When to start fueling in a race

Am training for an October marathon and am generally happy with taking a SIS Go Gel every 5 miles during the marathon. However, was wondering when others tend to start taking them. How far into the race? My pre-race meal will be a bowl of porridge, slice of toast (perhaps with chocolate spread) and then nearer the start a banana and bottle of lucozade sport. I am guessing I will be fine until at least 10 miles but want to amke sure I am fueling sufficiently in advance so I don';t run dry too early towards the end.

Thanks in advance.....

I broadly followed the SiS recommendation for my first marathon:
http://www.scienceinsport.com/event-running-marathon.html

I was a little sceptical as they also provide a guide for a half marathon, and if you've eaten properly, i can't see the need over that distance. Anyway, back to the marathon, I tried their guide, and I didn't crash and burn - so will do similar next time. I think I started at 45 mins for the 1st gel, then approx 30min intervals thereafter. Start taking them before needing them - they take 20mins or so for the energy to be available.
Other than for trialling them in training, I never use them on long runs.

Thanks Also-Ran. I have been taking a gel at about 8 miles on my slow runs (this is in the morning after just a banana and bottle of Lucozade) which I guess is about 76mins in. I have wondered if I am taking it slightly late as I do notice the 'pick me up' after another couple of miles which I guess means that I am gradually losing energy, although not noticably as I am running at training pace. I have some race pace running planned in a few weeks time so will try taking gels at your suggested times and also on one run will take at mile 8 and then every 4/5 miles and see the difference. I hadn't looked at the SIS recommendations as I have found that in the past the manufacturers seem to suggest too small a gap between gels for my liking as they tend to leave me bloated but then this has been Lucozade gels and I have now shifted to SIS as they seem to agree and I like the isotonic gels.

It's not uncommon to drink a half bottle or even a full bottle of a sports drink just before the start or to take a gel then.  It honestly depends on how well trained you are at using fat as a fuel source and how hard you are pushing.  If you're not that well trained and pushing as hard as you can then taking gels from the start as often as your body can absorb them is a good strategy.  If you're really well trained and doing it as a training run then you probably won't need any.  You need to decide where you lie on the spectrum and plan accordingly. 

Yes, agree with Clearly. It is good to try them out on a run, but in general I do all training runs, including long runs with water only.

For SiS isotonic gels, the packet says every 20 mins. Their marathon advice is every 30 mins. Personally I never notice a 'pic me up' feeling - the fact that I didn't blow at the end is what i was after from the gels.

Thanks guys. have been trying to keep gel use to a minimum on training runs so what you say makes sense. Will keep trying out during the new few months.

Cheers.