Help understanding rim/tire sizing?

Please bear with me, I have never really figured out this whole rim/tire sizing business.

I have a 3rd Gen. TRD Sport (double cab, short bed if that makes a difference). Stock body, no lift. I would like to get lighter weight wheels for it.

If I'm correct in my research, it currently has stock 17x7.5" rims with the factory 265/65r17 tires.

If I want to get SCS F5's, 16x8", 4.50"BS, +0mm Offset, and keep the same exact ride height/diameter (so that my speedometer/odometer/radar are still accurate, assuming a different diameter would change that), I would need to go with 265/70/r16 tires?

Also, am I correct in thinking that this wouldn't change the width of the tire (it wouldn't really stick out or in any farther), width would still be 265 despite the 1/2" increase in rim width?

If I wanted the wheels to stick out just a little further, would I go with the SCS F5, 16x8", 4.90"BS, +10mm offset?

 

0 offset will stick out farther than +10 if the wheel width stays the same. These will stick out maybe 1/2 " to 1" farther than the stock setup, which looks better IMHO. The tires would poke out just a little on the 0 offset and just about be perfectly even with the fender flares on the +10 setup.

 

Correct, both of those tires would be 30.6” diameter.

The width of the tire would be the same (265mm), but the stock wheels have a high positive offset, so the tires would stick out further with those wheels.

0 offset would push them out further than +10, by 10mm.

 

Helpful links:

 

Thanks, beergeek and Sharpish! This information helps me out a lot.

 

Stock offset is like +26 if I remember correctly. My 0 offset wheels push the tires to the fenders. -10 definitely sticks further out.

 

Check tire mfr and Tire Rack data for tire weight. It's easy to pick the "wrong" tire and gain back all the weight you saved with the lighter wheels.

 

I was curious about that. The factory tires are pretty plain and can't be that heavy compared to something more meaty. Plus the taller sidewall (from going with a 16" rim, but trying to keep the same outside diameter) will add some material/weight. I'll need to be really careful picking the tires.