I've never had a post time out on me ...
Here's what I do when I know I'm going to be a while: I open a second tab on the same web page, click on the New Posts button, and set the auto reload addon tool in my browser to about 5 minutes. Or, you can post it part way through, and then immediately edit it. Also, if I think I may have timed out, I Copy the whole thing to my clipboard before clicking Post - for our friend Justin Case.
In looking at the brochure, I notice that the hydraulic series hybrid needs to have the same engine as the conventional car - and I'm assuming that this is because the accumulators are not able to buffer the energy for a longer time? This brings up the issue of warmup time - the engine must be cycling on and off fairly rapidly - what sort of time frame for this to drive at 55MPH on flat ground in no wind? Does the engine run constantly, or cycle on for 3 minutes and off for 3 minutes - what would be typical?