rpm

I have seen some threads that indicate some similar symptoms. But recently (around 12 months and 25k miles) my Bronco Badlands 2.7L began to roughly idle (noticeable shake in steering wheel and seats) between 800-1,100 rpm (the cold start range for me). After it warms up and lowers to 500-600...

So... I starting looking at tires I could put on my Bronco when it eventually (hopefully) gets here next year. I'm still debating between the Black Diamond and Badlands, which have different axle ratios. I was doing some math to figure out what the engine RPM would be at specific tire sizes &...