shsabh6

Hello all,
I have a 2017 GLC300 whose original run-flats are now worn at 18000 miles (US based, so no spare is available). Been reading these forums to solve my "spare problem" for the past year and was about to go purchase the donut as recommended by others above. Definitely do not want run-flats again !!

However, in a Google search yesterday, I came across a company called Modern Spare (modernspare.com), located in Colorado who have designed donut spares for many run-flat type vehicles. I got in touch with them and they stated that they have a spare for the GLC300, as well. One can configure a spare for the GLC300 on their website. The wheel is designed to handle large brakes also. Approx. $350 + $45 shipping includes wheel/tire, nuts, jack, wrench, cover etc.

Have any of you bought this spare ? Or heard of this company (are they legit) ? Thank you.

ajmtbm

Hi I bought the modern spare, and have a 2017 in the US. Fits neatly underneath. I bought the whole kit, but it won't fit underneath with the cover on.

They shipped pretty quickly, I had a couple questions via email for customer service and they responded quickly. Its a nice looking unit overall, i am very happy with the purchase, now i just have to figure out what non RFT tires to buy.

shsabh6

Thank you for the response. I think I will purchase, too.

Xbowguy

Glad it worked out for you... I was trying to save a few bucks going with the used retro fit spare tire package... I think your option removes all dought about the caliper clearance issues.. My main concern was having it fit in the cargo bay with lid closed.... I had no issues
with that with the MB rim.... Good luck in your non RF tire section. I'll be doing the same research....

Gullikson

Hello, did you find that your spare is pushing hard on the fuse box? I have a US 2018 GLC 300 4matic and testing with 6” thick foam mock-up, the fuse box is in the way.

DanD.

It is on the way but not so bad. Here are some pics

ajmtbm

Same here with the modernspare unit. I had to push down a bit and the top is a little smashed but it doesn't touch any of the fuses or the plastic trim around them. When i did mockups with books to 6" it definitely seemed to first worse than it actually did with the tire, maybe because the little bit of curvature around the tire helps.

tire installed on 2017 US GLC300



Fuse box that sits underneath modernspare tire

ajmtbm

BTW - after much research I ordered a set of Michelin CrossClimate2 which are en route to Costco, so probably in a couple of weeks I will post some thoughts on the spare tire thread

ParjAS

Great!

Gullikson

what year and country is your GLC?

ParjAS

I can see his is an 2018, not sure where he is.

DanD.

Its 2018 and in US

Gullikson

thanks!

Xbowguy

Man those have a funky tread design.. Not sure which ones 'll be getting,, but here in Pa. (us) I need a good all weather tire. I'm still leaning toward Bridgestone Ecopia. costco.

billb8737

I am converting our 2018 GLC300 SUV from run-flat tires (Pirellis worn out at 20K miles!) to non-run-flat, so I have purchased a kit with jack and lug wrench, and the Mercedes-Benz GLK350 17x6 Spare Wheel Rim Vredestein Tire OEM ( 362079764662 ).

Do I need different lug bolts than the ones currently holding the wheels on the car?

I thought I saw somewhere about shorter lug bolts for the spare wheel... Is this for convenience, or required?

Thanks!

Xbowguy

Bill
you're going to need the shorter lug bolts for your spare rim the the STEEL version... if it's a regular mag wheel the same as your other 4 then you can use the factory lug bolts.. If the factory lugs use on steel rim they are too long and will bottom out against the rotors

the shorter lug bolts should be available on Ebay

Good Luck welcome to the Non Run flats club..

seamus2154

This is the most overlooked issue. I bought a spare for my W222 S550 and its from a W221 S63 which is an aliminum mag rim. To my delight it uses the stock lug bolts. On the GLC I bought the ML350 spare and jack which is the stamped steel rim. It NEEDS the shorter lug bolts.

Suggestion: Anyone going this route needs to do a trial run with their new equipment. Correct spare tire pressure (60psi) in my case, use jack (make sure it is correct for application), install lug bolts, use lug wrench . Move car and make sure there are no obstructions or lug bolts hitting rotor. On the side of the road at the worst time is no time to find out you missed something or have an issue.

billb8737

Thanks for the replies - very helpful!

I have put in an offer on a set of the short lug bolts on eBay... the non-run-flats are not yet installed, so I have a little time.

I like the idea of doing a trial wheel change in the comfort of my garage... rather than on the side of the highway...! Makes me think of Leon Russell, "Sitting on the highway in a broken van/Thinking of you again..."

Sugar_Mouth

Just bought a Mercedes Jack kit and ML350 spare tire. The 155/90/18 does interfere with the fuse box housing but does not make contact with any of the components under the housing area. Good to have a spare, now for regular tires.

AK927

After learning of this run-flat problem months AFTER buying my 2017 GLC last year, I switched out the Pirellis for Continental CrossContacts last week. I knew id have to figure out the no-spare situation, but didn't think id get a flat after only 8 DAYS with the Contis. Neither my tire shop nor the dealerships (the two in Vegas are absolutely terrible) were very helpful with how to get a spare so I just ordered the kit from ModernSpare. Just bought the wheel and tire, and am purchasing a better jack kit on Amazon. Will update with photos once it arrives to see how it fits underneath!

Teckno

Notice of Warning for all the second hand spare tire from earlier MB models for your GLC.
Check the date of manuf of your spare tyre, usually 4 numbers, like 4412. Translates into week 44 of 2012.
Tyres should be replaced after 7 years - they do degrade and can delaminate. Makes no real difference that they are in a cool, dark hole in the trunk !!!!
Good luck.
Also if buying new tires, spare the throttle for the first 500km as they have a silicon release agent on the outside to assist extraction from the manuf press - 500km allows silicon type coating to be scrubbed off tyre and then they are good to perform. No point suffering extended stopping or loosing control through tires ‘letting go’ on road surface when turning.

molzahn6

I have a 2019 GLC300 base model. Thanks for all the information on using standard tires! I bought a set of Michelin Defenders and the car rides so much better. Bought a spare kit from Modern Spare after reading posts here. Fits in the trunk over the top of the fuse box perfectly and floor of the trunk latches just fine!

Ranisharma55

So this tyre actually works liek did u used it ? I think I can find it on ebay .

SuperTuscan

@DanD. , Thanks for your post. I have a 2020 4Matic, 18" wheels with the run-flat tires. MB as you may to may not know did not include a spare (*******s &#128516. Can you provide anymore info on your part number and where did you get the wheel/tire? Is that available for a 2020 or it does not matter? I have 18" wheels, unless there's issues with lug spacing, or other issues. Dealer parts says there's no donut available for the 18" wheels but there's a donut for 19". Very strange decision making on MB.
California car.
Thank you for any help.

SuperTuscan

Sharing these pics of the spare donut on a 19" 2021 GLC300. My 2020 was in for routine repair at the dealer in Los Angeles, and this donut was under the rear lid on the loaner car.
I need a spare (as noted in my reply to DanD. under this thread) for my 2020 18". What are the part numbers or what part would work. The dealer said there's no part for the 2020. Part numbers please.