I have not purchased my next car as of yet, but my research here and on other forums has moved the Genesis to the top of my list. I'm going out to test drive the V6 and V8 versions this afternoon and would welcome the opinion of owners regarding this issue. I live in Manhattan and garage my vehicle at a nearby commercial garage. The 50 or more cars are constantly started and stopped briefly as the two-story puzzle game of getting access to particular cars is played. The facility is underground so it isn't bitter cold but certainly does get chilly in the winter. Given this fact of city life, am I wiser to focus on the V6 to avoid potential problems? I scanned the V6 threads and don't find any similar cold start issues. I'd be happy to run synthetic oil but I'm not sure it would be enough to prevent issues. Thanks in advance for your opinions!
Some will disagree with my post, but here goes:
This particular problem has only been reported on the 4.6 Tau engine (not the Genesis 3.8 Lambda V6). The Hyundai V6 Lambda engine has been around for a fair number of years in previous Hyundai's and Kia's (although some version had smaller displacement), and most likely the major kinks have been worked out. As you are probably aware the 4.6 Tau was new for 2009 model year and not sure if it has been modified since then (except for the 5.0 version). Not sure if any 2012 4.6 or 5.0 owners have reported this problem, but obviously there have been reports of this problem from early Genesis model years.
I know this has been stated before, but it appears that the problem is that when the 4.6 engine is cold started and shut off before it warms up, then certain internal engine components are apparently not returned to the correct position for a restart, and a misfire occurs. Not sure if this is values, lifters, or what, but that is what has been reported, and it may not be so easy for Hyundai to fix existing engines. But if you make sure that engine is completely warmed up before you shut it off (and don't forget), then you probably will not have any issues.
My personal guess is that the engine relies on gravity for these engine components to return to correct position after shut off, since it seems to only be a problem with shutting off the engine before it warms up, but also some who parked their car on steep slopes also reported the problem.
Since this problem does not happen on the 3.8 V6, if you find 333 HP suitable after a test drive, it should be fine (although the GDI feature of the 3.8 L is new for 2012). The worst I have heard about with the 2012 3.8 and 5.0 is some minor GDI noise that cannot be heard from inside the car, and maybe some occasional rough idle at cold startup (but no misfires). I have not had any problems with my 2009 V6, and I do use Mobil 1 0W-30 (Mobil 1 0W-20, or Mobil 1 5w-20 probably better for cooler climates). Other quality brand synthetics should also work well.
If you absolutely want a V8, I would probably wait for the Genesis (non R-Spec) 5.0 that is now on the Hyundai website. Not sure how many are available at dealers yet. The reason I say that is they did obviously make some changes to the internals of the 4.6 to make it a 5.0, and maybe they had a chance to fix this problem in the process. It appears likely that the 4.6 engine will no longer be offered when the Genesis 5.0 is shipping in quantity (but not 100% sure about that).
