BAKFlip MX4

BAKFlip MX4 review: the short verdict

The BAKFlip MX4 is the hard folding tonneau cover we recommend to most pickup owners, and it's the #1 pick in our F-150 guide after 14 months of daily use on a 2024 F-150 SuperCrew with the 5.5 ft bed. It earns that spot on three things: matte aluminum panels that lock down and resist prying, a sealed perimeter that keeps a daily-driven bed dry, and a fold-and-prop design that opens most of the bed in seconds without taking anything off the truck.

It is not the cheapest hard cover, it is not the lightest, and it is not the right answer for every tailgate. The rest of this review covers exactly where it fits, where it doesn't, and how it stacks up against the covers people cross-shop it with.

What the BAKFlip MX4 is

The MX4 is a hard folding tonneau cover from BAK Industries: rigid aluminum panels with a matte black finish, hinged so they fold toward the cab. You can open the bed one section at a time for a grocery run, or fold the whole stack forward and prop it upright behind the cab for near-full bed access. Closed, it sits low and flush with the bed rails, and the panels can carry a light load on top.

• Material: matte aluminum panels
• Weight: about 52 lb on a 5.5 ft bed
• Install: clamp-on, no drilling
• Warranty: 3 years
• Price band: premium ($$$) — priced per truck and bed length

14 months on an F-150: what held up and what didn't

The MX4 lived on our 2024 F-150 SuperCrew through rain, highway miles and the usual daily abuse, and it also spent a month on a 2023 Raptor with zero seal issues from off-road driving. The things that stood out:

• The seal does its job. In normal rain and car washes the bed stays dry. That is the main reason to buy a hard folder over a soft roll-up.
• The matte finish ages well. It hides light scratches and doesn't show swirl marks the way gloss covers do — a real advantage on a truck that lives outside.
• Drain tubes need attention. The one recurring chore: the rear drain tubes can clog with leaf debris. Clearing them is a 30-second job with a piece of wire, but if you ignore it, a slow drain becomes a wet bed. Long-term owner threads report the same thing.
• It's a two-hands cover to remove. At around 52 lb, taking it fully off the truck for a big haul is easier with a second person. Most of the time you won't need to — folded and propped, it clears enough of the bed for most loads.

Fitment: the tailgate and rail gotchas

The MX4 is sold per truck and bed length, so the first step is always to run your truck through the Fitment Checker and confirm your bed length with the Bed Size Finder. Beyond that, a few truck-specific traps:

• Ford F-150 (2015–2026, incl. Lightning): straightforward fit across 13th and 14th generation trucks; we've verified it directly on Lightning beds.
• Ram 1500 with the multifunction tailgate: the standard rear seal blocks the swing-out panel. You need the tailgate-compatible version, and it has to be ordered that way — there's no retrofit kit. RamBox trucks also need a RamBox-specific clamp kit. Details in our Ram 1500 guide.
• Chevy Silverado 1500 with the Multi-Flex tailgate: not compatible — the MX4 is a standard-tailgate cover on these trucks. See the Silverado 1500 guide for what works with Multi-Flex.
• Toyota Tacoma with factory deck rails: the MX4 is designed to clear the OEM deck rail system, which many clamp-on covers bind against.
• Racks: if your crossbars sit closer than about 6 inches to the bed rail, hard folding panels like the MX4 typically need a 1-inch spacer kit.

Installation

The MX4 is a clamp-on, no-drill install that most owners finish in under an hour with basic hand tools. A second person makes it much easier to set the panel stack on the rails and square it to the bed before you torque the clamps. Take your time on the alignment — a cover that's clamped slightly off-square is the most common cause of tailgate-end leaks, on any brand. Paying a shop or dealer is rarely worth it for a clamp-on design.

BAKFlip MX4 vs the covers people cross-shop

Cover	Type	Material	Weight (5.5 ft)	Warranty	Price band
BAKFlip MX4	Hard folding	Matte aluminum	~52 lb	3-year	$$$
BAKFlip F1	Hard folding	FRP over aluminum	~54 lb	3-year	$$$
UnderCover Flex	Hard folding	Composite over aluminum	~48 lb	3-year	$$
Extang Solid Fold ALX	Hard folding	Textured aluminum	~50 lb	Limited lifetime	$$$
BAK Revolver X4s	Hard roll-up	Aluminum slats	~40 lb	3-year	$$

BAKFlip MX4 vs F1

Same family, same fold-and-prop access, same security. The F1 is BAK's flagship with a smoother FRP-over-aluminum top and premium seals; it's slightly heavier and sits at the top of the price range. The MX4's matte aluminum is the more practical finish for a working truck because it hides wear. Unless you specifically want the F1's top finish, the MX4 is the better buy. Compare them side by side.

BAKFlip MX4 vs Revolver X4s

This is folding vs rolling. The Revolver X4s is a hard roll-up: aluminum slats that roll to the cab like a soft cover, which gives you true full-bed access, but the rolled-up slats take a little bed length at the cab and can't carry a load on top the way flat panels can. Choose the X4s if you regularly need the whole bed open; choose the MX4 for the better seal, flat panels and a lower price band than most retractables.

BAKFlip MX4 vs UnderCover Ultra Flex

UnderCover and BAK are sister brands, and the Ultra Flex shares most of its DNA with the MX4 — same aluminum panel approach, same drain system, same latching philosophy. The Ultra Flex has a slightly more textured finish that hides scuffs even better and usually sells for less. If the MX4 is in stock at full price and the Ultra Flex is on sale, take the Ultra Flex.

BAKFlip MX4 vs Extang Solid Fold

The Extang Solid Fold sits exceptionally low and flush and carries a limited lifetime warranty; its thicker ribbed panels also flex less under heavy snow. The MX4's advantages are the matte aluminum finish that resists scratching in harsh climates and the fold-and-prop access. Snow belt and longest warranty: Extang. Outdoor-parked work truck where cosmetics matter: MX4.

Who should skip the MX4

• Silverado owners with the Multi-Flex tailgate — it isn't compatible.
• Buyers who need the entire bed open every day — a retractable or roll-up gives you full access without a panel stack at the cab.
• Tight budgets — a soft roll-up or tri-fold costs far less and still keeps rain and sun off your gear, it just won't stop a box cutter. See hard vs soft tonneau covers.
• Owners who remove the cover constantly — at about 52 lb, it's built to stay on the truck.

Keeping it sealed for years

Clear the drain tubes every few weeks in leaf season, wipe and inspect the perimeter seals a couple of times a year, and re-check clamp tension after the first few hundred miles. That's the whole maintenance list — and it's the difference between a cover that's still dry at year five and one that isn't. Our guide on how to clean a tonneau cover covers the details.