Just a quick 2 cents: 16" tires ride better than 18" (or greater rim diameter) because the sidewalls are not as stiff. Consider the weight of a G Wagen... the 18" tires have to be of significantly lower profile (70 vs 60 vs 50 etc) to maintain the same overall tire diameter that the manufacturer had in mind when designing the vehicle. To support a G's weight, the sidewall must be stiffer as the sidewall profile becomes shorter. The 70, 60, 50 etc profile means that the tire's profile is that percentage of the tread width which is why the 22 and up rims have tires that look like rubber bands with respect to the sidewall height. The additional stiffness of the sidewall to allow such a tire gives the stiff ride but allows higher cornering speeds because the tire, at higher G loads doesn't have the propensity to roll over upon itself. That's ideal for high speed cornering or track use on an appropriate vehicle. That same "short sidewall" is not compatible for anything beyond light trail use especially in circumstances that warrant "airing down". You will also find slicing of the sidewalls on sharp rocks to be a potential problem.
That said, I had an '08 G500 and loved it! Never had any problems with it and only sold it (stupidly, wish I still had that silver beast!!!) because my plans changed. Never mind the nay sayers! Get it out and enjoy it! If you like the low profile tires for the street that's fine. It's your vehicle.Eventually you'll figure out if your present tire and wheel combination are working for or against you. If there is any "rugged" off roading in your future you may want to opt for a second set of rims with aggressive off road tires suitable for your area like the BFG mud terrain vs the all terrain tires (or whatever brand you prefer). The G is still around because it is simply an amazing design! Congrats on your ride!!!
That said, I had an '08 G500 and loved it! Never had any problems with it and only sold it (stupidly, wish I still had that silver beast!!!) because my plans changed. Never mind the nay sayers! Get it out and enjoy it! If you like the low profile tires for the street that's fine. It's your vehicle.Eventually you'll figure out if your present tire and wheel combination are working for or against you. If there is any "rugged" off roading in your future you may want to opt for a second set of rims with aggressive off road tires suitable for your area like the BFG mud terrain vs the all terrain tires (or whatever brand you prefer). The G is still around because it is simply an amazing design! Congrats on your ride!!!