Thanks man. I am going to run a 255/30/20 front and 305/25/20 rear Nitto Invo tire.
Do you think a 5MM will be better? The reason I am asking without measuring is that I will be getting the wheels shipped with spacers and I don't want to hassle with trying to find good spacers around my city, as they are slim to none.
The wheels have no lip, they are full faced so I want them to be sitting perfectly flush on the fenders with the H&R springs I have installed. What do you think?
Thanks man!
It's really difficult to calculate when you don't have a set of the rims mounted with the tires you'll be using, beforehand. If you're super picky, I would order them without the spacers, get them on the beast and then measure to your liking. If you don't want to wait and you're not super picky, I would probably just do 5mm spacers in the front and 7mm in the back, but it's a complete guess and could be wrong.
You have something else to consider too -- if you're lowered with H&R springs, you're dropped about 1" (25mm). The stock wheel/tire diameter of an M6 is about 27". The tire sizes you've selected are about 26" diameter, so you will have a full inch of wheel well space above your tires (that you don't currently have if you're running the 255/40/19 & 285/35/19 stock M6 tire sizes).
I ran into the same problem when shopping for my 20" wheel/tire combo and had to give up the wider tire size I wanted. The problem is that there aren't any manufacturers that I like making the tire sizes (for the diameter) that would work (and I don't want to be any lower than the H&Rs currently have me). Additionally, you have to worry about other things like speedometer and such when you change the overall rolling circumference from stock.
Unfortunately, most manufacturers don't have anything in the
optimal 20" size that would give you a more aggressive tire width and still keep the factory 27" diameter. 255/35/20 fronts and 295/30/20 rears accomplish this but unless you want to shell out the money for PZeros or PZero Corsas, you're pretty much out of luck for anything that I would deem a worthwhile tire. That being said, I don't even think PZeros are available in the front size. I basically just gave up and took some comfort in the fact that with the wider rim width, the tire would still be slightly wider in terms of actual "section width" (contact area of the tread when mounted on the rim).
At the end of the day, I just chalked it up to splitting hairs, really. What's the actual difference in road holding ability between two tires from the same manufacturer with a difference in section width of .2"? :dunno: I'm certainly not going to lose sleep over that.
Sorry I couldn't be more help.
-b.
