only get around 15-16 gallons or so.

Oh yeah I do a lot of city driving - 80%; highway - 20%. One last detail... I have a GS350. lol, 3GS section is boring.

 

I normally fill up once I see the fuel light go off, but noticed that I was only filling about 14 to 14.5 gallons each time. Knowing that my tank was good for 17 gallons I asked my local Tech about how conservative the fuel gauge is on our cars and he said "Very." Even when I've run it to "empty" and less than 1 mile est. on the meter I've only had to fill about 15.5 gallons. It scares me a little to go passed the empty line and just trust that there's another 1.5-2 gallons of gas in there, but it's good to know that if I'm ever almost out of gas I don't need to panic for a bit.

Having said that, I'm getting about 19.7 mpg lifetime on my 350 and 280-310 miles per tank. I drive this thing pretty hard however normally cruising at about 80-90 mph to work in the morning and then getting stuck in gridlock going back home. How in the world is everyone else in a 350 getting such high mileage?! I can't imagine being able to drive this thing any slower without feeling like I should have just gotten another car. Honestly I think of it like buying a porche only to drive it at 60mph....

 

I'm only getting about 310 per tank but then again I've only filled it up 3 times so far. Once new, Once at 300 miles and now at 610 on the odo. At 1k interval I will be switching to Castrol Syntec 5W-30 and hopefully it will improve some. I'd use Silkolene or Motul but this engine uses 7 qts of oil for an oil change.

-Joe

 

Usually about 375 per tank, 80/20 highway. I got about 420 miles on 15 gallons once, 95% highway, 5% stop-and-go.

 

just over 300 miles

 

i get about 380 to 410ish.

on long road trips over 400.

 

Does anyone know if the "range" on the meter includes the reserve? Or just til the light goes on? Thanks