My dad gifted me a 1986 F250 a couple months ago. It's a diesel with a 6.9liter V8, no turbo. A massive motor, but still gets 18-20mpg. It's paid for itself a few times over already simply by allowing me the ability to get free stuff on Craigslist, (including $700 worth of free paving stones that weighed over 1000lbs!) It has 264,000 miles. It's easily worth the $20/mo it costs to add to my insurance.
I recently, 2 months ago, bought a 1997 Honda Civic 2 door coupe with 290k miles on it, from the original owner. I drove it home to Seattle from DC after a friends wedding. It now has 294,200 miles. A few times a month, I have to drive 230miles round trip up to my home office for sales meetings and client meetings. This car gets 37-44mpg, or roughly 1.8* better fuel economy than my Ford Taurus that I drive my clients around in. If I drive separately, I take the Civic. Last week I drove it 580 miles in two days. It saved me $25 in fuel, wear and tear on my nicer car, and easily paid me back the $22/mo I pay to add it to my insurance.