Yes, if you use it for uses where you will be in the garage for periods of time during cold or hot weather.

"it depends" - where do you live? My garage doors have always been insulated, and it's a mixed blessing. In the summer, the garage heats up from the car engines and we manage that temp by opening the doors in the early mornings. In the winter, when it's COLD, it sure is nice.

The r value is great - but if the install and the trim around the doors leak like a sieve, then the straight through R value is of little help.

Insulated windows are nice, but..... I'd focus on sealing.

The higher R value will minimize heat from radiating into the garage in the summer when the sun hits it ... that may be good or bad, depending on where you live.

Do you plan extended time in your garage? Are you temperature sensitive? We lived on the Peninsula, in Palo Alto, for many years in an Eichler with uninsulated garage and wooden garage door. I never felt it was uncomfortable, but I didn't spend days at a time in there either! :-)

I don't plan to spend extensive amounts of time in the garage. It will have some storage space in it and the typical in and out of the garage with cars.

I would not bother in your climate / area/

The insulation may keep the door from rattling too much.

Living in Michigan and in a small home, we use the garage as extra grocery storage. Its wonderful having insulated doors that help keep some of the heat lost from the house inside the garage so onions as well as beverages like juice dont freeze and go to waste. Plus, that increase seems minimal in a cold climate. Go for it!

Are you going to be different? You're not going to park on the driveway and use your garage to store 'stuff'? (Something I see a lot in warmer climates with small, but expensive homes.)

I insulated my garage door myself after I moved in back in the 90's in a effort to help reduced the heat a little bit. The garage is west facing in Phoenix. HD carried 2' x 4' styrofoam sheets that fit perfectly into the door cavities. The end result, I didn't notice much, if any, difference before and after. In fact it probably hurt the night time temps since the heat couldn't get out as easily through the steel door. The average temp in the garage in the summer at 4:30am when I go to work is still around 100℉. Thinking about it now it didn't make much sense to insulate the door since none of the rest of the garage is insulated. But putting in the white sheets made the garage noticeably brighter at night with the lights on so all was not lost. If I had it to do over again I would just paint the inside of the door white.

chisue - In my neighborhood probably at probably close to 1 out of 3 homes use the garage for storage and park their cars in the driveway. These are smaller (<1500 ft²), but cheaper houses. It has more to do with the fact that almost none of the houses here have basements to fill up with stuff so they fill up the garage instead. I never really understood this but their are a ton of people that do it.

I've never bothered with an insulated door in our climate where November through March the average temp is below 32˚ F. and days of sub 0˚F. are not unusual. When occasionally working in the garage, I'd use a 240 AMP construction heater.

Once you average the R Value of the garage door, the windows and the gaps--the whole wall R Value, that is--you will be nowhere near the R Value of the insulation itself.

DIY foam board insulation on a garage door attached to a dwelling is dangerous and likely against Code without a thermal barrier.

I've decided to not go with the upgrade after hearing your comments here. Thank you!