My IM fueling strategy: what do you think?

Well, it's good to see someone that can challenge me in the OCD dept Most important thing is if it works for you in training. If so, then no reason it shouldn't work on race day. Don't do anything new on race day applies to nutrition as much as it does to new shoes, changing seat height, etc.

I have only done one IM, but one lesson I learned was to pay attention to any "warning signs" on the long training days. That is, my stomach felt a little nauseous on some of the long training days, but nothing I thought I couldn't handle. However, unless you are doing 11,12,13 hour training days -> race day will take longer. So those minor nutrition issues have a tendency to become major.

What about your sodium?

I find that the three aspects of nutrtion are all important: hydration, calories and electrolytes.

I agree with above poster that learning to listen to your body while training is key as it helps you adjust if necessary on race day.

You may want to try a back up plan B for nutrition based on what is on the course and do that in a couple long rides to see how it works for you. I had three nutrtion plans and practiced each on long rides/short run bricks so I knew how they worked, had practiced them and knew I had a couple of back up options.

Good point: I always read that in the first hour is better to limit caloric intake, preferring just water and some calories at the end of 1st hr.

I discovered G Fitness which is low in calories, good taste, still has same sodium and other minerals as the normal Gatorade and at the end of the first hr I have some carbs from that plus a gel at the end of that hour.

Does it make sense? What is your plan in the first hour? 

You are right but then I get the Perpetuem warm...I should finish the Perpetuem asap, so from 2nd to 4th. At the 4th hr it is at the limit of temperature to be drunk. If the temperature will be low enough, I will move it forward and get bars before. 

It's taper time now so be careful with the experimenting...  I was between 350 and 400 cal/hour on the bike.  Probably a few more calories than I could actually digest but the goal was to make sure the energy level stayed strong all day.  I don't remember the rationale but my coach disagreed with the low calorie intake the first part of the bike and advised to start taking liquid calories as soon as I got on the bike.  After all, you did just swim 2.4 miles with no calorie intake and you have a long day ahead of you.  I started on Perp as soon as I was off the helix.  Did 14 scoops over the course of the ride.

The banana halves they had at aid stations were awesome.  Bonus 50 calories each if they appeal to you on race day.  I had a couple banana halves, a couple fig newtons, an uncrustable, some gummy sharks, and endurolytes as well.  I can't drink GE all day so I held off on that until the run.

Edited to add:  I assumed you are doing Wisconsin but after re-reading I'm guessing that is not the case.  You may have more time to experiment.  Whatever you try on your long rides needs to taste good at the end.  If you get sick of it faster, it is going to be tough to stick with your plan on race day.

I am going to do Cologne226 Ironman in Germany on the 7th Sept

I read Going Long and there is suggested on the first hour

0-20mins no calories just water

20-40mins 200 calories

40-60mins no calories just water

60-120mins 200calories every 20mins

and then it is written to get as many calories as you can per hour starting trying with 400/hrs and see.

Now the question for me is: everybody says try on yourself and if it works go with that. But if you take lower calories than you can, for sure your stomach will not react. Unfortunately I never tried to get more than 300cal/hr and on my 2x HIM I did, I was always on 250cal/hr.

From that book it seems I am on the very low side of the suggestions. 

I assume you have been training with Perpetuem.

My experience with it was not good.  I used it in training, but on the IM, it was warm, my mix bottle (high concentrate of Perpetuem/water, some liquid carbo pro) got warm and just started tasting foul to me.

This was true on 2 occasions - I no longer can handle the smell of Perpetuem as a result.  That's just my experience, others love it.  I would just say make sure to practice using it on a very long training day. 

After having done sme more readings, I post the update. M.Ryan on her book reports a 0.5gr of carbs per body pound per hour to be used in a IM.