Originally Posted by jlseagull
I'm still waiting to hear if from people who actually use Regular on the X-Fire, or decided to test to see if it works as well...My initial results so far are encouraging (and FYI, I drive the X-fire like it's meant to be driven, and noticed no change in performance)...in fact, I seem to be getting an extra 4 MPG using regular over premium! Weird.
Wait no more! I have been using regular 87 octane since my first fill up April 2004; have over 23,000 kilometers (approx 15,000 miles) and have never heard any pinging / detonation. Car has been completely problem free and never been back to dealer for service.
BTW, on our recent trip to Florida in April, I was getting over 30 miles per U.S. gallon consistently on the highway (average 5 - 10 miles over speed limit driving).
The only mods I have made is, full dual exhaust and free flow air intake. Needless to say, I would not take the risk of aftermarket 'performance' re-chipping.
I don't believe that premium gas is required despite what the manufacturer recommends. They would invalidate the exhaust but for what reason; the engine runs much more efficiently.