I dropped my 09 g37x off at the dealer this morning for service and was given a 2011 g37x loaner. On the road the car felt a little different. Acceleration seemed smoother, quieter, and more refined. My 09 seems harsher and louder. Nothing that tells me there is a problem with the car but it seems more like a muscle car and less like the a luxury car.

Are there any differences under the hood? has anyone noticed this too? Is maybe somethign wrong with my car? Or I am just a little crazy?

 

There should not be. Maybe ECU tuning, but nothing else that I am aware of.

 

no, I had the same experience, I think Infiniti made some suspension geometry adjustments maybe, and possibly more soundproofing, but there are no engine or tranny differences EXCEPT that the new loaner probably had a version of the new tranny and ECU tune, which does seem to mitigate the infamous 'throttle lag' which is a combo platter of a number of things (ecu tuning, tranny tuning, and lockup rpm point for the torque convertor) - I think mine had a different ECU and TCU tune. But it did not feel as good on the freeway at high speeds, was 'dartier' than my 09. But a little quieter and it did feel more refined around town.

 

some of the aero was changed on the front end, but as said nothing under the hood except for a better tranny ecu.