How do you measure
I have found many people report mileage differently. You are probably comparing apples to oranges in this thread.
Do any of the T-Birds give instant gas mileage on the dash? Mine does not. So my calculations require me to fill up the tank, drive a long ways (rarely a consistent style) fill up again, and do the math. And it makes a difference how level the ground was when I filled up both times. So it is difficult to get a good datapoint.
Also, are we talking ragtop up,
hard top, or top down. This makes a difference to gas mileage.
Have you checked your Spedometer against a GPS? My speedometer reads a bit high. Speed affects gas mileage. Someone mentioned their mileage driving between 65 and 75. I guarantee you, your mileage is not the same at 65 as it is at 75.
My commute to work is 2 miles, so the engine hardly has time to get to a good operating temperature before I am there. I live in a small town where it is ten minutes to the other side of town. I drive agressively. So if I go through a tank and do not leave town, I get bad mileage.
I have measured as low as 16.
When I travel, I set the cruise on the speed limit (I don't push it, and I don't waste time/energy watching for or worrying about police) and drive a very constant speed. This contributes to good mileage.
On a 5 hour roadtrip, I have gotten 27 with the top down, over flatlands (Mississippi delta mostly), and keeping the speed right at 65. At lower speeds, I am sure I can do better than that.
On a longer roadtrip with the top down, I averaged 25, but it was either through Arkansas mountains or 70MPH interstate speeds.
Most
gas tanks are a mix of highway and city driving. This puts my average mileage closer to 20 or 22. But that mix only has meaning for me.
Based on what I know about differences between the 2002 and 2003+ Thunderbird, I would not expect any measurable gas mileage difference between them. The 03+ engine is more powerful, but most of that gain is at the top of its RPM band. To see a difference, you need to spend enough time in this RPM band to make a difference. If there is a difference in the lower RPM bands, I would expect the 2003 to have better mileage than the 2002. Not worse.
Your mileage may vary.
