New Member...confused by wheels & tires. 2019 Silverado RST

[Nekark]

Greetings & Salutations.

 

Allow me to preface this by saying:  a)  I've tried searching, prior to this post, and I'm still confused; b) for all the vehicles I've owned, I have to ask each time, because the measurements are taken into account differently.

 

I currently own a 2019 Silverado RST 2.7L, with the stock 18×8.5, 265/65-18. 

 

I'm looking into getting 18×8.5 +30mm, 5.94" backspacing, with 275/65-18.

 

Stock suspension, no spacers.

 

I know the speedo will be off a little, but what else am I not thinking of?  I know this is the King N00B of all question; and it is the most asked question on every automotive forum, and for that I sincerely apologize...but this whole thing still confuses me.

 

Thank you.

Edited July 21, 2020 by Nekark
Updating text

[Fermy]

Brake caliper clearance. Spokes from mount pad.  Unsure if that backspace will fit depending on the wheel.

[newdude]

The new trucks need the spokes to clear the front calipers, which is why the K2 truck wheel (old body) don't clear without a spacer of some sort.    

 

Diameter wise you are going from 31.5" to 32" tires, so you will read 1mph slower compared to actual travel speed.  Not enough to sweat over.  

[Texasdeere]

2019-2020 Chevrolet Silverado & GMC Sierra 1500 - 2wd & 4wd
Factory 17x8.0 Wheel Offset = +24 mm - Back Space = 5.44" Inches
Factory 18x8.5 Wheel Offset = +26 mm - Back Space = 5.77" Inches
Factory 20x9.0 Wheel Offset = +28 mm - Back Space = 6.10" Inches
Factory 22x9.0 Wheel Offset = +28 mm - Back Space = 6.10" Inches
Lug Pattern = 6 x 139.7
*** Please note: Brake caliper clearance has changed on the 2019+ GM vehicles.

 

2014-2018 Chevrolet Silverado & GMC Sierra 1500 - 2wd & 4wd
Factory 17x8.0 Wheel Offset = +24 mm - Back Space = 5.44" Inches
Factory 18x8.5 Wheel Offset = +24 mm - Back Space = 5.70" Inches
Factory 20x9.0 Wheel Offset = +27 mm - Back Space = 6.06" Inches
Factory 22x9.0 Wheel Offset = +24 mm - Back Space = 5.94" Inches
Lug Pattern = 6 x 139.7

 

2007-2013 Chevrolet Silverado & GMC Sierra 1500 - 2wd & 4wd
Factory 16x7.0 Wheel Offset = +31 mm - Back Space = 5.22" Inches
Factory 17x7.5 Wheel Offset = +31 mm - Back Space = 5.50" Inches
Factory 18x8.0 Wheel Offset = +31 mm - Back Space = 5.72" Inches
Factory 20x8.5 Wheel Offset = +31 mm - Back Space = 5.97" Inches
Lug Pattern = 6 x 139.7