dimensions of fuel canisters???

The 8oz canisters as well as the MSR 4oz canisters are 4.25" The smaller 4oz canisters like Snow Peak and Jet Boil are 3.5".

The MSR canisters are the same diameter no matter what volume. They are just shorter. I know because I accidentally ordered a CASE of the small size. I still have about 40 of them in the gear room…

is it safe to assume that msr has the largest diameter canisters?

> is it safe to assume that msr has the largest diameter canisters?
No.
The Primus and Kovea canisters on my bench are 4.33" across the rim.

Cheers

For easy to buy and find in the US, MSR canisters are the widest. (As Roger points out there are wider but you won't find those often here)

Coleman 8oz (~227g) canisters are slightly wider than Snow Peak, MSR, Jetboil, etc, by about 1mm.

MSR has now dropped the wider 4oz (113g) sized canisters from their line up and replaced them with a new 110g MSR canister that is the same size as Jetboil, Snow Peak, and Optimus (90mm/3.5″ wide).

HJ
Adventures in Stoving