The OS 65, 75 and 95 AX engines are of the same case size. The 65 is the lightest at 25 ounces with muffler. The 65 is great for most 45-60 size planes as its a great running engine and I think it has more power than a Fox Eagle 60. The 75 has just a tad more power but weights more. The 95 has a bunch more power and is lighter than the 75.

So if you plan to get the 75 forget that an get the 95 you will be much more happy with it...