Recently bought a 2016 AWD RDX Tech. Has 18" Michelins (235/60 R18) on it but the spare is 165/90 R17. I've been concerned that the owner(s) before me simply popped something in there to fill the space. No surrounding foam as I've seen in pix here. But in reviewing posts I get the idea that the spare I have is the OEM tire. Can that be correct? Can anyone confirm for me that this really is the original and correct spare for this car? Would relieve my mind ... and my pocket. Thanks.

One other sidebar: I've come to rely on the terrific advice from certain online forums for questions like these. One of my first tasks after buying the RDX was to identify the most active and valuable. I'm pretty certain this is the right place for my (often stupid) questions. Thanks to everyone for the help.

 

2018 RDX Adv Tires are the same 235/60R18 and spare is the same 165/90R17

 

My MDX has 20" tires and a 17" spare!

 

Same full-size and spare tire sizes for my 13 RDX-TECH...it appears that all the 2nd Gen RDXs use the same tire size. It's always been my understanding that AWD/4WD systems are intolerant of mismatched tire diameters...even though the full size and spare rim diameters are different on the RDX, the overall diameter of the full size tire calculates to be 29.1" and the overall diameter of the spare calculates to be 28.7. I guess the Acura engineers determined that is close enough for the short-mileage use the spare is intended for.

 

Not the kind of engineering expertise we've grown to expect from Honda and especially for their high-end products. Really curious as to why they would do that. In the long run what really matters to me is the knowledge that it wasn't a ringer in the used car I bought. May still discover nasty surprises but I don't feel like I need to worry about being stranded without a spare. Still unhappy about the amount of body roll at speed but the posts I've read seem to tell me it's a common complaint and not a fault in mine. Be nice to think maybe better shocks or sway bars might help but I'll give it some time. Thanks for the response.