What is your RPM when you are going 55 mph?
Hi racebo! I couldn't find anyone to venture a thought in that on the web. That's going to be the type of tech/spec question that you are only likely to get from your Ford Service Manager. You could try the local library where they'll likely have a Chilton's for your Probe. I just don't think that specific answer will be there ... With gearing ratios there is a mathematical answer to that but it's out of my league. Good luck!
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