My avg shows 18mpg on my 350. My loander 250 showed 23mpg on its display.

 

I'm getting a consistent 24-25 mpg with a combination of probably 80% highway (spirited driving mode) and 20% city driving. I've found the mpg computer is dead accurate when I compare it to mpg I get with a pocket calculator after filling up. But to really get an accurate figure you should always do the math after a fillup and not rely on the trip computer as these can vary wildly.

Only have 2000 miles on the car so perhaps it'll go up a bit. I'm satisfied with this mpg.

This thread shows a huge variation in mpg which is not surprising as driving style greatly affects the efficiency of any car. I imagine there are some real leadfoots here who tear from stoplight to stoplight and mileage will suffer greatly in this kind of driving.

 

I don't have a heavy foot..dunno why my mileage is so bad, my s2000 gets bout 2 miles better than my IS. I always calculate my mileage manually, not by the trip computer.

 

My mileage is horrible as well. I'm getting about 307 in the past 2-3 fillups with a tank avg. of 21-23 mpg.

I REALLY want my mileage to go up to 345 like it was rolling out of the lot!!!

 

I know I may get flamed by some about this, but I'm a big believer in Techroline (Chevron's fuel injector cleaner). I made it a standard 5K maintenance item to run the tank nearly empty, add a big bottle of Techron to a full tank of Chevron Super Unleaded, and run it till it's nearly empty again.

I saw very significant results on a used car that I purchased in Texas and drove to Virginia years ago. I averaged about 24 MPG on the 1st tank of gas (on the interstate), added the Techron for the 2nd and 3rd tanks, and watched the mileage climb to 29 MPG over the next 800miles. I enjoyed years of 30+ MPG highway driving in that car afterwards.

 

I consistently average 18 city/28 highway

 

Getting only 21-22 MPG, but was told it's supposed to get better after the break in period, which should be end of this week

 

Are you guys reading off of tank avg or avg? I read off the tank avg because I find it more current. But I am getting 17mpg and I have a light foot. I do 100% city but that doesnt match up to many of you who are getting 20+ on the city. I see a couple guys who are having the same issues as I am. Anyone knowledgeable enough to figure this one out?

 

Do you do lots of short trips? I've found that short trips really hurt mileage, especially in cold weather.

 

City mileage will vary a LOT depending on the type of city driving. Inner-city driving in big cities will cause terrible mileage due to traffic jams, low speed limits, and tons of stop lights, but suburbia driving includes some highway and longer stretches between stop lights.

 

I went from having about 275-280 miles on a full tank to 307-311 in about a month. Hoping to hit the 350 mark by the end of the year.

btw, this is sort of off topic, but I heard something about resetting the setting that makes your car learn how you drive...anyone know how to?

 

I would guess that most of that difference in mileage is due to the change in temperature. It is getting cool enough in Texas that the A/C isn't working hard, yet warm enough that the engine runs efficiently. Once winter hits, your mileage will likely start to drop again. Cold gasoline doesn't atomize as well as warm gas.

 

i commute in heavy northern va (DC metro) traffic. I avg 17-18 mpg. On the highway i can get up to 33mpg...going downhill i can get 93 mpg, wink wink

 

AC on or off accounts for 2mpg.
I'm fully broken in at almost 16k miles and lifetime mileage of 30.1 mpg on my 250 M/T. Mostly highway miles, but at 75mph. At 70mph I consistantly will do 36-38mpg. If I lock the cruise at 65, I do 42mpg all flat roads.

 

what kind of gas do you guys put?.... with my IS250, I get about 22mpg avg. with Shell or Chevron dam.... im lucky to get 24-25 avg.