The large, mostly solid, outer tread blocks greatly help dry cornering by reducing squirm and increasing the contact patch in this highly loaded part of the tire. Like the Nitto NT05, the Invo features a solid center rib which helps straight-line stability and braking. The inner shoulder of the tread is nearly solid except for a few sipes which gives a large contact patch for better all-around grip. This also helps resist wear in cars that have a lot of negative camber. Although the inner blocks are pretty solid, siping is woven through the blocks to evacuate water while locking together under dry cornering loads to act like a solid tread block giving the best of both worlds – decent dry and wet grip.
The Invo has a UTQG wear rating of 220 vs the 140 of the NT05 due to the longer wearing high silica tread compound. Silica helps grip in wet and cold conditions while a dry summer tire typically has more polymer and less silica in order to make it sticky in warm weather. This higher UTQG will translate into a long tread life on our heavy performance sedan. On the other end of the spectrum we have the NT555 G2 we had on our M5 previously which has a UTQG of 320. This means the Invo has a compound hardness somewhere in between the NT05 and the NT555 G2.
For wheels, we selected the super strong and light weight Advan Racing GT forged wheel. These wheels are manufactured by Yokohama Wheels and are 4 staged forged. The first 3 stages form the wheel center and roughly form the barrel. The final stage is roll forming, which is a forging like process where the barrel is rotated over a fixed mandrel to form the final barrel dimensions. This is sort of like a potter’s wheel for aluminum. This roll forming refines and improves the grain structure of the aluminum and gives a significant amount of strength to the wheel.
Thanks to the team over at Mackin Industries we were able to test fit and spec out the perfect fitment for our E39 M5. We chose the Yokohoma Advan Racing GT in 19×9 with a +20mm offset for the front and 19×10 with a +22mm offset for the rear. We chose the “Extra Deep” option for both front and rear wheels and they were also ordered with a Semi Gloss Black finish. These were the absolute largest wheels that could be stuffed into the M5’s wheel wells.
Thank you to our friends at our local America’s Tire in Carson, CA. We send all of our tires over to them to get mounted. They have a lot of experience handling expensive wheels and have all the necessary equipment to ensure our tires are mounted correctly and without any damage.
The slender 5 spoke design looks great and really shows off our big StopTech Trophy brakes. Most importantly, they also allow for more cooling air to circulate around the brakes. An added benefit of the simple and open 5 spoke design, is that the wheels are extremely easy to keep clean. Much easier than the stock mesh wheels!
Before we could permanently mount our new wheel and tire package, we had to deal with a fitment issue unique to the E39. The center bore for E39 wheels must be 74mm. Unfortunately, the E39 is the only BMW, that is not an SUV, with such a large center bore requirement. This means wheel options are very limited since most BMWs have a 72.5mm hub diameter.