I'm driving my 4th car. The first was a Datsun, the last three have been Toyota Corollas. The first two I got used, and they both lived to be 14. The third was new, and it lived to 15 years and 1 week until it was killed in a freak accident, days after I spent quite a bit of money on it.
Quite obviously, I do favor the Corollas. With each new car, there are new things that I'm glad to have, but there are also disappointments. On the current car I still cannot shut off the daytime driver lights, but I have plans.
When I get new cars I do make sure some of my larger friends will be able to fit in them with relative comfort and the Corollas have always passed.
My last car was getting about 40 mpg until it turned A Certain Age, and I replaced the spark plugs. Concurrent with that, was the national speed limit being raised from 55 to 70. At that point it became closer to 30 mpg.
I have gotten over 40 mpg on the current car -- while driving out to Toronto on the 401, and not exceeding 100 kph. I really like it when a friend drives my car, because he gets even better mileages. On a recent trip through the mountains of PA, with 3 people and all their gear he got nearly 40 mpg.
I've started an experiment. I'm trying to not exceed 55 mph on the highway. It's difficult. I enjoy traveling fast. I don't think it's safe to travel more slowly than most of the people on the road, and I don't think it's polite either. While I may logically think "gosh, I don't want that person to be driving faster than they're comfortable doing", there's an inner voice that for all I know might be programming into my genes that is saying "For crying out LOUD! There's NO bloody REASON to be moving at 35 mph on a perfectly straight road with no cross streets when it's daytime, when the sun isn't in your eyes, and when the speed limit is 55! Get off the road! Learn to drive! It's the one on the right!"
I'm also trying to travel at legal speeds in the city rather than travelling with traffic at a safe and prudent speed for the conditions (weather, road, cycle, and pedestrian). It's very annoying because it seems that the lights are timed for about 3-7 over, so I'm arriving late not only because I am moving a little more slowly, but because I'm waiting at every controlled intersection.
Spouse just got a new car, a hybrid, and he gets mileages I can't even dream of.
Not that I'm competitive or anything.
The friend who gets good mileages out of my car has recently been borrowing a Hyundai Sonata. I grumble and "hmph" a lot, because he is getting on the order of 50 mpg, at least on the highway. He is getting the sort of range the spouse gets on a tank the size of the one in my car. And is more comfortable. And fits better. And can see better. AND he can turn the lights off. I don't know what it costs, I don't know if the car comes in stick, or whether it's as good when it does, but, but, but...
Not that I'm ... competitive... or anything.
Although if history is any indicator, I'll be driving my current (2009 model) until 2020-something and the world will have changed.
But I'll confess that there is a portion of me that would find it appealing to own a car that was significantly cheaper than the spouse's that got better mileage than his does.