I hear you loud and clear Mr. NotFasty. It's been very cold here as well. And so early in the season. We even had a dusting of snow on a couple of occasions as well. I live in a suburb about 45 minutes north of Detroit not far from the FCA and AUDI Headquarters in Michigan. So far in spite of the cold, I am holding steady at 15 MPG in city driving. I am wondering if it is going to last though????
Perhaps you are right, those in warmer climates are reaping the benefits of better mileage then we do. Lucky in both the weather and MPG.......

 

I'd have the O2 sensors checked. You didn't say how many miles are on it, but if they're high, you may have one or more becoming 'lazy', but not yet throwing a code. I've had that happen once, though not on either LS-L I've had (an '08 and '12).

FWIW, my 65% highway commute (and it's 80-90 MPH...Texas), returns about 23 via the car's computations, and 22.3 using pump gallons and mileage.

I've seen as high as 30, again, Texas, Houston to Fort Worth, A/C on, 85 MPH. This is in an "L", too, which weighs a bit more, though may be slightly more aerodynamic because of the extended length. Gotta love a 600 mile range (if you're careful).

If I see sub-19 MPG, there's a problem, or I've been hammering on it around town.

 

What he said 👆🏻

 

I'm going to have the O2 sensors checked, thanks. Has about 28,000 miles, few of them at 80+ mph, about 80% of my driving is at city speeds.

 

I generally use "no name" gasoline at a military base (they say it has the same additives as a name brand, is in fact obtained from a name brand supplier, and I believe it). I did try a full tank of the top tier gas from Shell or Chevron for 200 miles and mpg was the same. .

 

I get the miles driven from the Trip meter, gallons from the fuel pump, then divide. (Pumps are checked for accuracy by local authority, there can be virtually no difference between them.) I usually fill up about every 200 miles. 13.4 average for some 28,000 miles is the number shown on the display.

 

I have an 07 LWB with almost 120000 miles and I am regularly seeing 17-18 MPG on each tank.

The car has always had a good service record and when I got it I ran some high mileage Seafoam and had the transmission service done and I always use Costco 91 octane. I saw a noticeable increase in mileage after the transmission service was done by Sarno Motors in Huntington Beach. I plan on getting the plugs changed soon and I would be super happy to see 20 MPG like some other members here.

I drive all the time for work and do a good mix of city and highway driving. When I take long hauls on the highway then I have seen 19 and 20+ MPG on that tank until I drive around town for 10 miles or so. Either way I look forward to driving around town in total comfort and class!

 

Something seems wrong. My 08 gets high 20’s on the highway. Change the plugs?

 

I get 14-16mpg according to Fuelly with 80-90% city driving and daily trips to redline in M mode.