IMHO, most performance mods will decrease your real world fuel economy, simply because in the back of your head is the thought: I spent money for better performance, and I'm here to collect! Like my ol man used to say: it takes oats to feed them horses. I used to be the guy that was always monitoring his mpgs. But unless I think there is something wrong, I stopped paying attention. There is much more satisfaction in running a vehicle like some one else is buying the fuel. I've never had a Honda that didn't like to rev.
What is the cold start issue you guys speak of?