BAKFlip MX4 vs Gator EFX: The EFX Wins Unless You Need the Whole Bed

Fold a BAKFlip MX4 and its panels stand against the cab, so the whole bed opens with the cover still on the truck. Fold a Gator EFX and only the rear two-thirds stacks forward. Its front panel stays down over the first third of the bed, and for the rest you take the cover off, which needs no tools. Past the fold, the two have a lot in common: flush aluminum panels from RealTruck brands, clamp-on rails, and latches with no key of their own, so the bed is as secure as your tailgate lock.

The EFX scores ahead overall, by enough to name it the winner. It cost a good deal less on all five same-truck, same-bed listing pairs we compared, it edges the MX4 on durability, and we rate its leak risk moderate against the MX4's high. Our sealing scores tie, because most MX4s can be sealed a lot drier with an afternoon of work, while a fully dry EFX bed is rare. The MX4 answers with a 400 lb rating to the EFX's 300, 5 years of warranty for the original buyer to 2, a tailgate that works under the shut cover, and confirmed listings for the 4th gen Tacoma, the Tundra, the Maverick and the Colorado and Canyon.

Buy the Gator EFX unless the front of your bed gets used every week. It's the cheaper cover, lets in less water as it arrives and leaves your rear window clear, and when you do need the whole bed, the cover comes off without tools. Pay for the MX4 when you haul tall or full-length loads every week, open the tailgate all day, want a rack on T-slot rails (the MX4 TS), or drive a truck only the MX4 has a confirmed listing for.

The short version

Why the EFX gets our nod on most trucks:

• Price: the lower price wherever both are listed, with the same tailgate-locked security.
• Water as it arrives: a little water at the corners after hard rain is the usual EFX result. Most MX4 water reports describe leaks, at the front corners first.
• The rear window: folded, the EFX's stack stays off the glass. The MX4's leans back toward it.
• Its record so far: EFX covers look new at two years, and one has gone nearly four without a leak. The current MX4 draws complaints about rails that won't seat and faults on arrival.

What the MX4 does better:

• The whole bed, cover on: fold it to the cab and drive with the bed open.
• Ratings: 400 lb evenly distributed and 5 years of warranty for the original buyer, against 300 lb and 2 years.
• The tailgate: it opens and closes with the cover shut. Neither Gator nor RealTruck says whether the EFX's does.
• Racks: the MX4 TS adds T-slot side rails. RealTruck lists no T-slot rail or rack compatibility for the EFX.
• Fit: confirmed listings for the 4th gen Tacoma, the 3rd gen Tundra, the Maverick, the 2023-on Colorado and Canyon, the T1XX 6 ft 7 in bed and the Ram 6 ft 4 in bed with the multifunction tailgate. The EFX answers with confirmed F-150 6 ft 7 in and 3rd gen Tacoma 6 ft 2 in listings the MX4 lacks.

Where they match: both clamp on in what RealTruck quotes as 30 minutes or less with no drilling for the cover itself on most trucks, though the MX4's drain tubes can mean a drill on some trucks. Neither has a key of its own, and neither maker publishes a cover weight.

Two-thirds of the bed or all of it

This is the choice you're making. RealTruck says the EFX folds to expose two-thirds of the bed, with retaining straps to hold it there, and the front third stays under a panel that doesn't fold. The MX4 folds forward on prop rods and leans back toward the rear window, and you can drive with it open. Here's the front third the EFX keeps covered on each bed where both covers have a confirmed listing:

Bed lengths come from the MX4 listing titles. Twenty inches is a third of a 3rd gen Tacoma's 5 ft 1 in bed, and it's the part of the bed a mower, a dirt bike's front wheel or a tall appliance box wants. Those loads mean pulling the EFX, which RealTruck calls tool-free and quick-release.

The MX4's fold has costs of its own. RealTruck says the third brake light stays clear, and on an F-150 the stack clears the bed camera, but on a Colorado it blocks the view out the back entirely, and on a Tacoma it pressed on the rear camera and the prop rods wouldn't seat with the cover folded all the way up. Those rods pop out, and their clips can break. The EFX's stack never reaches the glass.

The tailgate is the other daily difference. The MX4's dual-action tailgate seal lets you open and close the gate with the cover shut. Neither Gator nor RealTruck says whether the EFX's tailgate works under the latched cover, so try it in your first week with the cover, while sending it back is still simple. On a work truck that's in and out of the tailgate all day, that's a real point for the MX4.

Side by side on paper

BAK and Gator both sell through RealTruck, so every row but the last comes from RealTruck's pages. The last row is our own leak-risk gauge.

The MX4's extra 100 lb is margin for snow, not a shelf. Both figures assume weight spread over the entire shut cover, and RealTruck gives neither one a figure for weight concentrated in one spot, so don't stand on either cover or park a loaded cooler on a seam. With either one shut, the bed is as secure as your tailgate lock.

The warranty gap is three years, with fine print on both sides. BAK's 5 years cover the original buyer only, so a used MX4 comes with none. The EFX's 2 years cover material defects, and the 30-day Gator Guarantee, which lets you swap for another Gator cover if you're unhappy, applies only to covers bought on RealTruck.com, so an EFX from Amazon doesn't get the swap. And BAK's longer coverage won't cure a leaking MX4: replacement covers have leaked just as badly as the originals.

Water: a damp corner or a leak

The EFX keeps more water out as it arrives, which is why its leak-risk gauge reads moderate and the MX4's reads high. On the EFX, a little water at the corners after hard rain is the normal result, most often at the rear corners by the tailgate, and fully dry beds are rare. Most MX4 water reports describe leaks: the front corners next to the rear window first, then the tailgate end, then the side rails, with hard rain the usual trigger. BAK calls some leaking normal for the MX4. Each one's full water record is in our Gator EFX review and BAKFlip MX4 review.

Our sealing scores still tie, because the two respond to work differently. The MX4 sits down inside the bed rails and carries water along channels to drain tubes at the front of the bed, so a rail even a few millimeters off lets water past. Silicone along the rails, weather stripping under the rail seal and at the bulkhead, a tailgate seal and careful alignment have all taken MX4s to a dry bed, and some stay dry from the start. The EFX's fixes are simpler and its ceiling lower: seat the bulkhead seal snug against the front of the bed, fit the drain tubes and route them out of the bed, and expect a damp corner in a storm anyway.

• Gator EFX: keep silicone off the cab end. It stops the drip, but it glues the front panel down and you lose the quick removal that makes the two-thirds fold livable.
• BAKFlip MX4: plan the drain tubes before you install. On a 4th gen Tacoma the bed's drain hole is 5/16 in and the MX4's tube is 5/8 in, so you drill or fit a barbed reducer, and some owners drill the front wall of the bed instead. The tubes clog and the hoses can pop off, so check them after the first storms. The install guide for your truck governs any drilling.
• Either one: if a drop-in liner covers your drain holes, plan the routing before you clamp the rails. Keep cardboard, electronics and paperwork out of the corners or in a sealed tote.

Finish, latches and how they age

The EFX edges the MX4 on durability, mostly because today's MX4 hasn't earned the old one's record. Earlier MX4s ran five to nine years. The Gen 3, which RealTruck re-engineered with new latches, clamps and seals, draws complaints about rails that won't seat, clamps that don't stay tight and faults on arrival, from a broken latch to latches installed wrong at the factory. EFX covers look new at two years, and one has gone nearly four without a leak, past its 2-year warranty, though that record is shorter and thinner.

• Finish: the MX4's matte top scratches easily and can dent under a snow broom, and hail has trashed one. On the EFX, the semi-gloss coating is the part we'd watch in hard sun, where one owner saw a Gator fade; treat its top like paint.
• Hardware: the MX4's prop rods pop out, its fold seals can crack early and its plastic latch parts get brittle with age, with replacement parts slow to arrive. On the EFX, the rail track fixed to the underside of the cover can rip out, which looks like a pop-rivet repair rather than a new cover.
• Winter: in hard-winter climates the MX4's foam-core panels can take on water and get heavy to fold. RealTruck says the EZ-Lift version cuts lift force to 10.5 lb.
• Version: the long records on both describe older builds: the MX4's five-to-nine-year covers predate the Gen 3, and RealTruck now says the EFX is made and assembled in Mexico, while a few older Amazon listings still say USA.

Both go on with clamps, and both installs go wrong at the clamps. Each MX4 clamp has to click up into a groove in the rail before the rails sit flush. EFX installs go wrong with the wrong clamp set or a missing clamp, so check the box against the instructions first. Look either cover over the day it arrives, before it goes on the truck, so any shipping claim stays simple.

Which trucks have both

Each cover comes as a separate listing for each truck and bed, and we count a fit only where we confirmed it on the listing's own Amazon page. The tables with the picks give the years, part numbers and each listing's restrictions.

• F-150 (Gen14, 2021 on, and Gen13, 2015-2020): both fit the 5 ft 7 in bed on each generation, and both Gen14 5 ft 7 in listings name the Raptor and Lightning. The EFX adds confirmed 6 ft 7 in listings for both generations; the MX4 adds the Gen13 8 ft 2 in.
• Silverado and Sierra 1500 (T1XX, 2019 on): both fit the short bed, which Amazon calls 5 ft 10 in and RealTruck calls 5 ft 8 in on the EFX. The MX4 listing says it works with the MultiPro and Flex tailgates and won't fit the CarbonPro bed. RealTruck says the EFX won't work with factory bed storage boxes and says nothing about the MultiPro or the CarbonPro, so ask before you buy if you have either. Only the MX4 has a confirmed 6 ft 7 in listing.
• Ram 1500 (DT): the tailgate decides it. Both fit the 5 ft 7 in bed without the multifunction split tailgate; RealTruck says the EFX's 5 ft 7 in isn't compatible with the split tailgate and needs a TRX's bed bar removed, though the Amazon listing mentions neither. On the 6 ft 4 in bed the confirmed listings split: the MX4's is for trucks with the split tailgate, the EFX's for trucks without it and without RamBox. RealTruck sells both MX4 tailgate versions in each bed, plus separate RamBox parts, and lists no RamBox EFX.
• Tacoma: both fit the 3rd gen (2016-2023) 5 ft 1 in bed. The MX4 is built around the factory track system and keeps the rails, though they end up sitting lower; RealTruck says the EFX's short-bed cover won't work with factory bed storage boxes. Only the EFX has a confirmed 3rd gen 6 ft 2 in listing, which excludes Trail Edition trucks. On the 4th gen (2024 on), only the MX4 has a confirmed 5 ft listing, which RealTruck says requires Toyota's deck rail system; RealTruck sells 4th gen EFX parts we couldn't confirm on Amazon.
• Tundra (3rd gen), Maverick and Colorado/Canyon (2023 on): MX4 only, with confirmed listings for the Tundra 6 ft 7 in, the Maverick and the Colorado and Canyon 5 ft 2 in. The Maverick listing reads 2021-2026, though the truck launched for 2022. RealTruck sells EFX parts for all three that we couldn't confirm on Amazon.
• Ranger (2024 on): neither is confirmed. The MX4 listing's product page didn't show the fit clearly enough for us to confirm it. The Amazon EFX listings read 2019-2025, but RealTruck lists those parts for 2019-2023 and sells a separate part for the 2024-2025 Ranger, and a 2024 Ranger owner who bought the Amazon part found the brackets didn't line up. Buy by RealTruck's part number for your model year.

Pick by how you load the truck

• Groceries, gym bags and a commute: the EFX. You'll rarely miss the front third, and you keep the money and the view out the back.
• Tall loads every few weeks: the EFX, if pulling the cover now and then doesn't bother you.
• The front of the bed every week: the MX4. Fold it to the cab and drive, with nothing to unclamp or store.
• In and out of the tailgate all day: the MX4, whose tailgate works with the cover shut.
• A rack: the MX4 TS on its T-slot rails.
• A dry bed above all: neither. The LEER HF650M in the picks needs no drain tubes and keeps more water out than either.
• Snow country, parked outside: if you want the MX4 there, look at the EZ-Lift version.
• Coverage past year two: the MX4, bought new; its 5 years cover only the original buyer.
• A 4th gen Tacoma, Tundra, Maverick or Colorado: the MX4, the one with a confirmed listing. On a 3rd gen Tacoma 6 ft 2 in bed, the EFX is.

Our pick, and when to pay more

We'd buy the Gator EFX. It locks the bed under a flush hard cover, keeps more water out as it arrives, leaves the rear window clear and saves you money. Seat the bulkhead seal, route the drain tubes out of the bed, check the clamps whenever the cover comes off, and keep anything that can't get damp out of the corners.

Pay for the MX4 when the front third of the bed matters every week, when the tailgate gets opened all day, or when your truck has only an MX4 listing. Look it over the day it arrives, route its drain tubes out of the bed, and plan an afternoon of seal work before you trust it with anything that has to stay dry.