[Mageeacres]

Jon, you were reading my mind, looking for the sweet spot in the power curve and then adjust accordingly. When these coaches were made it was when 55 mph was the federal highway speed limit. So naturally 50 to 55 was normal. I found a speed ratio chart in with the original paperwork from Newell. I’ll post the photo. It lists all available ratios and their rpms for both 22.5 and 24.5 wheels. It looks like they (Newell) had marked which ratio to use. It was the 3.70. Now to verify... also I’m trying to get a response from caterpillar technical division to verify what rpm they recommend for the current configuration at 65 mph. I’ll definitely post the results for you also. Also waiting on a callback from a transmission expert and a OTR supplier for input into this equation. ....