Currently running the OEM spare until I figure something else out. Might just remove it altogether for the time being.
This has been discussed before, but just a heads-up, if you should get a flat or a tire that's a slow leaker, beware of using a different size spare tire!
You'd be better off with a can of Slime, tire patch kit with compressor or some other form of patch kit.
If you put a different size tire, in your case the spare being undersized and you travel very far on that combination, you WILL wind up your drive train and cause thousands of dollars (read: $,$$$) in repairs at your favorite Lexus dealership.
The issues is that our vehicles are NOT part time four wheel drive. Unlike some of the models of 4Runners (some models are all time four wheel drive) and most all other 4x4's (especially trucks) which are all
part time four wheel drive, GX's are FULL TIME all wheel drive. So all wheel drive means all the tires are able to get power at any point in time as the onboard computer deems necessary. Thus having a tire with a smaller circumference will cause
that axle to rotate faster than all the other axles (wheels) thus causing the drive train, e.g. axles, transfer case, differentials to bind up. When that happens something VERY expensive is going to break.
Again, just a heads-up.
