[E4ODnut]

Sorry to shock you into reality, but unless you are very knowledgeable in the art of engine tuning, and are prepared to spend a lot of time and not a small amount of money in the process, what you are seeking is not achievable.

The bottom line is that all the OEM manufacturers of factory EFI equipped vehicles have done a very good job of compromising power, economy, reliability and emissions concerns. Any gains you will get in one area will be hard won and will negatively affect the others.

I have considerable experience in tuning my engines for economy so I'd like to think that I know what I'm talking about. I also have a 91 Sprint and a 91 Miata in my stable. They work so well from factory that I wouldn't even consider modifying them. My Sprint is a $900 beater with almost 300,000 km on the clock. It averages 58 mpg Imperial in summer, 56 in winter. I don't know how I could improve on that.