Had mine since new and NEVER got the on the widow sticker advertised 27mpg/hwy. Even babying it the most I ever got was 25. Thought the window sticker rated mpg was conservatively figured and in reality the mpg /was slightly higher.

What'* your altitude, and what octane fuel do you normally run?

If you're getting 25 mpg, that'* probably the best you'll ever get which is pretty darn good. Those mpg ratings on the factory sticker are derived from very strict, controlled test standards. Normal every day driving (highway) will not support getting 27 mpg, but 25 is real close.

Here'* a little something I read on EPA ratings in an article in Motortrend, about a roadtest comparison with the gas-electric hybrids. The information about how the EPA does the testing is the same for regular cars. Here'* some quotes from the article:

"...those numbers are generated in the comfort of a test cell, and real people--even fuel-economy nuts driving with the proverbial egg on the accelerator--have been largely unable to match them out in the cold, cruel world. Informal Internet poling among hybrid user groups suggests actual mileage averages of around 40 for the Civic, the mid-40s for the Prius, and 50ish for the Insight. Our own one-year hybrid fuel-economy averages have been even lower. Why is this?

The EPA test procedure is grossly out of date. It was designed around the cars, test equipment, and traffic flow of the carburetor age (late 1960s) and chiseled in granite by 1975. The 11-mile city test includes 23 stops, with a maximum speed of 56 mph, an average speed of 20 mph, and about five minutes of idling. The 10-mile highway test averages 48 mph, peaks at 60 mph, and includes no intermediate stops and minimal idling. Correction factors were introduced once, in 1985, reducing the city figure by 10 percent and the highway figure by 22 percent in an attempt to reflect real-world driving."

So as you can see, the EPA rated numbers on the window stickers are considerably higher than what you'll experience in the real world. Sucks, I know. I've been wondering how some of these guys are pulling out 31mpg trips out of their SSEi'* and I can't get over 23 on average.

If you go by the DIC'* average reading, it takes into account warm-ups and idling that really kills the mileage average.
With my short trips I rarely average better than 15 mpg.....but have gotten up to 30 mpg!

If you run with a warm engine steady state on the highway at 55 mph on level ground, reset your DIC and then see what your average is after a short time.
It will be 30 mpg.

I've driven a 200 mile trip at 80-85 MPH the whole way and averaged around 32 MPG in our bone stock 00' SSEi. I consisently get right around 28 MPG in my Riviera as well driving on back roads at around 55-65 MPH.

Being in CO, I don't think he'll have as easy of a time getting our good mileage. That'* why I asked about the elevation.

...moved here from STL at sea level and the best I EVER got was 25.1 per my DIC and calculation. Like to see credible proof from guys that claim to get 32 mpg, though.

I just got in from a 650 mile trip in 8 hours, highway was bare and the moon was almost full. Large familly of 4, trunk loaded, returning from a wedding.
I used 112 Litres of 94 octane (Chevron). 24.7 Imperial Gallons or 29.47 US Gallons.

Thats 26.3 Miles Per Imperial Gallon
or 22 Miles Per US Gallon
at an average speed of just over 80 mph

If your willing to pay my Visa bill you will see the fuel amounts and times when fuel purchased to confirm