1.Is a superchips bluefin worth it for a standard st220?
2. What's the effect on fuel economy ?
3. Is it easy to do yourself?

I know this has been discussed many times before but search on my phone is next to impossible.

 

On a totally standard car, for the money I think its worth it. It sharpens the throttle response and smooths out the power throughout the rev range, and give a little more power over 5k, but its not as aggressive as a DS map, however its half the price of the Pumaspeed handset (which uses the old DS maps) so if your on a budget there isnt much choice. Wait till its on offer and go for it.

It does give a couple more mpg in my experience and its very easy to install.