Does the 2.5L NA engine benefit from premium fuel?

You can google all you want, but my tripometer that shows an additional ±50kms a tank doesn't lie.
Sorry, but unless you conduct a test under strict consistent conditions, this claim that you can get an additional 50kms out of a tank of high test is highly suspect.
There are so many factors affecting mpg's that you need to duplicate exactly the same conditions for an accurate comparison. Things like driving style, road conditions, weather, city vs. highway driving etc. all play a part. For all we know, you got an extra 50 kms by driving less aggressively, mostly on highways, compared to aggressive city driving with 87 octane in the tank. Conduct a proper test, using the same routes, same speed, same driving style etc., and maybe you will get a better idea of actual performance.
Better yet, like someone mentioned, put the N/A engine on a dyno with both grades of fuel, and see the results. I suspect the difference will be negligible. The key here is, document the process and do a proper analyses.

I've been around the block a few years, and have switched from high test, to regular, to mid-range, and back to high test in many vehicles over many years. I was also a Company fleet manager for many years in my business life, and can tell you that higher octane gas didn't make a hoot of difference in any vehicle that was recommended by the manufacturer to run on 87 gas. Total waste of money. In a more personal situation, as many of you know, I had a Nissan Pathfinder for 18 years. The user manual recommended premium gas. I got tired of spending extra cash for no observable gain in mileage or performance, so in the last ten years of it's life, I ran regular gas in it. Guess what? No problems with the engine, ever. No knocking, no difference in mpg's, and certainly no difference in performance.

At the end of the day, it's still a personal choice. If people want to spend extra money running premium gas in a vehicle that the manufacturer recommends you use regular, then by all means, carry on. The oil companies will love you.
 
@clownshoes2 Does the regular and premium gas you use have the same percentage of ethanol?
An interesting little tidbit:

-to increase gas' octane rating, companies add ethanol, when they're mixing up a batch of premium fuel. Interestingly, ethanol actually contains less energy than untreated gas, so the net result from the ethanol component is a reduction in your MPG. Other premium additives, however, have the reverse effect, and slightly increase your MPG. So overall, premium provides a very slight net increase in MPG, but it's so slight that you won't notice the difference.

I have read similar statements on many sites, so I doubt this is bogus. An extra 50kms per tank using premium? I don't think so. sorry.
 
You didn't say you were saving money. I said you were wasting it.
You are.

Agree with Buzzman. Your money, your car. We're just trying to help you save money because for some effed up reason, we care and want to help you save money. :D
 
Is there a benefit? It would seem so, if you are getting improved mileage. But can it really be called a benefit if the dollar per km cost is higher because of the increased fuel price, as highlighted in @7eregrine's example? IMO, the answer is no.

The 2.5L engine is designed to run on regular. If you are getting engine knock while running regular, and switch to premium to eliminate the knock, then that is another benefit - but only if you're experiencing engine knock. If there's no engine knock with regular fuel, using premium isn't going to change anything because there's nothing to fix to begin with.
 
AND they would tell you this in the manual. Like Saab did.
In my old Saab car manual, it clearly and specifically said:
"We recommend the use of 89 or better fuel, but your car will run fine on most 87 rated fuel. If you are running 87 and notice pinging, this is not harmful to your engine, but running a higher octane will eliminate it"
Obviously not word for word.
Mazda would have SURELY mentioned if there was any benefit to running higher octane no matter how minor. The Mazda NA just isn't all that advanced. Again, it's excellent, it's reliable, they last forever... and that's probably part of why. It's just a pretty basic engine. And that's ok. :D
 
You didn't say you were saving money. I said you were wasting it.
You are.

Agree with Buzzman. Your money, your car. We're just trying to help you save money because for some effed up reason, we care and want to help you save money. :D
I'm not trying to save money, nor did I ask you to try and save me money.
 
An interesting little tidbit:

-to increase gas' octane rating, companies add ethanol, when they're mixing up a batch of premium fuel. Interestingly, ethanol actually contains less energy than untreated gas, so the net result from the ethanol component is a reduction in your MPG. Other premium additives, however, have the reverse effect, and slightly increase your MPG. So overall, premium provides a very slight net increase in MPG, but it's so slight that you won't notice the difference.

I have read similar statements on many sites, so I doubt this is bogus. An extra 50kms per tank using premium? I don't think so. sorry.
I'm not asking you to believe me. My trip doesn't lie. Just because you're emotionally attached to a viewpoint A) Doesn't make it correct and B) Doesn't invalidate others experiences. You're being a bit judgemental and not accepting and that's not cool in 2021.
 
Buzzman is not emotionally attached to a viewpoint. It's not a 'viewpoint'
It's science.

"In a consumer notice, the Federal Trade Commission, notes: “In most cases, using a higher-octane gasoline than your owner’s manual recommends offers absolutely no benefit. It won’t make your car perform better, go faster, get better mileage or run cleaner.”"

"Only 18 percent of new cars require premium. The owners of the other 82 percent waste about $2 billion a year using a gas that provides no benefit."
 
I'm not asking you to believe me. My trip doesn't lie. Just because you're emotionally attached to a viewpoint A) Doesn't make it correct and B) Doesn't invalidate others experiences. You're being a bit judgemental and not accepting and that's not cool in 2021.

To be fair, you seem to be emotionally attached to your own viewpoint, being so unwilling to consider that other's experiences have their own merit.

Your experience is anecdotal. It doesn't invalidate the studies that have been performed or the articles that have been written on those studies. A couple of examples of those articles or studies were provided earlier. If you can't provide a credible source that supports your experience, then we simply have to take you for your word.

Your experience is your own. I wouldn't go as far as saying that you're lying, or that you have a magical CX-5 or something, but so far it seems that the vast majority of naturally aspirated engine owners do not experience the same benefits you do.


Now, math has never been a strength of mine, so folks, please be patient with me if I mess anything up here. I'm going to use gas station prices near me for reference - keep in mind that I'm in Canada, so prices are in CAD. I only fuel up at Shell, and I don't have 94 available to me. The highest octane I can get is 91.

Currently, Shell 87 costs about $1.35/L. Shell 91 costs about $1.60/L. For argument's sake, we'll say that I get an extra 50 km by fueling with 91, vs fueling with 87.

56L of Shell 87 would cost me $75.60. Assuming I get 550 km per tank, this works out to about $0.14/km.

56L of Shell 91 would cost me $89.60. If I go 600 km per tank, this works out to about $0.15/km.

I would be paying more per km overall, even with the very atypical extra 50 km per tank you mention. Now, considering that 94 would be more expensive than 91, the cost per km would be even higher. Thus, no benefit in terms of mileage. At best, you can say that you don't have to visit the pump as often. And as I and others have mentioned before, if you are not experiencing engine knock with 87, there is nothing to gain by using a higher octane because there is no engine knock to protect against in the first place.

@clownshoes2, with all of this in mind, if you want to ignore everything and fill your CX-5 with 94, nobody can stop you. But speaking for myself, there is no way that I would spend more money on a higher grade of fuel for virtually no reason.
 
Am going to have to try a tank of premium to see if it quiets the fuel injectors and see if gives increased acceleration and mpg.

When dropped 30 lbs of unsprung wheel weight, noticed actual measured mpg increase as well as subjective, perceived faster acceleration.

Using it more so for the engine noise and am doubtful of increased mpg but will be interesting to see what premium does.
 
On a related topic, l used to use ethanol free 90 octane in my old 2014 CX-5 (just the 2.5 N/A) engine and it always felt better to me. My gas mileage -I recorded everything on Fuelly- was no different but I did feel the car was better. Not very scientific but it made me happy!

At the time, the price was very similar to 87 octane and the cost difference was not much. Eventually they figured something out and the price changed - above that of premium 93 so I stoped using it.

So, does anybody know if ethanol free gas makes a difference?
 
I'm not asking you to believe me. My trip doesn't lie. Just because you're emotionally attached to a viewpoint A) Doesn't make it correct and B) Doesn't invalidate others experiences. You're being a bit judgemental and not accepting and that's not cool in 2021.
First of all, you ARE asking me and others, to believe you.
Secondly, I am anything but emotionally attached to "my viewpoint".
As someone else noted, the only one that seems to be getting emotional is yourself. The only one being judgmental is you.
I am putting forward my own personal experiences and observational facts based on over 50 years of driving (a lot of different cars in that time period). Nothing emotional about it.
I have not observed any benefits of running higher octane fuels, in any cars that don't need it, in all that time. None. That is fact, not emotion.
As others have stated, you do whatever you want at the end of the day. If it makes you feel warm and fuzzy filling your tank with expensive gas, then go for it.

As for the other question that came up regarding ethanol gas vs non ethanol gas, the only thing I can contribute to that is that ethanol is used to raise the octane level, but at the same time, has less stored energy per unit of volume than straight gasoline. Ethanol produces less punch than gas. Theoretically, gas with 10% ethanol will produce less energy than pure gas. It's a tradeoff basically.
 
The only car I have owned that supposedly benefited from higher test gasoline was my ‘12 Focus. It had a high compression GDI engine like the CX5. You were supposed to use 87 octane, but the user manual suggested using 89 octane for “better performance”. I tried a couple tankfuls back to back. The only difference I noticed was slight. On 87 it wanted to downshift fairly early when going up hills. With 89, it was more willing to lug at a lower rpm’s without downshifting. I didn’t continue to pay extra for it, but it was a fun experiment.
 
I have not observed any benefits of running higher octane fuels, in any cars that don't need it, in all that time. None. That is fact, not emotion.
That's your truth. My truth is different. You're not really being progressive in valuing others opinions. Again, not cool in 2021.
 
That's your truth. My truth is different. You're not really being progressive in valuing others opinions. Again, not cool in 2021.
Did you start this thread just to get validation of your opinion? The question of whether a vehicle benefits from use of premium fuel is not subjective. The correct answer to the question is not an opinion. Perhaps you should have asked "Do you feel that the 2.5L NA engine benefits from premium fuel?" Then everyone could have their opinion.

 
The question of whether a vehicle benefits from use of premium fuel is not subjective.
Exactly this. We don't have our own "truths". Facts are facts.

How many times did you run regular versus premium to come to the conclusion that you are getting 50 more KM's on premium? Maybe if you clue us in on your testing procedures we can better analyze your data instead of just taking your word for it?
 
That's your truth. My truth is different. You're not really being progressive in valuing others opinions.

Well, neither are you. Speaking of value, there are some "truths" that are further supported by facts. Your truth is valuable of course, but without any supporting evidence, research or facts, the reality is that your experience is the exception, not the rule. It isn't fair to imply that someone isn't being inclusive just because they're asking you for clarification on what seems to be an exception.

Validating your experience by providing clarifications on your testing process would help improve the credibility of your experience.
 
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