What average pace to aim for at London...?

Hi there, I am doing london in three weeks. I have been following the runners world 3.45 programme and have followed it down to the T! I did fleet half marathon last weekend in 1.41 average pace 7.43 per mile. And yesterday did 22 miles in 3.10 which averaged 8.38 per mile. I felt pretty comfortable for this. I am desperate to get sub 4 hrs at london and ideally would love sub 3.45 just wondering what is realistic and what sort of pace people would suggest I go for? I know it depends on variations like weather, how I feel on the day etc. I am conscious of not starting out too fast and would rather wind it up later if i'm feeling strong. Most of my runs I have been doing negative splits so used to this. Any ideas/help would be appreciated!

That's good running.

The one thing I would point out is that it's quite misleading to make a connection between a given schedule and the target time.  Some runners can follow a "3:45 schedule" and do nearer 3 hours, some will be slower.  So don't get held back just because you think your schedule might not be sufficient for your target time.  I feel many runners hold themselves back because of this; you sound to me like your 3:45 target is well within reach.

If you've trained well for the distance then double your half time and add twenty minutes is a rough future. So sub 3.45 seems very doable.

Set out at a steady pace say 8:20-8:30 and if you feel good the last 4-5 miles pick it up a bit. Mind you at London depending on your start pen you will unlikely be able to do your planned pace the first 2-3 miles due to crowding, narrower road sections and even people walking. If so don't panic you have plenty of time to make this up. So don't think you have to run a cuple of 7min miles to catch up. Just 5-10 sec faster a mile for a while is fine - better to run an even paced effort and negative split.
From your HM time and the training you have done sub 3:45 is totally possible. You could probably get nearer 3:30 but for your first better to have an achievable target, get the experience then next marathon you'll have a better idea of what you are capable of. Good luck!

My times have been pretty much the same as yours and I have also been following that plan.  I used it last year and got sub 3.45, but I think I can go faster this year...I'll aim for around 8.30's, but if I am a little faster then I won;t train to reighn it in too much.  I'm green start...what are you?

Thanks for all of the advice people, I think I will look to aim for 3.45 and see how I get on...I can appreciate the first bit being very hectic. I'm in the blue start - who knows if thats good or not!

Blue start is fine If you were green I would have offered to run some with you. Good luck!