With the exception of the bad fuel economy that I am getting with my DX motor in the higher gears, I have to say that my biggest gripe about the HF transmission is poor around-town gearing. First just feels WAY to tall. And the other gears are just too widely spaced. This has me wondering whether it might be better to swap fifth gear from an HF into a DX transmission. This way, you keep the better around-town gearing of gears 1-4 in the DX transmission, along with a fifth gear that is similar to fourth in the HF (60MPH=2500RPM). Has anyone tried this combination? And has anyone tried this with a D15Z1? I don't know what the mileage penalty might be with a D15Z1 vs an HF transmission. But it seems like this switch might be worth it for a transmission that is more usable in real-world driving.