The second upgrade (a dashcam was the first) I made to my 2019 G550 was installing decent tires, and the closest size to OE that was available in tires I considered was 275/55R20, which is an inch in diameter larger than the mounted OE Pirellis and 1.4” larger than the 265/50R20 Continental tire MB slapped on as the spare (ostensibly because the OE spare tire cover was a pre-2019 leftover that wasn’t even large enough to fit the OE Pirelli).

I live at altitude in Colorado where it’s possible to get sunburned even on a cloudy day, so leaving a spare exposed to the sun and the weather shortens the tire’s life. I found an aftermarket hard-shell tire cover from Boomerang Enterprises (www.boomco.net) that consists of a black powder-coated steel ring and a PVC face for $430. Boomerang makes tires covers for nearly all vehicles with tailgate mounted spares, and has covers that fit the G’s 275/50R20, 275/55R19 and 275/55R20 tire sizes. Larger sizes are available for Hummers and Jeeps, and these might fit G’s equipped with oversize tires.

The fit is perfect – attached are photos of the tire cover installed on my G. The Boomerang tire ring clasp includes a lock, and I supplemented this with 3 lug nut locks (Dorman 712-680 / M14-1.50) and added sleeves (sure these aren’t theft-proof, but they add a bit more effort to the task).

I didn’t enjoy the view of the spare tire tread and wheel through the rear window even with the OE tire cover, so I purchased a second Boomerang tire face and fitted it on the inside of the spare. As the photo here illustrates, I cut an 8” diameter hole so it would fit over the tire mount bracket, and carved a second opening 3” x 6” to clear the rear wiper pivot. It took a bit of adjustment to rotate this inside cover so it would align properly with the wheel mounting, but this was not too difficult. I also removed the lowest most spare tire mounting stud and spaced it out about ¼” with some 5/16” washers to add a bit of tilt to the wheel and thereby ensure the inner cover doesn’t rub on the rear door.

The cover face looked a bit naked, so I designed and 3D printed an MB star logo (painted matte black), and mounted it at the center. BTW, this slightly larger tire cover does not interfere with the rear view camera’s operation or view. The all black cover seems fine with the G’s Selenite Gray and black trim IMO.

 

Great job...looks totally custom, which iit is! I like the idea of covering the inside of the spare - do you think it will work with the OEM cover?

 

That looks really clean. Nice job. I like the inside cover as well. Might help keep some of the dust, etc. off the wheel as it hangs back there.

 

Nice job. That looks pretty clean. I may have to get one also now for my 2005 since my 32" tires wont' fit under the OE tire cover anymore.

 

The PVC cover piece is only about 3/32" thick so the OE tire ring should fit over it as long as the cover's diameter is within a 1/10 of an inch or so of the tire's diameter. The Boomerang tire ring isn't specifically fab'd to capture front and back covers, but does so without any problem, so I would expect the OE tire ring should capture a rear cover also.