This car comes with 20 inch tires, but I believe you can use a 17 or 18 inch compact spare ( FWD does not come with spare, only AWD includes the spare). I have found the following options for a tire:
155/85 D 18 or 145/70 R17
Can anyone suggest the best size spare to carry?-- and a good source!
Thanks.

Acurod
2005 RL
2013 MDX
2019 MDX
2020 TLX
2023 MDX

 

It just a little bit more for a full size spare. Donut spares are limited to 50 mph max speed and 70 miles max range and can greatly affect handling, acceleration, and braking. I ended up switching out my 18 RLX to a full size spare because I had all kinds of warning lights in the dash when I had to leave my donut spare on for a few days waiting for a replacement tire because of pothole pinch flat. It is also harder to maintain the 60 psi for the donut spare if you don't check often. I keep my 19 MDX full size spare at +45 psi and I only need to check a few times a year under the vehicle.

 

Thanks for that info-- agree about utility of full size versus limited range of compact; however, not sure if the area underneath could hold a full size spare without getting too close to the ground. Anyone have a full size stored under an MDX?

Acurod