mazda6 on 92 ron fuel
 

Mazda6 Supersport aug 05 30,000 km

I was wondering if anyone else has found that the 6 runs more smoothly on 92 ron fuel rather than the required 95+ron. We have a shortage of premium fuel at the moment, so I had no option but to use regular unleaded. The engine runs much more smoothly, and gear changes (manual) also smoother.

Are there any negative effects if i keep running this fuel?

Cheers

What you are most likely experiencing is the lower power your engine is producing. When you run a fuel that has a lower anti-knock rating than what the engine was designed for, the ignition system senses "knock" and effectively de-tunes your engine by delaying spark timing (and valve timing as well if your engine is so equipped). The effect is that your engine will feel a bit smoother as it isn't producing as much power.

Long story short, the negative effects of running this fuel are slower acceleration, and lower fuel economy (you'll probably notice a mileage dip large enough to actually make running the low octane fuel more expensive per any given distance than running Premium fuel).

Ok, I have a 2003 Mazda 6 4 cyl. should I be using premium? or just the regular gas? I never though of this before but my guess since I do not have the v6 would be that it didn't matter right?

The short answer is, "Use the exact fuel your Owner's Manual recomends, no better, no worse." That said, given the compression ratio of your engine, I'd "SWAG" that you should probably be using "Regular" fuel.