Tire size & V-bar chain clearance

Recently bought my 2010 Tacoma double cab 4WD. Tires were fairly shot, so I just had new tires put on today, LT255/85R16, the same as what was one it when I got it. The tire size chart on the frame inside the driver's door, though, shows P265/65-R17.

Now I am looking for chains (one set, rear only, just in case...). I have always been very partial to V-bar chains (probably Peerless QG2837, based on my tire size) for the incredible bite they give, but the tire size thing is all a bit confusing. It is not that I cannot find V-bar chains for my tire size; it is that I am wondering if they will give me trouble based on the evidently non-stock tire size on the vehicle.

Comparing LT255/85R16 to P265/65-R17:

1. Why would Toyota recommend P(assenger) tires instead of L(ight)T(ruck) for the Tacoma? Does it even matter? Are the tires I have better. (FYI: the mechanic said it looks like this has maybe a 2" lift using blocks, but I am just taking his word for that part).
2. It looks like the current wheels are 1" smaller diameter than recommended via the spec sheet inside the driver's side door frame.
3. 265/65 means a tire width of 265 mm and height 65% of that, or 172.25 mm; 255/85 means a tire width of 255 mm and height 85% of that, or 216.75 mm. I think this means a difference of 44 mm height per side, which should translate to 88mm larger tire height overall. That is about 3-1/2", less the 1" smaller wheels, means a 2-1/2" larger tire than stock (although I may be completely off in my understanding).

The bottom line, though, is whether I dare put any chains on here. I think I see good side clearance, and it looks to me as though there is still sufficient wheel well clearance for even aggressive V-bar chains to fit.

Do I just trust my eyes here, are there specific measurements I need to take, or has somebody done this exact thing before? Kinda lost here.

 

https://www.tacomaworld.com/tirecalc?tires=265-65r17-255-85r16

 

Get under the truck and carefully measure how much clearance you have at all points including at suspension droop and compression. Then go to the chain manufacturer websites and determine which class of chains you can use. Each class of chain has specific clearance requirements.

 

Thank you, both. That tire size calculator not only makes does all the calculations for me, but provides a way to compare the gear ratios to the factory data. And I will get all the measurements done to determine chain clearance. Peerless chain refers back to owner's manuals, but the owner's manual refers only to chain thickness (side chain 0.2", cross chain 0.25)--which I assume to be at least partially irrelevant now that I have tires that are 2-1/2" larger diameter than stock tires and who knows how much lift. So I am contacting Peerless directly for all the specific clearances on the specific chain I want.