My fiancée has a 1994 Toyota Corolla that is on its last legs (or tires, or whatever) with almost 330,000 miles on it. We're planning to get rid of it when it either becomes disabled or we take it in for regular service and they find something urgent that would cost more to fix than the value of the car. I have a 2006 Camry that is in great shape with a bit under 185,000 miles on it that we also hope to keep until one of the two aforementioned conditions befalls it.
One of us drives 7 miles each way to work, mostly on city streets and at stoplights but with some brief time at highway speeds (60+ mph). The other drives 20 miles each way but spends 80% or more of the time at 60+ mph.
We live in the Puget Sound region, but not too close to saltwater. That means wet but not too cold in the spring, winter, and fall; and mostly dry and mild to warm in the summer.
To maximize the longevity of each vehicle, which route should we use each one on (or should we alternate)?