Hello,
I don't post often on the forums, but didn't see anything else posted on this topic and was curious if anybody else has noticed the same thing. In relatively cold weather (< 50 degrees for here in Florida), the 4.6 in my 2009 Genesis feels much more responsive (particularly in the mid-range) than in 70+ degree weather. I understand the physics of it with the air being more dense, but the difference with this car is much more pronounced than any car I've ever owned.
For those of you that switch back and forth between regular and premium on the 4.6, the power curve would look something like this:
Best - Premium fuel and cold weather
Very Good - Regular fuel and cold weather
Very Good - Premium fuel and warm weather
OK - Regular fuel and warm weather
My guess is that Hyundai is extra conservative with the timing on these engines (particularly in the early years), and as a result the car is more sensitive to fuel changes / temperature changes than most cars. When the car has regular fuel and warm weather, the car really seems to loaf around a bit in the 3-4.5k RPM range compared to the other scenarios I mentioned. As you approach 5k RPMs, the cutover to the high RPM cam profile with the variable valve timing is much more pronounced and less natural with the regular fuel / warm weather combination.
Anyways, this is more of an observation rather than an issue. With this being Hyundai's first attempt at a world-class V8, I think it is overall a pretty good effort. I wouldn't be surprised if the 10 HP bump in the later years for the Tau 4.6 was related more to Hyundai figuring out the engine tuning than anything else.
I don't post often on the forums, but didn't see anything else posted on this topic and was curious if anybody else has noticed the same thing. In relatively cold weather (< 50 degrees for here in Florida), the 4.6 in my 2009 Genesis feels much more responsive (particularly in the mid-range) than in 70+ degree weather. I understand the physics of it with the air being more dense, but the difference with this car is much more pronounced than any car I've ever owned.
For those of you that switch back and forth between regular and premium on the 4.6, the power curve would look something like this:
Best - Premium fuel and cold weather
Very Good - Regular fuel and cold weather
Very Good - Premium fuel and warm weather
OK - Regular fuel and warm weather
My guess is that Hyundai is extra conservative with the timing on these engines (particularly in the early years), and as a result the car is more sensitive to fuel changes / temperature changes than most cars. When the car has regular fuel and warm weather, the car really seems to loaf around a bit in the 3-4.5k RPM range compared to the other scenarios I mentioned. As you approach 5k RPMs, the cutover to the high RPM cam profile with the variable valve timing is much more pronounced and less natural with the regular fuel / warm weather combination.
Anyways, this is more of an observation rather than an issue. With this being Hyundai's first attempt at a world-class V8, I think it is overall a pretty good effort. I wouldn't be surprised if the 10 HP bump in the later years for the Tau 4.6 was related more to Hyundai figuring out the engine tuning than anything else.
