As someone would undoubtedly have pointed out, it's actually a little more complicated than that. For an FAA PPL holder to fly a Malibu they would need to have received training (and had their logbooks endorsed) in respect of pressurised aircraft, retractable gear etc.
Well, allright, let's put that last bit of Air Law relevant to this on the table as well then. In JAA-land, within the SEP(A) class rating, there is an additional *legal* requirement to get differences training from a suitably qualified instructor, and an endorsement from same, in case of:
- Variable Pitch (VP) propellor
- Retractable undercarriage
- Turbo/supercharged engines
- Cabin pressurisation
- Tailwheel undercarriage
The advantage of this is that it stays completely within the class rating. So once you've had your differences training to fly an aircraft with a tailwheel configuration, you're legal to fly any tailwheel aircraft within the SEP(A) class without any further training.
Again, whether that's wise is another matter.
Note that there are a few anomalies here, where modern technology has progressed beyond what the law currently regulates. As an example, I am checked out on the DA-40 TDI and the Robin DR200-135CDI. Both have a Thielert turbo diesel engine with a constant speed propellor. But both the turbo (wastegate) and the constant speed governor are controlled by one lever. In fact, the lever just inputs the desired performance to the FADEC/ECU computer, who regulates throttle, fuel flow, RPM, manifold pressure and everything, even taking into account ambient air pressure and temperature. Technically, I'm now legal to fly any turbocharged and VP propellor within the SEP(A) class, but it would be extremely unwise for me to do so. And I don't think that's what the law intended to achieve either. Perhaps there should be a separate "FADEC" differences training requirement, separate from the others.
By the same token, you could also make an argument for legally required differences training with regards to glass cockpits like the G1000.