So is 5x114.3 the same as 5x115? Im almost positive ive seen people here say this. But then googling the question gets you answers anywhere from, "its perfectly fine" to "youre gonna die" so...

The reason I ask is because I wanna swap wheels on my z31 and I have several sets that are 5x115 (having several montes and bonnevilles in the past.. Ive kept all the wheels). The Z is 5x114.3 with stock offset of 20. How will that offset affect where the wheels with sit inside/outside the fender OR is it compatible at all?

I know this may be better asked on the z forums but id still like to get opinions here, more trustworthy you know? ...Only cause ive come to "know" the regulars here.

Thanks btw!

Oh stock offset of the Montes are 52mm. (Just so nobody has to take more time looking it up.

 

They're 100% NOT the same. One is a metric pattern (115mm) the other is std (4.5").

With that said, the BP difference is pretty small - about .030" so wheels generally fit either as the stud holes aren't machined to the exact diameter of the studs. Because 115 is a bit of an oddball, lots of Wbody people have run 114.3s thoroughly proving it's feasible. Whether it's a good idea or not is up to you to determine. As you noted, there's plenty of information both ways out there.

It's not really a question of if it adds stress - it most certainly does. The lug nuts will self center due to the seat design, pulling the studs in (or pushing them out depending which way you're going) ever so slightly. Not having the shear stress data for the studs you're using or a way to determine how much of that the car is likely to use under use, you've really got no way to calculate how safe it is. Critical fasteners like that will have notable safety margin, it just depends how much of that margin will get eaten up by the change.

You wont get anyone to take the liability of saying you're good to go, which is why I'd personally not suggest it. With that said, I did run a setup like that for almost a decade on my monte.

IMO this is more likely to be the deal breaker. You're talking about 1.25" difference in offset which is substantial. Can always just test fit one to see how out of whack its going to be.

 

Just the person I was looking at for an answer.. Im not looking for anyone to give me the go ahead, actually the opposite. Didnt want to wonder if all these wheels could have been used after spending money on new ones and at the moment im not able to be lifting the wheels to test fit them..

Thanks much!

 

One thing to further support it is all of the people who used to run mustang wheels on GPs. Used to be super common with plenty of examples online and lots of miles driven. Only issue I've ever heard of is the offset thing, especially when people were using aftermarket mustang wheels that were even further off on offset from OEM, that's the only reason I pointed that out.

I certainly wouldnt do it for a critical application (say a 200 mph road course race car), but for just putting around the street, you're not using a fraction of the stud strength. There is always the option to put in a stronger material ARP stud to gain back more margin there if weak studs are a common issue on your other car.