R-value describes the power of the insulation in your door. The higher the r-value, the stronger the insulation. Those doors will have better energy efficiency than doors that have a low r-value. Basic doors have an r-value of 0.0 with no insulation. The first step up gives you 1-3/8” insulation at a 6.5 rating. Next, a 1-3/8” thickness with Intellicore has a 12.9 r-value. The best option on the market is the 18.4 r-value, which has 2” Intellicore insulation.
8.5 Inspect the bearing. Lube it with motor oil, spray lithium, or spray lubriplate grease. Do not use WD-40. If the shaft is worn and the bearing is seized and you can't free it, replace the bearing. Or, if you have bearings labeled "ADH" we recommend replacing them. I find very few other bearings that need to be replaced. However, if you do need to replace the bearing and you do not have a new one, you can replace it at a later date. You'll find a quick way to do this at our End Bearing Plate Replacement instruction page.