When I bought my truck I had a 5 year loan but went ahead and paid the 4 year monthly loan rate (they didn't penalize for early pay off, I checked). I figured I could pay it off in 4 but if something happened and I needed to pay less, than I could fall back to the 5 year payments and still be OK. It worked out well for me; I made 4 year payments up until I was off of work for 5 months and then I switched to the 5 year.
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