Premium Fuel in High Compression Engines.

[JockoT]

Originally Posted by trollbait

The "or higher" phrasing is likely for the ignorant. Letting them know it is safe to use higher octane fuel in the event they couldn't get the recommended octane.

That is my reading of the situation.

[peteo48]

Good explanation of the "or higher" wording. I suspect you may well be right. I think I have been reading too much into it.

[Airstreamer67]

My '15 Mazda3 2.0 liter automatic has a 13:1 compression ratio. It was designed to run on US-grade RUG, and that's all I feed it. I've never heard any signs of detonation "knock," and I consistently get higher-than-EPA fuel economy, so I've never been tempted to pay more for higher-cost premium.

[SteveMak]

If you're interested in real info on...

• Which octane fuel to use and why?
• What if I use higher octane fuel?
• Which fuel gives me the lowest cost per mile?

...then these three videos are worth a watch. Yeah, you might not like the guy, but his info is spot on. Lots more info that's in line with these facts.

Should I use hi octane premium petrol, and what is octane rating?
https://www.youtube.com/watch?v=WYlk9C1o0nk

Which Fuel Drives Your Dollar Further?
https://www.youtube.com/watch?v=CfEcZWwdjoo

Should I Use Premium Fuel In My Car
https://www.youtube.com/watch?v=La2Rt-_FL8E