Regular VS Premium?? 2.5L
 

Ahoy! On the 2.5 turbo engines. Has anyone really noticed a major difference in performance? I know you get 250hp with premium vs 225 with regular, but still 310ft lb torque. Wondering if it's really worth continuing putting premium considering how pricey gas is.

Wait, you buy a top end turbo model, and then you want to feed it fuel with lower detonation resistance than it was designed for? Did I get that right?

How does this answer the question I posed?

What does your Owner's Manual say; that should carry a lot more weight than what a bunch of schmucks on the internet say.

Given there are very few Mazda6 2.5 turbos out there, you are certainly welcome to play guinea pig and report back after your engine blows up. :p

And you've contributed nothing beneficial to this conversation. Please go troll other new members will you.

Believe it or not, like it or don't, I've given you very good advice.

I suspect that no one on the forum has had a chance yet to buy the Mazda6 with the 2.5t engine, make it through the break-in period and compare the performance with regular versus premium gas. You can be the first and contribute your results to the community.

I have heard that with other vehicles, there is also a difference in performance between different brands of fuel.

Shipo has provided valuable guidance. Don't let the opinions of anonymous people on the internet (myself included) convince you do anything that is contrary to what is documented by the manufacturer. There is a clear difference between premium fuel being recommended and required. I suspect since they give the power rating for both grades of gas, premium is only recommended and it may not harm the engine if you run on regular, however, I would not try it until I was sure.

The other point Shipo raises is that you have paid for a higher performance engine, why not get all of the performance you paid for by paying the slight premium for premium.


On another note, cut people some slack when they provide information on a forum. If you don't think they add value to the conversation, ignore the comment and move on.

On the Mazda website they do provide ratings on both regular and premium and it doesn't dictate in the manual not to use regular fuel, or to only use premium. This engine was designed to utilize both grades. I've had turbo engines in the past where they advise you must use only premium fuel. My question was just to see if anyone has had any feedback with regular VS premium but to your point it's possible this data is not readily available thus far. Looking forward to seeing the information gathered of the differences down the road. Pun intended.

Hello Pico1,

I'm also curious about that. Once I've broken my engine in, I will be seeing for myself if there is any noticeable difference. As for wither it is safe or not to use a lower grade of fuel; 87 octane is considered as safe in Canada for the lower hp and 93 octane is recommended if you want the 250hp.
I'm no mechanic but I was under the impression that the engine would adjust for the different octane in the fuel and perform as well as it is capable with that level of octane. One thing I am confident about is that your engine will not blow up from using the lower octane fuel, providing it is from a reputable gas station and the octane level meets the lower recommendation found in the owner's manual.
When in doubt about what you are reading on an open forum, you could always talk with your local dealership and ask them the same question about octane being recommended verse required etc.