16 tires on 16.5 wheels

[FritzA]

Hi all,

I have a 77 C20. The glove box option sticker says it came with 8.75 x 16.5 wheels. When I bought it, it came with 235/85/16s on it.

I don't think the wheels were changed out ever, does it make sense that someone put 16 inch tires on a 16.5 wheel?

Looking at Firestone Transforce specs, the 235/85/16s have a larger overall diameter than the 8.75 x 16.5. I like the bigger diameter for the gearing on the highway.

If the wheels are the original 16.5, is it safe to put the 235/85/16 tires on them?

Thanks for the help in advance.

[FritzA]

One more question....

Is there a marking on the wheels to tell if they are 16.5 vs 16?

[choptop]

I would hope no one put 16 inch tires on a 16.5 rim. I wouldnt think it would be possible, but working in the oilfeild, I have learned anythings possible. If they did, I would get them changed quickly, but I doubt they did.

[Irish_Alley]

Measure them and see what the dia of the rim is rim to rim

[Irish_Alley]

Prob someone switch out the rim and wheels cause a. 16 maybe a little cheaper or b. They had 16s just laying around or given to them but like chop said anything is possible

[bgctrading]

16s will air up on 16.5 but it is dangerous a 16.5 wheel will have an angle from the lip of the wheel to where it makes the turn down to the off set. A 16 will stay almost flat. A halfway trained eye could tell in a second. If you could post a close up pic I could prolly tell from that but angles are hard to see in pics sometimes.

[bgctrading]

Also sometimes wheels are marked on the back or inside the wheel where you cannot see with a tire mounted.

[Mr Diesel]

All the 16.5 rims I have seen have the size stamped on them. Usually on the outside of the rim and they usually say something about not mounting 16" on them.