2020 GMC Yukon XL Bulb Size

Misconception: people often think a bulb chart is just a list of sizes that all fit the same way. It seems true because many bulbs share similar bases and numbers, so you might assume swapping is straightforward. I get that; it’s an easy mental shortcut. What is true is a bit more detailed for your 2020 GMC Yukon XL. Think of it as a fitment map that matches lamp type, socket, and electrical requirements, not just shape. A rule of thumb is that the wrong bulb can change beam pattern, heat tolerance, or the vehicle’s diagnostics. Implications and quick recap: use the chart as a starting point, verify with the owner’s manual and a visual check of the socket, and consider a fitment lookup tool. Some links on this page are affiliate links; I may earn a small commission at no extra cost to you.