Honestly I believe the overall diameter is very important even on the FWD. When I mounted factory T165/90R17
Sounds like he started the 19th hole before the golf game.And that's the reason I ditched the factory spare and sourced a 17" wheel and tire combo that has the same diameter as the road tires.
Long side story: After I got the 17" wheel I put the factory spare on Craigslist. I included a picture, said what it came from, and said the wheel was a 5x114.3 lug pattern. Some guy called and said he'd take it for my $50 asking price. Great, gave him my address and waited outside for him to show up. Pretty soon, here he comes down the street, driving faster than what is considered ok for a neighborhood with kids. Now most people park on the street and walk up the drive, but not this guy, he blows up the driveway and stops close enough that I took a step back in self preservation. He's driving a Mercedes. Middle-aged overweight guy gets out, rambling about being late for a golf game and says he's in a hurry. I ask him what kind of car he's buying the spare for and he points at the Mercedes. Says he "lost the spare that came with the car." My head is spinning. First of all, how do you lose a spare, and second, this one won't fit. I tell him it has the wrong lug pattern for a Mercedes but he won't listen. Says it's a 5 lug wheel so it'll fit. I tell him again it isn't right for his car and he responds with "You don't even know what you're selling." He hands me a $50 and says "Just put it in the trunk." Not "would you" or "could you", this jerk is ordering me around at my own house! Fine, some people gotta learn the hard way so I toss in the spare and off he goes.
He calls the next day and says the wheel I sold him won't fit. I'm shocked, lol. He's not too upset though, because he "found" the factory spare he lost. I told him I had good news, that I hadn't gotten around to deleting the ad on Craigslist yet. At this point he's probably thinking I'll take the spare back and refund his money. I told him all he had to do was copy and paste my ad... and then replace my phone number with his.