Triedaq – appreciate your reply. I’m well-aware of the desire to “ditch” the spare tire. They’re rarely used, but take up a lot of space and are expensive to provide. Hence, the “compact spare” or donut, which is much smaller and cheaper, and will allow the car to be driven a relatively short distance at low speed until the failed tire can be repaired or replaced. However, I got neither with my Caddy. In fact, I suspect the compressor/sealer unit, which is powered from the car’s 12V battery, is more expensive than a donut. My guess is that a donut causes drive-train problems with this car. That’s what I’d like to try to get confirmed.