So the plug-in model for the 6th generation Rav4 not only gets the 6th generation Toyota hybrid system, it also gets noticeable updates to the A25A engine itself. On the plug-in model the A25A engine block and cylinder head have been strengthened, and the engine girdle has also been strengthened. This is the first time we see major improvements to a TNGA gas engine. The T24 doesn't really count as that's just basically an A25A modified for turbo application. All of these updates to the A25A on the plug-in model supposedly significantly improve the noise, vibration and harshness of the gas engine part of the plug-in system.
I personally think this is unfair and disappointing that the regular hybrid models also didn't get these updates to the A25A gas engine. TNGA engines, transmissions and platforms have been quite disappointing in many ways since coming to market and haven't come close to living up to the hype that Toyota had when it unveiled its TNGA engines, transmissions and platforms.
All TNGA gas engines desperately need updates in a variety of categories, and now that we get some updates to the A25A, it is limited right now exclusively to the 6th generation Rav4 plug-in only. We don't even have an idea of if or when these updates will come to any other Toyota or Lexus models using the A25A engine.
I am glad though that by going all hybrid with the new Rav4 Toyota has eliminated the 8 speed auto transmission. The various 8 speed auto transmissions that Toyota and Lexus use are some of the worst transmissions in Toyota history. Toyota needs to desperately remove all of these 8 speed auto transmissions out of their lineup. The only one that I can't speak to is the 8 speed GR auto transmission as that's the only one I haven't driven amongst all of the 8 speeds Toyota and Lexus are using.