Originally Posted by Chuck33079

Personally, I try to keep it above 2500 rpm, and at 55 I'm usually in 5th. Granted, I'm on the freeway for 5 miles on the way to work, so I'm not really cruising for long distances. If I were racking up a lot of highway miles, I'd be in 6th at 55 and not worry about it. Just make sure you downshift to pass. Lugging an engine at very low rpm is not great for it.