If a set of wheels are designed to use flat seat lugnuts, is it dangerous to use aftermarket conical seat lugnuts? I want to buy a set for my stock Evo 8 wheels but they are conical.

 

Do not use them, regardless of what others tell you and do.

 

That dangerous huh? Is it a seating issue or just thread engagement?

 

If they are designed for flat then use the flat ones. You are asking for big trouble otherwise.

 

I'll third that. Only use a "Mag-style" lug nut with attached washer:



Along with Mitsubishi, this style is also used on a lot of Toyotas. It'd sure be nice if some companies made some different options for this part...

 

Yea stick with flat ones, I would never attempt to switch them up.