skippyz71

Update: I ended up getting the answers I needed through several phone calls and they all agreed, 275/70/18 will fit no problem with the stock rims, offsets, and suspension. Stock rims keep the tire centered in the middle of the wheel housing with no issues on that diameter/width tire, its when offsets change from factory is when 275/70/18 will rub on these year trucks. Tire Rack said they err on the side of caution with upsize sizes and that's why that warning came up proactively. They didn't see any problem since the overall size is the same I have currently have on 20in rims with only a 2mm offset difference. Thanks.

Was looking for some knowledge or insight. Will a 275/70/18 (Diameter 33.2 x Width 10.8) tire fit with no rubbing on a stock 2020 z71 RST using the stock 18in rims and stock suspension, NO leveling or lift installed? The reason I'm asking is the truck came with factory 265/65/18 tires (Diameter 31.6 x width 10.4). I upgraded to factory accessory 20x9 rims and factory size 275/60/20 tires (Diameter 33 or 33.1 x width 10.8) which fit fine as it is a factory size. I also upgraded the spare to the correct matching size with a brand new takeoff for next to nothing and dealer reprogrammed BCM's to the new tire size. Now the problem, since I still had the stock 18in rims, I wanted to get a set of winter tires that matched the diameter of the new 20in tires. After researching I came up with the 275/70/18 as a recommended 33in matching overall size to the 20in tires with no apparentred red flags. I was about to pull the trigger on tires in that size, but in some last minute reaserch on Tire Rack a warning came up that 275/70/18 would not fit "Without at least a 2in lift" Now puzzled why two similar overall sized tires won't fit the same. I researched more and now found some remarks in forums that 275/70/18 won't fit stock trucks? I then came across this information, looks like factory 2020 GM 20in and 22in rims have a (28) offset. Factory 18in is a (26) offset, is this the difference why 275/60/20 and 275/70/18 (Both about 33.2 x 10.8) fit differently? So can anyone validate 275/70/18 will not fit? If so it looks like I'm seeing if: 275/65/18 (Diameter 32.1 x Width 10.8) 265/70/18 (Diameter 32.6 x Width 10.4) Will fit. Leaning towards the later, closer diameter. Thank you to anyone with information or advice.

**Edit: it came back the next day. I finally got the message to stop. With the truck running and in park, from the home screen went into "Apps", then too "My Apps". All the apps had a "Open" or "Trash Barrel" choice except the Amazon Alexa and Weather channel apps, they add a update box instead of a open icon. Took me a couple tries, but hitting update to manually do the updates finally worked. Watched it do the upload and the update box changed to the open icon. No more messages flashing on the infotainment screen. I was also logged into my home wifi at the same time, don't know if that made a difference?