I've just finished a Hardcore playthrough, using my less well set up ME2 playthrough and I got somewhere in the 3000s as EMS. No multiplayer so readiness rating was permanently stuck on 50%. Bastard out of town store I bought ME3 from didn't include the online pass code, so I can't get online and didn;t realise until I got back to my home town. Have e-mailed EA support, but got no joy from them yet.

Just starting out on my Insanity Playthrough with my much better set up ME2 character. I'll play through anyay, but I just want to know if it's worth the effort to try to get to 4000 EMS.

Edit: oh yeah, according to this article it's possible, though all the commenter's say otherwise. http://slimgamer.com/mass-effect-3-perfect-ending-multiplayer-confusion/

I got close on my first playthrough, reaching almost 3900 EMS, but never overcoming the 4000 barrier without the MP.

And now it's pretty fruitless to try it, since I've promoted so many characters on the MP that's virtually impossible for me to get anything less than 2500 EMS, no matter what .

before the cerberus mission with 15 side missions left i had 4080

I'm sure i did all the side missions along with the DLC and finished the game with somewhere in the region of 6700 if i remember correctly lol

6700 EMS or TMS? Those are two different things. EMS factors in the Galactic Readiness x the TMS, so if your GR is at 50% you should have half your TMS value. A 6700 EMS value with no MP played means that you should have 13400 TMS and that's impossible since there's only about 10K TMS in SP assets.

you need 5000 to get best ending

I had around 3900 before the the last set of missions. Had to do MP to get it over the limit. I actually truly detest this, as if I feel like getting nostalgic in 5-10 years and want to replay this series, I won't be able to get the best ending. Hopefully, Bioware will do some sort of patch that gives you 100% GR after they stop supporting multiplayer, doubtful though, we know how much they actually care about us.