This came as a shock to me, but I've been riding for 4 months on tires that were 15 PSI and 12 PSI over mfg recommended!!!!
I bought a tire pressure gauge today, and noticed all my tires were about 45 PSI. I changed it to spec for the 3.5, 33 in front, 30 in the back, and I noticed a difference. So much for dealers prepping your car right... For anyone that hasn't done so.. check your tires you might be in for a surprise.. 