The Tape Measure Trap: Why Your New GMC Tonneau Cover is 10 Inches Too Short
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You are heading out for a massive cross-country road trip in your 2014–2018 GMC Sierra 1500 Crew Cab. You want to lock your expensive luggage and gear safely out of the weather, so you jump online to order a premium, hard-folding aluminum tonneau cover.
Because your truck has four massive doors, you simply assume you have the "standard" bed. You click the option for the 6'6" bed, wait a week for the massive freight box to arrive, and carry it out to your driveway. You bolt the aluminum rails to your truck, unfold the heavy cover toward the tailgate, and your stomach completely drops.
The cover is physically hanging a full 10 inches past the back of your truck. You don't have a 6'6" bed. Your Crew Cab came with the 5'8" short box.
You just fell directly into the Tape Measure Trap.
The K2XX Sierra platform was manufactured in dozens of different cab and bed configurations. The absolute most common mistake in the entire truck aftermarket is guessing bed length based on the size of the cab. Because premium brands like BAK Industries and Retrax laser-cut their aluminum panels to the exact millimeter of the factory bed, there is zero margin for error. If you don't take 30 seconds to physically measure your box, you are guaranteed to deal with a massive, frustrating return.
You don't have to guess, and you don't have to leave your gear exposed to thieves. You just need to know your exact footprint.
In this guide, we explain exactly how to measure your GMC Sierra's bed from the bulkhead to the tailgate. We'll show you why cheap vinyl covers flap violently on the highway, how Retrax allows you to mount tents above your bed, and how to turn your open box into a secure vault.
Compare Premium Bed Cover Upgrades
Hard Folding Aluminum, Retractable Shields, or Premium Woven Roll-Ups?
|
Cover Style |
Top Brands |
Tech / Build |
Best For |
|
BAKFlip MX4 |
BAK Industries |
Matte Aluminum Panels. |
Maximum Security. The absolute gold standard of tonneau covers. Features heavy-duty, interlocking aluminum panels that sit completely flush with your bed rails. When you close the cover and lock your factory tailgate, your bed is more secure than your cab. |
|
RetraxPRO XR |
Retrax |
Retractable Aluminum. |
The Overland Command. The ultimate in smooth, one-handed operation. The heavy-duty aluminum slats glide effortlessly into a compact spiral canister at the front of the bed. The "XR" series features integrated T-Slot Trax Rails, allowing you to mount crossbars and roof tents directly above the cover. |
|
Pro X15 |
TruXedo |
Woven Matte Fabric. |
The Sleek Street Aesthetic. Ditch the shiny, cheap vinyl look. TruXedo utilizes an incredibly premium, matte-black woven canvas that perfectly matches your factory plastic bed caps. It rolls all the way to the bulkhead, giving you 100% full bed access in seconds. |
Frequently Asked Questions (Bed Covers)
Do I have to drill holes in my GMC Sierra to install these covers?
No, they utilize heavy-duty clamp systems.
Premium tonneau covers are designed to be completely non-destructive. The massive aluminum rails of a BAKFlip or TruXedo simply clamp directly onto the inside lip of your Sierra's factory steel bed rails using a standard socket wrench. Installation typically takes about 45 minutes in your driveway with basic hand tools.
Can I open my tailgate without opening the tonneau cover first?
Yes, on modern premium models.
Older tonneau covers required you to unlatch the cover before you could drop the tailgate, which was incredibly annoying. Premium covers like the BAKFlip MX4 feature dual-action tailgate seals, meaning you can open and close your factory tailgate completely independently of the tonneau cover.
Will a bed cover improve my GMC Sierra's gas mileage?
Yes, but only slightly.
While a premium cover massively improves the aerodynamics of your truck by preventing high-speed wind from dragging against the inside of the closed tailgate, the fuel savings are usually around 1 to 2 MPG on the highway. You should absolutely buy a cover for cargo security and weather protection, not strictly as a fuel-saving investment.
Armor the bed. Lock the gear.
Ditch the flapping vinyl and secure your expensive cargo against weather and theft. Shop our verified collection of premium 2014–2018 GMC Sierra 1500 Bed Covers.