Shouldn't void warranty. You'll need to install longer wheel studs with a spacer, which will likely cost more than the spacer, and can be a pain to install ...... Unless if you're thinking of installing a spacer that bolts to your hub and then has its own secondary studs for the wheel. I haven't seen that type in the 0.75" range, typically that type is when you get into the 1.5"+ range.
Are these for a new wheel? What about changing to a higher + offset and skip the spacer altogether?
Depending on quility of material and/or tolerances in craftsmanship, the only concerns would be ...
1. Makes mounting the wheel (e.g. tire rotation) more difficult since the wheel doesn't mate to the hub anymore, and instead the spacer. If the spacer isn't machine matched to your wheel's center bore, then it'll be more difficult to center the wheel and prevent vibration. Your hub has a female end, if you will, that mates to your wheel's male end. This is what allows you to easily and accurately center the wheel on the hub. Unless your spacer duplicates this, centering is all on you.
2. Depending on what metals the spacer, wheel, and hub are made of ... You might run into one thing "freezing" onto another after a while. Easy fix, just have to remember to put some anti-sieze on either side of spacer every time you do a tire rotation. A little and-sieze goes a long way BUT wear gloves (unless you want it everywhere). Anti-sieze is a mechanic's version of glitter
3. Don't read into this much, but this is something I always consider when starting a mod --> will it cause me grief with my insurance company? You see, everyone is concerned with tampering with their factory warranty, but I ask you "is what you're planning on doing going to allow your insurance company to loop hole or fine print you on a claim?" Devil's advocate will say that an accident could be blamed on altering the steering and handling characteristics from OEM. 0.75" is nothing, but a shady insurance lawyer won't see it that way
EightyModerator / Dream Killer