Give me the pros and cons of each.. The similarities and differences.. 

 

 Always wanted the Pro XS on my next boat but found a great deal on the exact boat I want with virtually every feature I want set up the way I want except it’s got a Fourstroke instead of the Pro XS..

If you're talking New (2019 and newer) the difference between the 150's - ProXS & Four Stroke is minimal at best. 

Both are 4 stroke and 3.0 L, Gear case is a little different & XS weighs 1 pound more; 456 lbs vs 455 lbs.

https://www.mercurymarine.com/en/us/engines/outboard/compare/?e[]=11209&e[]=11214

 

Mercury no longer makes new 150 hp Two Stroke OB's.

The old Optimax & the ProXS are discontinued. 

 

If you're talking older motors of the same or different years, the actual year can show some differences.

You'll need to know what year each is to make an accurate comparison of specs. 

Of course the older XS is a two stroke and may be quite a bit lighter than the older four stroke.

The XS will be louder, require oil & gas mix (which is an additional but necessary cost), but no actual oil change - and will most likely have a more pungent exhaust - (insert smoke a bit).

 The Four stroke should be quieter, smoke less and require oil changes.

 I have deliberately omitted perceived performance differences and which one cost more or less to own / run because IMO - the difference may not be enough to matter on both accounts.

May simply depend on which way you prefer to go.

In the end, as long as the HP is sufficient for your rig, you'll most likely get what you're looking for.

Good Luck.

A-Jay

 

BTW - I recent re-powered from a two stroke Optimax to the new four stroke V8 4.6 L ProXS and I like it quite a bit. 

It’s a 2017 Triton that I am looking at... Thanks for taking the time to reply A.J.! 

Is it a Verado?  I have a 2016 and love it.  It weighs more than the Poe xs but I would not trade for one.  It is so quiet I have to look for the water stream in order to see if it is running.

I've got a new 115 pro xs 4 stroke on my aluminum triton. The more I run it the more I realize I'd hate to have to go back to a 2 stroke.  No adding oil...I almost screwed up my last 250 pro xs forgetting to fill the reservoir. Its soooooo quiet and the fuel economy is amazing.  My buddy has a mid 2000's 115 2 stroke merc and we believe the 4 stroke gets maybe 5 times better fuel economy.  I believe the future of outboards is definitely 4 stroke.